SW8050547_Historical File_20210420

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April 20, 2021
RMTH CAROLINA.
ambume"aQuamy
New Hanover County Airport Authority
Attn: Granseur Dick, Facilities
Director
1740 Airport Boulevard.
Wilmington, NC 28405
Subject: State Stermwater Management Permit No. SW8 050547
Wilmington International Airport EDDB
High Density Project
New Hanover County
Dear Mr. Dick
The Wilmington Regional Office received a complete, modified State Stormwater Management Permit
Application for the subs project on April 15, 2021. Staff review of the plans and specifications has determined
that the project, as proposed, complies with the Stormwater Regulations set forth. in Title 15A NCAC 02H.1000
(1995 Rules) as amended on January 1, 2017 (2017 Rules). We are hereby forwarding modified. Permit No. SW8
050547 dated April 20, 2021, for the construction of the built -upon areas (BETA) and stormwater control measures
(SCMs) associated with the subject project.
This permit shall be effective from the date of issuance until June 15, 2027 and the project shall be subject to the
conditions and limitations as specified therein and does not supersede any other agency permit that may be
required. Failure to comply with these requirements will result in future compliance problems. Please note that
this permit is not transferable except after notice to and approval by the Division.
Please refer to Attachment C for a detailed description of the cr7ir vnt proposed major modification and a list of all
the past modifications approved during the effective period of the permit.
This cover letter, attachments, and all documents on Mee with DEMLR shall be considered part of this permit and
is herein incorporated by reference. Please replace the previously approved plan sheets with the attached
modified and approved versions. Please replace the previous application (SWU 101), slzpplemen4 operation and
maintenance agreement with the attached modified versions.
If any parts, requirements, or limitations contained m this permit are unacceptable, you have the right to request
an adjudicatory hearing by filing a written petition with the Office of Administrative Hearings (OAH). The
written petition must conform to Chapter 150B of the North Carolina General Statutes and must be filed with the
OAH within thirty (30) days of receipt of this permit. You should contact the OAR with all questions regarding
the filing fee (if a filing fee is required) and/or the details of the filing process at 6714 Mail Service Center,
Raleigh, NC 27699-6714, or via telephone at 919-431-3000, or visit their website at www-NCOAH.com. Unless
such demands are made this permit shall be final and binding.
If you have any questions concerning this permit, please contact Garrett Zorda in the Wilmington Regional
Office, at [phone] or [e-mail].
Sincerely,
5�; Brian Wrenn, Direetar
Division of Energy, Mineral and Land Resources
Enclosures: Attwhmcnt A —Designees Certification Form
Attwhment C — Permitting History
Application Documents
DESlgdz: %StarmwaterTermits & Projects120051050547 HD1202104 permit 050547
E North Carolina Departnnent of Ehvk=vnental Quality I Division of Energy. Mineral and Land Resources
Wllrnington.Reponal Mee 1 127 Cardinal. Drive Extension ( W&ningtom North Carolina 284os
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State Stormwater Permit No. SW& 050547
Page 2 of 2
cc: Rick Baker, PE Timmons Group
New Hanover County Building Safety Department
Wilmington Regional Office Stormwater File
North Carolina Department of Env6-Ontrental Quality. I Dision of Energy, Mineral and Land Resources
+�• Wgh* wn Regional Office 127 Cardinal Drive Extamsion I Wbnington, North Carolina.28405
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State Stormwater Management Systems
Permit No. SM 050547
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL RESOURCES
DIVISION OF ENERGY, MINERAL AND LAND RESOURCES
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as
amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
New Hanover County Airport Authority
Wilmington International Airport Extended Dry Detention Basins (EDDB)
1740 Airport Boulevard, Wilmington, New Hanover County
FOR THE
construction, operation and maintenance of three (3) extended dry detention basin ("stormwater
control measures" or "SCM") in compliance with the provisions of 15A NCAC 2H .1000 (1995 Rules)
as amended on January 1, 2017 (2017 Rules) (collectively, the "stormwater rules') and the approved
stormwater management plans and specifications and other supporting data as attached and on file
with and approved by the Division of Energy, Mineral and Land Resources (the "Division" or
"DEMLR") and considered an enforceable part of this permit.
This permit shall be effective from the date of issuance until June 15, 2027, and shall be subject to the
following specified conditions and limitations:
I. DESIGN STANDARDS
1. The drainage area identified as Phase I&II is subject to the 1995 Rules and as clarified in the
1995 specific conditions listed herein. The drainage areas identified as Phase IIIA, Phase IIIB
and Phase IIIC are subject to the 1995 Rules and the 2017 Rules and as clarified in the 2017
Rules specific conditions listed herein_
2. This project and SCMs have been approved based on the "Wilmington International Airport
Stormwater Master Plan" document approved on November 24, 2004 as a variation to the
stormwater rules and in accordance with G.S. 143-214.7(c3). All future major modifications to
this permit must either meet the 2004 "Wilmington International Airport Stormwater Master
Plan" in its entirety, meet the most current set of stormwater rules, or provide technical
justification that the proposed modification is providing equal or better control and equal or
better protection of waters of the State as a variation under the current set of stormwater rules.
Approval of such variations that do not meet all of the requirements is done on a case -by -case
basis.
3. FAA requirements prohibit standing water (i.e., permanent pools) and stipulate that the design
storm must be fully drained within 48 hours. This is supported by G.S. 143-214.7(c3) where
the Division does not require the use of an SCM with standing water. The approved SCM
design for the 3 extended dry detention basins includes a low flow device but does not include
a permanent pool at the low flow outlet or sediment storage.
4. The approved "Wilmington International Airport Stormwater Master Plan" document is not
intended to limit or restrict the airport or its current or prospective tenants from pursuing
alternative or modified stormwater management solutions in various locations than those listed
in the document itself. Since the approval of the "Wilmington International Airport Stormwater
Master Plan" document, other stormwater control measure (SCM) options that do not contain
areas of standing water have been developed and should be evaluated for future projects.
Page 1 of 5

State Stormwater Management Systems
Permit No. SW8 050547
5. This permit is effective only with respect to the nature and volume of stormwater described in
the application and other supporting data. The maximum amount of built -upon area (BUA)
allowed for the entire project is 9,304,059 square feet.
6. The three (3) SCMs identified as "Phase I and II" Extended Dry Detention Basin, Phase IIIA
Extended Dry Detention Basin and Phase 11113 Extended Dry Detention Basin have been
designed to handle the runoff from 8,520,835 square feet, 116,598 square feet, and 367,596
square feet of BUA, respectively, within the delineated drainage areas. The BUA for future
development within the drainage areas to the SCMs identifies as "Phase I and I[" Extended
Dry Detention Basin, Phase IIIA Extended Dry Detention Basin and Phase IIIB Extended Dry
Detention Basin is limited to 2,223,812 square feet, 48,788 square feet, and 264,031 square
feet, respectively.
7. Where an individual project within the drainage area is being leased or sold, the stormwater
collection system for that project must be located in either dedicated common areas or
easements and the final plats will be recorded showing all such required easements.
8. The drainage areas for the on -site stormwater systems will be limited to the amounts of built -
upon area indicated in this permit and the approved plans and specifications. The runoff from
all built -upon area within the permitted drainage areas of this project must be directed into the
permitted stormwater control measures.
9. (2017 Rules) The peak flow from the 10-year storm event shall not cause erosion downslope
of the discharge point.
10. (2017 Rules) A 50-foot wide vegetative setback must be provided and maintained in grass or
other vegetation adjacent to all surface waters as shown on the approved plans. The setback
is measured horizontally from the normal pool elevation of impounded structures, from the top
of bank of each side of streams or rivers, and from the mean high waterline of tidal waters,
perpendicular to the shoreline.
11 The portion of the existing airport previously included in the drainage area of the permitted dry
detention basin that is being removed, must be submitted in a future permit application as a
modification or under G.S. 143-214.7(c4).
12. (1995 Rules) The following design criteria have been provided and must be maintained in the
"Phase I and II" Extended Dry Detention Basin.
Phase I & II
a. Drainage Area, acres: 287.63
Onsite, ft2: 12,529,107
Offsite, ft2: 0
b. Total Impervious Surfaces, ft2: 8,520,835
C. Design Storm, inches: 4,552,087 @1"
3,968,748 @1.5"
d. Basin Bottom Elevation, feet: 7.0
e. TSS removal efficiency: 50%
f. Storage Elevation, FMSL: 13.0
g. Storage Surface Area, ft2: 506,082
h. Permitted Detention Volume, ft3: 1,058,112
i. Seasonal High Water Table, FMSL: 6.0
j. Controlling Orifice: 12.0" O
k. Drawdown Time for 12.0"0 orifice, hours: 57
I. Receiving Stream/River Basin: Smith Creek / Cape Fear
M. Stream Index Number: 18-74-63
n. Classification of Water Body: C;Sw
13. (2017 Rules) The SCMs identified as Phase IIIA Extended Dry Detention Basin and Phase IIIB
Extended Dry Detention are permitted based on the design criteria presented in the sealed,
signed and dated supplements, the sealed and signed "Technical Justification" document
dated April 13, 2021 justifying the variations from the Wilmington International Airport
Stormwater Master Plans well as the 2017 minimum design criteria, and as shown in the
approved plans and specifications. These SCMs must be provided and maintained at the
design condition. The approved supplements are incorporated by reference into this permit.
Page 2 of 5

State Stormwater Management Systems
Permit No. SW8 050547
14. (2017 Rules) If the SCMs identified as Phase IIIA Extended Dry Detention Basin and Phase
IIIB Extended Dry Detention are found to not meet the approved design criteria, a modification
must be submitted to either meet the requirements or propose another variation from the rules.
This is based on a case -by -case decision and should not be used as a precedent for future
permitting actions.
15. Tributary projects outside of the drainage area of the previously approved "for -credit" grassed
swales, but inside the drainage area of the approved SCMs, must provide an additional BMP
with a sufficient TSS removal efficiency such that the total TSS removal, including the
extended dry detention basin, is at least 85%.
II. SCHEDULE OF COMPLIANCE
1. The stormwater management system shall be constructed in its entirety, vegetated and
operational for its intended use prior to the construction of any built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of the system
will be repaired immediately. If the stormwater system was used as an Erosion Control device,
it must be restored to design condition prior to operation as a stormwater treatment device,
and prior to occupancy of the facility.
3. The facilities shall be constructed, operated, and maintained in accordance with the provisions
of this permit, the approved plans and specifications, and the supporting documents attached
to this permit and on file with the Division.
4. The permittee is responsible for verifying that the proposed built -upon area for the entire
project does not exceed the maximum allowed by this permit.
5. Upon completion of the project, the permittee shall determine if the project is in compliance
with the approved plans and take the necessary following actions:
a. If the permittee determines that the project is in compliance with the approved plans,
then within 45 days of completion, the permittee shall submit to the Division one hard
copy and one electronic copy of the following:
i. The completed and signed Designer's Certification provided in Attachment A
noting any deviations from the approved plans and specifications. Deviations
may require approval from the Division;
ii_ A copy of the recorded operation and maintenance agreement;
iii. Unless already provided, a copy of the recorded deed restrictions and
protective covenants; and
iv. A copy of the recorded plat delineating the public rights -of -way, dedicated
common areas and/or permanent recorded easements, when applicable.
b. If the permittee determines that the project is not in compliance with the approved plans,
the permittee shall submit an application to modify the permit within 30 days of
completion of the project or provide a plan of action, with a timeline, to bring the site into
compliance.
6. The permittee shall at all times provide the operation and maintenance necessary to assure
the permitted stormwater system functions at the design condition. The approved Operation
and Maintenance Plan must be followed in its entirety and maintenance must occur at the
scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowing and revegetation of slopes and the vegetated filter.
d. Immediate repair of eroded areas.
e. Maintenance of all slopes in accordance with approved plans and specifications.
f. Debris removal and unclogging of outlet structure, orifice device, flow spreader, catch
basins and piping.
g. Access to the outlet structure must be available at all times.
7. Records of maintenance activities must be kept and made available upon request to
authorized personnel of DEMLR. The records will indicate the date, activity, name of person
performing the work and what actions were taken.
Page 3 of 5

State Stormwater Management Systems
Permit No. SV18 050547
8. (2017 Rules) The operation and maintenance agreement must be recorded with the Office of
the Register of Deeds.
9. (2017 Rules) The final plats for the project must be recorded with the Office of the Register of
Deeds. The recorded plat must reference the Operation and Maintenance Agreement and
must also show all public rights -of -way, dedicated common areas, and/or permanent drainage
easements, in accordance with the approved plans.
10. Access to the permitted stormwater facilities shall be maintained via appropriate easements
(as required) at all times.
11. No person or entity, including the permittee, shall alter any component shown in the approved
plans and specifications. Prior to the construction of any modification to the approved plans,
the permittee shall submit to the Director, and shall have received approval for modified plans,
specifications, and calculations including, but not limited to, those listed below. For changes to
the project or SCM that impact the certifications, a new or updated certification(s), as
applicable, will be required and a copy must be submitted to the appropriate DEQ regional
office upon completion of the modification.
a. Any modification to the approved plans and specifications, regardless of size including
the SCM(s), BUA, details, etc.
b. Redesign or addition to the approved amount of BUA or to the drainage area.
C. Further development, subdivision, acquisition, lease or sale of any, all or part of the
project and/or property area as reported in the approved plans and specifications.
d. Altering, modifying, removing, relocating, redirecting, regrading, or resizing of any
component of the approved SCM(s), the stormwater collection system and/or
vegetative conveyance shown on the approved plan.
e. The construction of any allocated future BUA.
f. The construction of any permeable pavement, #57 stone area, public trails, or
landscaping material to be considered a permeable surface that were not included in
the approved plans and specifications.
g. Other modifications as determined by the Director.
12. The Director may notify the permittee when the permitted site does not meet one or more of
the minimum requirements of the permit. Within the time frame specified in the notice, the
permittee shall submit a written time schedule to the Director for modifying the site to meet
minimum requirements. The permittee shall provide copies of revised plans and certification in
writing to the Director that the changes have been made.
13. Prior to transfer of the permit, a file review and site inspection will be conducted by Division
personnel to ensure the permit conditions have been met and that the project and the on -site
stormwater system complies with the permit conditions. Any items not in compliance must be
repaired, replaced restored, or resolved prior to the transfer. Records of maintenance activities
performed to date may be requested.
III. GENERAL CONDITIONS
1. The issuance of this permit does not preclude the Permittee from complying with any and all
statutes, rules, regulations, or ordinances, which may be imposed by other government
agencies (local, state, and federal) having jurisdiction
2. This permit is not transferable to any person or entity except after notice to and approval by
the Director. The permittee shall submit a completed and signed "Permit Transfer Application
Form" (available on the Division website) accompanied by the required fee and supporting
documentation as listed on the form, to the Division at least 60 days prior to any one or more
of the following events:
a. The sale or conveyance of the project area in whole or irk part, except in the case of an
individual lot sale that is made subject to the recorded deed restrictions and protective
covenants-
b. Dissolution of the partnership, corporate, or LLC entity, subject to NCGS 55-14-05 or
NCGS 57D-6-07 and 08;
c. Bankruptcy;
d. Foreclosure, subject to the requirements of Session Law 2013-121;
Page 4 of 5

State Stormwater Management Systems
Permit No. SW8 050547
3. Any individual or entity found to be in noncompliance with the provisions of this stormwater
management permit or the requirements of the Stormwater rules is subject to enforcement
procedures as set forth in NCGS 143 Article 21.
4. In the event that the facilities fail to perform satisfactorily the Permittee shall take immediate
corrective action, including those as may be required by this Division, such as the construction
of additional or replacement stormwater management systems.
5. The permittee grants DEQ Staff permission to enter the property during normal business hours
for the purpose of inspecting all components of the permitted stormwater management facility.
6. The permit issued shall continue in force and effect until the permittee files a request with the
Division for a permit modification, transfer, renewal, or rescission; however, these actions do
not stay any permit conditions.
7. Unless specified elsewhere, permanent seeding requirements for the stormwater control must
follow the guidelines established in the North Carolina Erosion and Sediment Control Planning
and Design Manual.
8. Approved plans and specifications for this project are incorporated by reference and are
enforceable parts of the permit. A copy of the approved plans and specifications shall be
maintained on file by the Permittee at all times.
9. The permittee is responsible for compliance with all permit conditions until such time as the
Division approves the transfer request. Neither the sale of the project, in whole or in part, nor
the conveyance of common area to a third party constitutes an approved transfer of the
stormwater permit.
10. The permittee shall submit a completed "Permit Information Update Application Form"
(available on the Division website) to the Division within 30 days to making any one or more of
the following changes:
a. A name change of the current permittee;
b. A name change of the project;
c. A mailing address change of the permittee;
11 The issuance of this permit does not prohibit the Director from reopening and modifying the
permit, revoking and reissuing the permit, or terminating the permit for cause as allowed by the
laws, rules, and regulations contained in Title 15A NCAC 2H.1000 and NCGS 143-215.1 et.al.
12. A permit renewal request must be submitted at least 180 days prior to the expiration date of
this permit. The renewal request must include the appropriate application, documentation and
the processing fee as outlined in Title 15A NCAC 02H.1045(3).
Permit modified, updated and reissued this the 201 day of April 2021.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Unia '" IS
.3;; Brian Wrenn, Director
Division of Energy, Mineral and Land Resources
By Authority of the Environmental Management Commission
Page 5 of 5

State Stormwater Management Systems
Permit No. SW8 050547
Wilmington International Airport
Stormwater Permit No. SW8 050547
New Hanover County
Designer's Certification
I, , as a duly registered in the State of North
Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the
project,
(Project)
for (Project Owner) hereby state that, to the best of my
abilities, due care and diligence was used in the observation of the project construction such that the
construction was observed to be built within substantial compliance and intent of the approved plans
and specifications.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
Page 1 of 2

State Stormwater Management Systems
Permit No. SW8 050547
Certification Requirements:
1. The drainage area to the system contains approximately the permitted acreage.
2. The drainage area to the system contains no more than the permitted amount of built -
upon area.
3. All the built -upon area associated with the project is graded such that the runoff drains
to the system.
4. All drainage within the permitted contributing drainage area is directed into the system.
5. The outlet/bypass structure elevations are per the approved plan.
6. The outlet structure is located per the approved plans.
7. A trash rack is provided on the outlet/bypass structure.
8. All slopes are grassed with permanent vegetation.
9. Vegetated slopes are no steeper than 3:1.
10. The inlets are located per the approved plans and do not cause short-circuiting of the
system.
11. The permitted amounts of surface area and/or volume have been provided.
12. Required drawdown device is correctly located and sized per the approved plans.
13. All required design depths are provided.
14. All required parts of the system are provided, such as pretreatment devices, outlet
structure and/or forebay.
15. The required system dimensions are provided per the approved plans.
16. The maximum drainage area and/or built -upon area have not been exceeded for the
"Phase I & II" condition.
cc: NCDEQ-DEMLR Regional Office
New Hanover County Building Inspections
Page 2 of 2

State Stormwater Management Systems
Permit No. SW8 050547
Attachment C - Permitting History
Wilmington International Airport EDDB
Permit No. SW8 050547
Appwv#J
Perm -it
HEIRS
>l� - aftfie Chanps
L'
Action
Vey
This original issuance approved the 150 acre area
pocket of high density Phase I, in accordance with
6/15/2005
Original
1.0
SW8 040836, to be treated in an extended dry
Approval
detention basin (EDDB) #1 designed to handle the
runoff from 4,247,100 square feet of impervious
area.
Approved the modification of the permit to include
Phase 11, which brought the total project area to
10/28/2009
Modification
1.1
264 acres and increased the size of the EDDB # 1 to
handle a total of 8,468,064 square feet of
impervious area.
Approved the modification to include Phase III,
which brought the total project area to 321.35 acres
and increased the size of the EDDB # 1 to handle a
10/26/2011
Modification
1.2
total of 8,468,064 square feet of impervious area.
This permit also took into account the impervious
area for SW8 060326 and SW8 060515, which
both drain to EDDB # 1 and were permitted as
Offsite permits to SW8 050547.
Approved the modification to the overall drainage
area to 3 22.3 8 acres and the increased size of
EDDB #1 to handle a total of 9,751,185 square feet
11/29/2012
Modification
1.3
of impervious area. This modification included the
addition of two grassed pre-treatment swales. This
issuance left 3,177,214 square feet of Future
allocation for the Phase I & II area.
Approved the reallocation of 205,202 square feet of
Plan
Future allocation for the development of the Rental
2/8/2013
Revision
1.4
Car Facility within the Phase I & II drainage area.
This issuance left 2,972.,012 square feet of Future
allocation.
Approved the reallocation of 32,453 square feet of
Plan
Future allocation for the expansion of the North
8/4/2015
Revision
1.5
General Aviation Apron draining to EDDB # 1.
This issuance left 2,939,559 square feet of Future
allocation for the Phase I & II area.
Approved the reallocation of a total of 129,082
square feet of future allocation, 62,570 square feet
Plan
for the Business Park access road and 66,512
9/9/2015
Revision
1.6
square feet for Lot 9 of the Business Park, both
draining to EDDB #1. This issuance left 2,810,477
square feet of Future allocation for the Phase I & 11
area.
Page 1 of 2

State Stormwater Management Systems
Permit No. SW8 050547
Approved the reallocation of 122,922 square feet of
future allocation for the North General Aviation
Hangar Taxiline and Corporate Hanger Complex.
6/29/2016
Plan
1
This also took into account the 24,190 square feet
Revision
'7
of impervious area allocated to SW8 150723,
which drains to EDDB #1 and is permitted as an
Offsite permit to SW8 050547. This issuance left
2,663,295 square feet of Future allocation.
Approved the reallocation of 75,596 square feet of
8/22/2017
Plan
1'8
future allocation for the Avis Car Rental Facility
Revision
draining to EDDB #1. This issuance left 2,587,699
square feet of Future allocation.
Approved the reallocation of 29,337 square feet of
4/18/2018
Minor
1.9
future allocation for the Social Bark Kennel
Modification
draining to EDDB #1. This issuance left 2,558,362
square feet of Future allocation.
Approved the reallocation of 110,358 square feet of
10/5/2018
Minor
2.0
future allocation for the FBO #2 project draining to
Modification
EDDB #1. This issuance left 2,448,004 square feet
of Future allocation.
10/3/2019
Renewal
3.0
This issuance renewed Permit No. SW8 050547
until June 15, 2027.
Approved the reallocation of 224,194 square feet of
future allocation for the Air Carrier Apron
Expansion draining to EDDB # 1. This modification
Major
also adds Pre-treatment Swale #3 as pretreatment
10/6/2020
Modification
3.1
for EDDB #1. The submittal also included 9,268
square feet of impervious area that meets NCGS
143-214.7(c4) that does not drain to EDDB #1.
This issuance left 2,223,812 square feet of Future
allocation for the Phase I & II area.
This issuance replaces the originally approved
Phase III expansion (and "Overall" condition) of
Extended Dry Detention Basin (EDDB) #1 with
two new EDDB's. EDDB # I remains unmodified at
the Phase I&II condition. The two new EDDB's,
identified as Phase IIIA and Phase IIIB on the
plans, are permitted as a variation to the rules based
4/20/2021
Major
3.2
on the 2004 "Wilmington International Airport
Modification
Stormwater Master Plan" document, signed and
sealed "Technical Justification " document dated
April 13, 2021, and supplements as shown in the
approved plans and specifications. The Phase IIIA
EDDB has been designed to handle the runoff from
116,598 square feet of BUA and he Phase IIIB
EDDB has been designed to handle the runoff from
367,596 square feet of BUA.
Page 2 of 2

DEMLR USE ONLY
Date Received Fee Paid Permit Number
Applicable Rules: ❑ Coastal SW -1995 ❑ Coastal SW - 2008 ❑ Ph II - Post Construction
(select all that apply) ❑ Non -Coastal SW- HQW/ORW Waters ❑ Universal Stormwater Management Plan
❑ Other WO Mamt Plan:
State of North Carolina
Department of Environment and Natural Resources
Division of Energy, Mineral and Land Resources
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
2. Location of Project (street address):
0 AIRPORT BLVD
City:WILMINGTON County:NEW HANOVER Zip:28405
3. Directions to project (from nearest major intersection):
Southeast corner of the intersection of NC HWY 23 & AIRPORT BLVD
4. Latitude:34° 26' 7030" N Longitude:-77° 92' 1265" W of the main entrance to the project.
II. PERMIT INFORMATION:
1. a. Specify whether project is (check one): ❑New ®Modification ❑ Renewal w/ Modificationt
tRenewals with modifications also requires SWU-102 - Renewal Application Form
b.If this application is being submitted as the result of a modification to an existing permit, list the existing
permit numberSW8 050547 , its issue date (if known)10/26/2011 and the status of
construction: ®Not Started ❑Partially Completed* ❑ Completed* *provide a designer's certification
2. Specify the type of project (check one):
❑Low Density ®High Density ❑Drains to an Offsite Stormwater System ❑Other
3. If this application is being submitted as the result of a previously returned application or a letter from
DEMLR requesting a state stormwater management permit application, list the stormwater project number,
if assigned, NA and the previous name of the project, if different than currently
proposed, NA
4. a. Additional Project Requirements (check applicable blanks; information on required state permits can be
obtained by contacting the Customer Service Center at 1-877-623-6748):
❑CAMA Major ❑Sedimentation/Erosion Control: ac of Disturbed Area
❑NPDES Industrial Stormwater Z404/401 Permit: Proposed Impacts Wetlands
b.If any of these permits have already been acquired please provide the Project Name, Project/Permit Number,
issue date and the type of each permit:l`d ,
5. Is the project located within 5 miles of a public airport? ❑No ®Yes
If yes, see S.L. 2012-200, Part VI: htt}2://portal.ncdenr,=/web/lr/rules-and-regulations
Form SWU-101 Version Oct. 31, 2013 Page 1 of 6

III. CONTACT INFORMATION
1. a. Print Applicant / Signing Official's name and title (specifically the developer, property owner, lessee,
designated government official, individual, etc. who owns the projectl:
Applicant/Organization:NEW HANOVER COUNTY AIRPORT AUTHORITY
Signing Official & Title:DICK GRANSEUR, DIRECTOR
b. Contact information for person listed in item 1a above:
Street Address:1740 AIRPORT BLVD
City: WILMINGTON State:NC Zip:28405
Mailing Address (if applicable):SAME AS ABOVE
City:
Phone: (910 ) 341-4333
Email:G DICK@FLYILM. COM
State: Zip:
Fax: (910 ) 341-3465
c. Please check the appropriate box. The applicant listed above is:
❑ The property owner (Skip to Contact Information, item 3a)
® Lessee* (Attach a copy of the lease agreement and complete Contact Information, item 2a and 2b below)
❑ Purchaser* (Attach a copy of the pending sales agreement and complete Contact Information, item 2a and
2b below)
❑ Developer* (Complete Contact Information, item 2a and 2b below.)
2. a. Print Property Owners name and title below, if you are the lessee, purchaser or developer. (This is the
person who owns the property that the project is located on):
Property Owner/Organization:New Hanover County
Signing Official & Title:
b. Contact information for person listed in item 2a above:
Street Address:
City: State: Zip:
Mailing Address (if applicable).
City:
Phone: f )
Email:
State: Zip:
Fax: (
3. a. (Optional) Print the name and title of another contact such as the project's construction supervisor or other
person who can answer questions about the project:
Other Contact Person/Organization:MEREDITH W. RICE. JR / CIRCLE K STORES, INC
Signing Official & Title:VICE PRESIDENT
b. Contact information for person listed in item 3a above:
Mailing Address:1100 SITUS COURT, STE 100
City:RALEIGH State:NC Zip:27606
Phone: (919 ) 744-6700 Fax: (NONE ) NONE
Email 7A'I.ICE®CIRCLEK. COM
4. Local jurisdiction for building permits: NEW HANOVER COUNTY
Point of Contact:INSPECTIONS DEPT Phone #: [phone]
Form SWU-101 Version Oct. 31, 2013 Page 2 of 6

IV. PROJECT INFORMATION
1. In the space provided below, briefly summarize how the stormwater runoff will be treated.
Stormwater runoff will be treated via two pre-treatment vegetated grass swales which then discharge into
W
2. a. If claiming vested rights, identify the supporting documents provided and the daey were a ro
❑ Approval of a Site Specific Development Plan or PUD Approval Date:NOV 2004
❑ Valid Building Permit Issued Date: 26 OCT 2004
® Other: ILM Stormwater Master Plan Date: 24 NOV 2004
b.If claiming vested rights, identify the regulation(s) the project has been designed in accordance with:
® Coastal SW -1995 ❑ Ph II - Post Construction
3. Stormwater runoff from this project drains to the Cape Fear River basin.
4. Total Property Area: 322.3 acres 5. Total Coastal Wetlands Area: acres
6. Total Surface Water Area: 0 acres
7. Total Property Area (4) - Total Coastal Wetlands Area (5) - Total Surface Water Area (6) = Total Project
Area':322.3 acres
+ Total project area shall be calculated to exclude the following: the normal pool of impounded structures, the area
between the banks of streams and rivers, the area below the Normal Hi h Water (NFIiM line or Mean High Water
(MW line, and coastal wetlands landward from the NHW (or W line. The resultant project area is used to
calculate overall percent built upon area (BUA). Non -coastal wetlands landward of the NHW (or MHIM line may
be included in the total project area.
8. Project percent of impervious area: (Total Impervious Area / Total Project Area) X 100 = 66.27 %
9. How many drainage areas does the project have?4 (For high density, count 1 for each proposed engineered
stormwater BMP. For low density and other projects, use 1 for the whole property area)
10. Complete the following information for each drainage area identified in Project Information item 9. If there
are more than four drainage areas in the project, attach an additional sheet with the information for each area
provided in the same format as below.
Basin Information
Drain.< ge Area
3A i
Drainage Area 3B
Drainage A. -Yea 3C
Dramwve Area
f&_ 2
Receiving Stream Name
Smith Creek
Smith Creek
Smith Creek
Smith Creek
Stream Class *
C, Sw
C, Sw
C, Sw
C, Sw
Stream Index Number *
18-74-63
18-74-63
18-74-63
18-74-63
Total Drainage Area (sf)
213,213
756,099
542,656
12,529,107
On -site Drainage Area (sf)
213,213i
756,099
542,656
12,529,107
Off -site Drainage Area (sf)
0
0
0
0
Proposed Impervious Area** s
116,598
367,596
299,030
8,520,835
Impious Area** total
54.70
48.60 1
55.10
1 68.0
Impervious" Sarface Aiea.
Dmizwge Arrca
Drainage -krea
Draira a Area
Drainage Area
On -site Buildings/Lots (sf)
5,333
0
0
0
On -site Streets (sf)
13,746
103,565
0
0
On -site Parking (sf)
44,451
0
0
0
On -site Sidewalks (sf)
4,228
0
0
0
Other on -site (sf)
52
0
299,C60
0
Future (sf)
48,788
264,031
0
2,223,812
Off -site (sf)
n/a
n/a
n/a
n/a
Existing BLJA*** (sf)
n/a
n/a
n/a
6,297,023
Total (sf):
116,598
367,596
299,030
8,520,835
Stream Class and Index Number can be determined at: httpaortal.ncde,:;•.or !we? twg&s/csu/classificatio,zs
Form SWU-101 Version Oct. 31, 2013 Page 3 of 6

** Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
*** Report only that amount of existing BUA that will remain after development. Do not report any existing BUA that
is to be removed and which will be replaced by new BUA.
11. How was the off -site impervious area listed above determined? Provide documentation. There is no offsite
drainage area within the Phase 3A, Phase 3B, and Phase 3C areas.
Projects in Union County: Contact DEMLR Central Office staff to check if the project is located within a Threatened &
Endangered Species watershed that may be subject to more stringent stormwater requirements as per 1 SA NCAC 02B .0600.
V. SUPPLEMENT AND O&M FORMS
The applicable state stormwater management permit supplement and operation and maintenance (O&M) forms
must be submitted for each BMP specified for this project. The latest versions of the forms can be downloaded
from http://Portal.ncdenr.orL,/web/wo/ws/su/bmi)-manual.
VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Energy, Mineral and
Land Resources (DEMLR). A complete package includes all of the items listed below. A detailed application
instruction sheet and BMP checklists are available from
http://portal.nedenr.org/web/wg/ws/su/statesw/forms does. The complete application package should be
submitted to the appropriate DEMLR Office. (The appropriate office may be found by locating project on the
interactive online map atft://g2EWmcdenr.org/web/wg/ws/su/maRs.)
Please indicate that the following required information have been provided by initialing in the space provided
for each item. All original documents MUST be signed and initialed in blue ink. Download the latest versions
for each submitted application package fromho://Rortal.ncdenr.org/web/ffa/ws/­su/­statesw/fonns /Rortal.ncdenr.org;/web/wq/ws/su/statesw/forms does.
Initials
1. Original and one copy of the Stormwater Management Permit Application Form.
2. Original and one copy of the signed and notarized Deed Restrictions & Protective Covenants
Form. (if required as per Part VII below)
3. Original of the applicable Supplement Form(s) (sealed, signed and dated) and O&M
agreement(s) for each BMP.
4. Permit application processing fee of $505 payable to NCDENR. (For an Express review, refer to
http://www.envhelp.org/1ages/onestopexl2ress.html for information on the Express program
and the associated fees. Contact the appropriate regional office Express Permit Coordinator for
additional information and to schedule the required application meeting.)
5. A detailed narrative (one to two pages) describing the stormwater treatment/management for
6. A USGS map identifying the site location. If the receiving stream is reported as class SA or the
receiving stream drains to class SA waters within 1/2 mile of the site boundary, include the 1/z
mile radius on the map.
7. Sealed, signed and dated calculations (one copy).
8. Two sets of plans folded to 8.5" x 14" (sealed, signed, & dated), including:
a. Development/Project name.
b. Engineer and firm.
c. Location map with named streets and NCSR numbers.
d. Legend.
e. North arrow.
f. Scale.
g. Revision number and dates.
h. Identify all surface waters on the plans by delineating the normal pool elevation of
impounded structures, the banks of streams and rivers, the MHW or NHW line of tidal
waters, and any coastal wetlands landward of the MHW or NHW lines.
• Delineate the vegetated buffer landward from the normal pool elevation of impounded
structures, the banks of streams or rivers, and the MHW (or NHW) of tidal waters.
i. Dimensioned property/project boundary with bearings & distances.
j. Site Layout with all BUA identified and dimensioned.
k. Existing contours, proposed contours, spot elevations, finished floor elevations.
1. Details of roads, drainage features, collection systems, and stormwater control measures.
m. Wetlands delineated, or a note on the plans that none exist. (Must be delineated by a
qualified person. Provide documentation of qualifications and identify the person who
made the determination on the plans.
Form SWU-101 Version Oct. 31, 2013 Page 4 of 6

n. Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations.
o. Drainage areas delineated (included in the main set of plans, not as a separate document).
p. Vegetated buffers (where required).
Copy of any applicable soils report with the associated SHWT elevations (Please identify
elevations in addition to depths) as well as a map of the boring locations with the existing
elevations and boring logs. Include an 8.5"xll" copy of the NRCS County Soils map with the
project area clearly delineated. For projects with infiltration BMPs, the report should also
include the soil type, expected infiltration rate, and the method of determining the infiltration rate.
(Infiltration Devices submitted to WiRO: Schedule a site visit for DEMLR to verify the SHWT prior
to submittal, [phone].)
10. A copy of the most current property deed. Deed book: 817 Page No: 868
11. For corporations and limited liability corporations (LLC): Provide documentation from the NC
Secretary of State or other official documentation, which supports the titles and positions held
by the persons listed in Contact Information, item la, 2a, and/or 3a per 15A NCAC 21-1.1003(e).
The corporation or LLC must be listed as an active corporation in good standing with the NC
Secretary of State, otherwise the application will be returned.
http://www.secretarv.state.nc.us/Corvorations/CSearch.asDx
VII. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
For all subdivisions, outparcels, and future development, the appropriate property restrictions and protective
covenants are required to be recorded prior to the sale of any lot. If lot sizes vary significantly or the proposed
BUA allocations vary, a table listing each lot number, lot size, and the allowable built -upon area must be
provided as an attachment to the completed and notarized deed restriction form. The appropriate deed
restrictions and protective covenants forms can be downloaded from http://Rortal.ncdenr.org/web/Ir/state-
stArmwater-forms does. Download the latest versions for each submittal.
In the instances where the applicant is different than the property owner, it is the responsibility of the property
owner to sign the deed restrictions and protective covenants form while the applicant is responsible for ensuring
that the deed restrictions are recorded.
By the notarized signature(s) below, the permit holder(s) certify that the recorded property restrictions and
protective covenants for this project, if required, shall include all the items required in the permit and listed
on the forms available on the website, that the covenants will be binding on all parties and persons claiming
under them, that they will run with the land, that the required covenants cannot be changed or deleted
without concurrence from the NC DEMLR, and that they will be recorded prior to the sale of any lot.
VIII. CONSULTANT INFORMATION AND AUTHORIZATION
Applicant: Complete this section if you wish to designate authority to another individual and/or firm (such as a
consulting engineer and/or firm) so that they may provide information on your behalf for this project (such as
addressing requests for additional information).
Consulting Engineer:RICK BAKER, PE
Consulting Firm: TIMMONS GROUP
Mailing Address:5410 ` RINITY ROAD, STE 102
City:RALEIGH State:NC Zip:27607
Phone: (919 ) 866-4939 Fax: (919 ) 859-5663
Email:RICK.BAKER@TIMMONS. COM
IX PROPERTY OWNER AUTHORIZATION (if Contact Information, item 2 has been filled out, complete this
section)
I, (print or type name of person listed in Contact Information, item 2a) certify that I
own the property identified in this permit application, and thus give permission to (print or type name of person
listed in Contact Information, item 1a) DICK GRANSEUR with (print or type name of organization listed in
Contact Information, item 1a) NEW HANOVER COUNTY AIRPORT AUTHORITY to develop the
project as currently proposed. A copy of the lease agreement or pending property sales contract has been
provided with the submittal, which indicates the party responsible for the operation and maintenance of the
stormwater system.
Form SWU-101 Version Oct. 31, 2013 Page 5 of 6

As the legal property owner I acknowledge, understand, and agree by my signature below, that if my designated
agent (entity listed in Contact Information, item 1) dissolves their company and/or cancels or defaults on their
lease agreement, or pending sale, responsibility for compliance with the DEMLR Stormwater permit reverts back
to me, the property owner. As the property owner, it is my responsibility to notify DEMLR immediately and
submit a completed Name/Ownership Change Form within 30 days; otherwise I will be operating a stormwater
treatment facility without a valid permit. I understand that the operation of a stormwater treatment facility
without a valid permit is a violation of NC General Statue 143-215.1 and may result in appropriate enforcement
action including the assessment of civil penalties of up to $25,000 per day, pursuant to NCGS 143-215.6.
Signature:
I, na'(DVi 1-leneC', L • Yl e sn i t,l . a Notary Public for the State of
Dated '� " as 1
N G County of
RU tin QVCC , do hereby certify that LI(0�11 S� Ulf" C �� personally appeared
before me this A day of Ma h , r922 I and
.�ackkn1ow�le a the due execution off the application for
a stormwater permit. Witness my hand and official seal �,1 + ill R C.Gc 4 ,1�VI a
SEAL
My commission expires U--M- - a 0 a5
X. APPLICANT'S CERTIFICATION
I, (print or type name of person listed in Contact Information, item 1a) GRANSEUR DICK
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be recorded, and that the proposed project complies with the requirements of the
applicable stormwater rules under 15A NCAC
-.0 .r .211.1000 and any other applicable state stormwater requirements.
w
Signature:- Date: .3-2 -I;OZ1
0�SVI Ut a Notary Public for the State of N C, County of
do ltereby certify that N. F r(l=l f- 1�)i Gi,• personally appeared
before me this day of MG`f C: O c90a c and acknowledgcAla due execution of the application for
a stormwater permit. Witness my hand and official seal, 1-i� J'.
,`,����1111gN�I�11
c�
.. m
ram,✓ " /
e`.
`%
n`�`�
"IfI1111%0%
SEAL
I IY commission expires D 1A- ^ (9 ©Q
Form SWU-101 Version Oct. 31, 2013 Page 6 of 6

DEMLR USE ONI:Y
Date Received
Fee Paid
Permit Number
to 1 -7 94 aD
15
osos-YgL
Applicable Rules: ❑ Coastal SW -1995 ❑ Coastal SW - 2008 ❑ Ph II - Post Construction
(select all that apply) ❑ Non -Coastal SW- HQW/ORW Waters ❑ Universal Stormwater Management Plan
❑ Other WQ Mgmt Plan:
State of North Carolina
Department of Environment and Natural Resources
Division of Energy, Mineral and Land Resources C
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans
specifications, letters, operation and maintenance agreements, etc.):
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
2. Location of Project (street address):
0 AIRPORT BLVD
City:WILMINGTON County:NEW HANOVER Zip:28405
3. Directions to project (from nearest major intersection):
Southeast corner of the intersection of NC HWY 23 & AIRPORT BLVD
4. Latitude:34° 26' 7030" N Longitude:-77* 92' 1265" W of the main entrance to the project.
II. PERMIT INFORMATION:
1. a. Specify whether project is (check one): ❑New ®Modification ❑ Renewal w/ Modificationt
tRenewals with modifications also requires S➢V IA 02 - Renewal Application Form
b.If this application is being submitted as the result of a modification to an existing permit, list the existing
permit numberSW8 050547 , its issue date (if known)10/26/2011 , and the status of
construction: ®Not Started ❑Partially Completed* ❑ Completed* *provide a designer's certification
2. Specify the type of project (check one):
❑Low Density ®High Density ❑Drains to an Offsite Stormwater System ❑Other
3. If this application is being submitted as the result of a previously returned application or a letter from
DEMLR requesting a state stormwater management permit application, list the stormwater project number,
if assigned, NA and the previous name of the project, if different than currently
proposed, NA
4. a. Additional Project Requirements (check applicable blanks; information on required state permits can be
obtained by contacting the Customer Service Center at 1-877-623-6748):
❑CAMA Major ❑Sedimentation/Erosion Control: ac of Disturbed Area
❑NPDES Industrial Stormwater E404/401 Permit: Proposed Impacts Wetlands
b. If any of these permits have already been acquired please provide the Project Name, Project/Permit Number,
issue date and the type of each permit:N
5. Is the project located within 5 miles of a public airport? ❑No ®Yes
If yes, see S.L. 2012-200, Part VI. http://yortal.ncdenr.org/webAr/rules-and-re ations
Form SWU-101 Version Oct. 31, 2013 Page 1 of 6

III. CONTACT INFORMATION
1. a. Print Applicant / Signing Official's name and title (specifically the developer, property owner, lessee,
designated government official, individual, etc. who owns the project):
Applicant/Organization:NEW HANOVER COUNTY AIRPORT AUTHORITY
Signing Official & Title:DICK GRANSEUR, DIRECTOR
b. Contact information for person listed in item 1a above:
Street Address:1740 AIRPORT BLVD
City: WILMINGTON State:NC Zip:28405
Mailing Address (if applicable):SAME AS ABOVE
City:
State:
Zip:
Phone: (910 ) 341-4333 Fax: (910 ) 341-3465
Emai1:GDICK QOFLYILM.COM
c. Please check the appropriate box. The applicant listed above is:
❑ The property owner (Skip to Contact Information, item 3a)
® Lessee* (Attach a copy of the lease agreement and complete Contact Information, item 2a and 2b below)
❑ Purchaser* (Attach a copy of the pending sales agreement and complete Contact Information, item 2a and
2b below)
❑ Developer* (Complete Contact Information, item 2a and 2b below.)
2. a. Print Property Owners name and title below, if you are the lessee, purchaser or developer. (This is the
person who owns the property that the project is located on):
Property Owner/Organization:New Hanover County
Signing Official &
b. Contact information for person listed in item 2a above:
Street Address:
City:
Mailing Address (if applicable):
City:
Phone: ( )
Email:
State: Zip:,
State: Zip:
Fax: ( )
3. a. (Optional) Print the name and title of another contact such as the project's construction supervisor or other
person who can answer questions about the project:
Other Contact Person/Organization:MEREDITH W. RICE. JR / CIRCLE K STORES. INC
Signing Official & Title:VICE PRESIDENT
b. Contact information for person listed in item 3a above:
Mailing Address:1100 SITUS COURT, STE 100
City:RALEIGH State:NC Zip:27606
Phone: L919 ) 744-6700 Fax: (NONE ) NONE
Email:WRICE@CIRCL EK.COM
4. Local jurisdiction for building permits: NEW HANOVER COUNTY
Point of Contact:INSPECTIONS DEPT Phone #: (910 ) 798-7308
Form SWU-101 Version Oct. 31, 2013 Page 2 of 6

IV. PROJECT INFORMATION
1. In the space provided below, briefly summarize how the stormwater runoff will be treated.
2. a. If claiming vested rights, identify the supporting documents provided and the date the
❑ Approval of a Site Specific Development Plan or PUD Approval Date: 24 NOV 2004
❑ Valid Building Permit Issued Date: 26 OCT 2004
® Other: ILM Stormwater Master Plan Date: 24 NOV 2004
b.If claiming vested rights, identify the regulation(s) the project has been designed in accordance with:
® Coastal SW -1995 ❑ Ph 11- Post Construction
3. Stormwater runoff from this project drains to the Cape Fear River basin.
4. Total Property Area: 322.3 acres
5. Total Coastal Wetlands Area: acres
6. Total Surface Water Area: 0 acres
7. Total Property Area (4) - Total Coastal Wetlands Area (5) - Total Surface Water Area (6) = Total Project
Area+:322.3 acres
+ Total project area shall be calculated to exclude the following: the normal pool of impounded structures, the area
between the banks of streams and rivers, the area below the Normal High Water (NHK9 line or Mean High Water
(MHM line, and coastal wetlands landward from the NHW (or MHIline. The resultant project area is used to
calculate overall percent built upon area (B ). Non -coastal wetlands landward of the NHW (or MHM line may
be included in the total project area.
8. Project percent of impervious area: (Total Impervious Area / Total Project Area) X 100 = 66.27 %
9. How many drainage areas does the project have?4 (For high density, count 1 for each proposed engineered
stormwater BMP. For low density and other projects, use 1 for the whole property area)
10. Complete the following information for each drainage area identified in Project Information item 9. If there
are more than four drainage areas in the project, attach an additional sheet with the information for each area
provided in the same format as below.
Basin Information
Dwthu:ge Area
3
Drainage nrea 3a
1 Drainage Area 3C
DrahuflArm —
Receiving Stream Name
Stream Class *
Smith Creek
Smith Creek
Smith Creek
Smith Creek
C, Sw
C, Sw
C, Sw
C, Sw
Stream Index Number *
18-74-63
18-74-63
18-74-63
18-74-63
Total Draina a Area (sf)
213,213
756,099
542,656
12,529,107
On -site Drainage Area (sf)
213,213
756,099
542,656
12,529,107
Off -site Drainage Area (sf)
0
0
0
0
Proposed Impervious Area** s
116,598
1367,596
299,030
8,520,835
% Im ervious Area** total
54.70
1 48.60
1 55.10
1 68.0
In ervlous" Surface Area
Drainage Area
Dranra,pe Area
Dram ;e Area_
Draimp area
On -site Buildings/Lots (sf)
5,333
0
0
0
On -site Streets A
13,746
103,565
0
0
On -site Parking (sf)
44,451
0
0
0
On -site Sidewalks (sf)
1 4,228
0
0
0
Other on -site (sf)
52
0
299,030
0
Future (sf)
48,788
264,031
0
2,223,812
Off -site (sf)
n/a
n/a
n/a
n/a
Existing BUA*** (sf)
n/a
n/a
n/a
6,297,023
Total (sf):
116,598
367,596
299,030
1 8,520,835
* Stream Class and Index Number can be determined at: http:/&ortal.izcdezzr.or /web/wq/ps/csu/c.assiftcations
Form SWU-101 Version Oct. 31, 2013 Page 3 of 6

Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
'Report only that amount of existing BUA that will remain after development. Do not report any existing BUA that
is to be removed and which will be replaced by new BUA.
11. How was the off -site impervious area listed above determined? Provide documentation. There is no offsite
drainage area within the Phase 3A, Phase 3B, and Phase 3C areas.
Proiects in Union County: Contact DEMLR Central Office staff to check if the project is located within a Threatened &
Endangered Species watershed that may be subject to more stringent stormwater requirements aspen I5A NCAC 02B .0600.
V. SUPPLEMENT AND O&M FORMS
The applicable state stormwater management permit supplement and operation and maintenance (O&M) forms
must be submitted for each BMP specified for this project. The latest versions of the forms can be downloaded
fromhttv://t)ortal.nedenr.org/web/wa/ws/su/bmiD-manual.
VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Energy, Mineral and
Land Resources (DEMLR). A complete package includes all of the items listed below. A detailed application
instruction sheet and BMP checklists are available from
bM://12ortal.ncdenr.org/web/wq/ws/su/­statesw/forms docs. The complete application package should be
submitted to the appropriate DEMLR Office. (The appropriate office may be found by locating project on the
interactive online map at ha://Portal.ncdenr.org/web/wq/ws/su/maps.)
Please indicate that the following required information have been provided by initialing in the space provided
for each item. All original documents MUST be signed and initialed in blue ink. Download the latest versions
for each submitted application package fromht!p://12ortal.ncdenr.org/web/wq/ws/su/statesw/forms docs.
Initials
1. Original and one copy of the Stormwater Management Permit Application Form.
2. Original and one copy of the signed and notarized Deed Restrictions & Protective Covenants
Form. (if required as per Part VII below)
3. Original of the applicable Supplement Form(s) (sealed, signed and dated) and O&M
agreement(s) for each BMP.
4. Permit application processing fee of $505 payable to NCDENR. (For an Express review, refer to
h=://www.envheIg.org/pages/onestoRgxpress.html for information on the Express program
and the associated fees. Contact the appropriate regional office Express Permit Coordinator for
additional information and to schedule the required application meeting.)
5. A detailed narrative (one to two pages) describing the stormwater treatment/management for
6. A USGS map identifying the site location. If the receiving stream is reported as class SA or the
receiving stream drains to class SA waters within 1h mile of the site boundary, include the 1/2
mile radius on the map.
7. Sealed, signed and dated calculations (one copy).
8. Two sets of plans folded to 8.5" x 14" (sealed, signed, & dated), including:
a. Development/Project name.
b. Engineer and firm.
c. Location map with named streets and NCSR numbers.
d. Legend.
e. North arrow.
f. Scale.
g. Revision number and dates.
h. Identify all surface waters on the plans by delineating the normal pool elevation of
impounded structures, the banks of streams and rivers, the MHW or NHW line of tidal
waters, and any coastal wetlands landward of the MHW or NHW lines.
• Delineate the vegetated buffer landward from the normal pool elevation of impounded
structures, the barks of streams or rivers, and the MHW (or NHIAI) of tidal waters.
i. Dimensioned property/project boundary with bearings & distances.
j. Site Layout with all BUA identified and dimensioned.
k. Existing contours, proposed contours, spot elevations, finished floor elevations.
1. Details of roads, drainage features, collection systems, and stormwater control measures.
m. Wetlands delineated, or a note on the plans that none exist. (Must be delineated by a
qualified person. Provide documentation of qualifications and identify the person who
made the determination on the plans.
Form SWU-101 Version Oct. 31, 2013 Page 4 of 6

n. Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations.
o. Drainage areas delineated (included in the main set of plans, not as a separate document).
p. Vegetated buffers (where required).
Copy of any applicable soils report with the associated SHWT elevations (Please identify
elevations in addition to depths) as well as a map of the boring locations with the existing
elevations and boring logs. Include an 8.5"x11" copy of the NRCS County Soils map with the
project area clearly delineated. For projects with infiltration BMPs, the report should also
include the soil type, expected infiltration rate, and the method of determining the infiltration rate.
(Infiltration Devices submitted to WiRO: Schedule a site visit for DEMLR to verify the SHWT prior
to submittal, [phone].)
10. A copy of the most current property deed. Deed book: 817 Page No: 868
11. For corporations and limited liability corporations (LLC): Provide documentation from the NC
Secretary of State or other official documentation, which supports the titles and positions held
by the persons listed in Contact Information, item la, 2a, and/or 3a per 15A NCAC 2H.1003(e)
The corporation or LLC must be listed as an active corporation in good standing with the NC
Secretary of State, otherwise the application will be returned.
http://www.secretarv.state.nc.us/Corvorations/CSearc-h.asDx
VII. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
For all subdivisions, outparcels, and future development, the appropriate property restrictions and protective
covenants are required to be recorded prior to the sale of any lot. If lot sizes vary significantly or the proposed
BUA allocations vary, a table listing each lot number, lot size, and the allowable built -upon area must be
provided as an attachment to the completed and notarized deed restriction form. The appropriate deed
restrictions and protective covenants forms can be downloaded from http://2ortal.ncdenr.org/web/lr/state-
stormwater-forms does. Download the latest versions for each submittal.
In the instances where the applicant is different than the property owner, it is the responsibility of the property
owner to sign the deed restrictions and protective covenants form while the applicant is responsible for ensuring
that the deed restrictions are recorded.
By the notarized signature(s) below, the permit holder(s) certify that the recorded property restrictions and
protective covenants for this project, if required, shall include all the items required in the permit and listed
on the forms available on the website, that the covenants will be binding on all parties and persons claiming
under them, that they will run with the land, that the required covenants cannot be changed or deleted
without concurrence from the NC DEMLR, and that they will be recorded prior to the sale of any lot.
VIII. CONSULTANT INFORMATION AND AUTHORIZATION
Applicant: Complete this section if you wish to designate authority to another individual and/or firm (such as a
consulting engineer and/or firm) so that they may provide information on your behalf for this project (such as
addressing requests for additional information).
Consulting Engineer:RICK BAKER, PE
Consulting Firm: TIMMONS GROUP
Mailing Address:5410 TRINITY ROAD, STE 102
City:RALEIGH State:NC Zip:27607
Phone: (919 ) 866-4939 Fax: (919 ) 859-5663
Email:RICK.BAKER®TIMMONS.COM
IX. PROPERTY OWNER AUTHORIZATION (if Contact Information, item 2 has been filled out, complete this
section)
I, (print or type name of person listed in Contact Information, item 2a) certify that I
own the property identified in this permit application, and thus give permission to (print or type name of person
listed in Contact Information, item 1a) DICK GRANSEUR with (print or type name of organization listed in
Contact Information., item 1a) NEW HANOVER COUNTY AIRPORT AUTHORITY to develop the
project as currently proposed. A copy of the lease agreement or pending property sales contract has been
provided with the submittal, which indicates the party responsible for the operation and maintenance of the
stormwater system.
Form SWU-101 Version Oct. 31, 2013 Page 5 of 6

As the legal property owner I acknowledge, understand, and agree by my signature below, that if my designated
agent (entity listed in Contact Information, item 1) dissolves their company and/or cancels or defaults on their
lease agreement, or pending sale, responsibility for compliance with the DEMLR Stormwater permit reverts back
to me, the property owner. As the property owner, it is my responsibility to notify DEMLR immediately and
submit a completed Name/Ownership Change Form within 30 days; otherwise I will be operating a stormwater
treatment facility without a valid permit. I understand that the operation of a stormwater treatment facility
without a valid permit is a violation of NC General Statue 143-215.1 and may result in appropriate enforcement
action including the assessment of civil penalties of up to $25,000 per day, pursuant to NCGS 143-215.6.
Signature: Date. A " 02,1
I,trr=r i 1�; 1 1C C 1 �' `�: 's�� a Not Public for the State of `
` �3' .County of
V 1 G i ; `� , do hereby certify that . �� a" �:tn -s `. i personally appeared
before me this 7� day of 4 �� i' �%i and acknowledge the due execution of the application for
a stormwater permit. Witness my hand and official seal;
'01111111111"
0
t���//111111111�,,
erg,
X. APPLICANT'S CERTIFICATION
SEAL
;�.
My commission expires �. �': -- - 6)C;
I, (print or type name of person listed in Contact Information, item 1a) GRANSELIR DICK
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be recorded, and that the proposed project complies with the requirements of the
applicable stormwater rules under 15A NCACI.1000 and any other applicable state stormwater requirements.
Signature:
Date: 3 - `� -.;o'z!
Ly a Notary Public for the State of i ; County of
do hereby certify that _ i.� , , - personally appeared
before me this_ day of and acknowled" due execution of the application for
a stormwater permit. Witness my hand and official seal, _Ji ii- ' ti __..:�_ 0 +
����11NO111i►�'�♦♦
SEAL
My commission expires
Form SWU-101 Version Oct. 31, 2013 Page 6 of 6

TRANSMITTAL
I -gil Srak:
j
15, Cl rl,ez-ville Strcu Corae,ia. GI, J0531
.i V 7 ()ice: or 678-2( --"690 FiL-,.,: 6
I"() Attention: Georgette Scott
NC Division of Environmental Quality Land Resources
127 Cardinal Drive Ext
Wilmington, NC 28405
c4smith
G"GINEE"ING, LLC
DATE: NOVEMBER 20,2020
ITEM JOB NAME JOB NUMBER
NCDEQ Minor Mod A.ero Center Wilmington 2020-274-01
DATE DESCRIPTION
11/13/2020 Stormwater Permitting Fottn 7: Minor Modification SW8 050547
11/13/2020 Narrative with Impervious Calculations
11/13/2020 Phase II Drainage Area Revised Boundary (from previous submit)
11/13/2020 Full Size Plan Sets (Aern FBO and Fuel Farm)
APR 2 0 2021
lly-_____ -
QUANTITY
2
2
2
2
155 C!afxesv4,le Stz-eet
Post OfTce Box 331
Corne'ia, GA 3053:
Main Lire: 706-894-233 '1
Cell: 706-244-8180
Atlanta Area Phone: [phone]
Fax: [phone]
Email:[e-mail]

C4SMith
I
November 20, 2020
NC Division of Environmental Quality
Land Resources
127 Cardinal Drive Ext.
Wilmington, NC 28405
RE: North GA Site Development for Aero Center Wilmington Minor Mod to SW8 050547
To whom it may concern:
The Wilmington International Airport is preparing a lease site for a FBO for Aero Center Wilmington
and associated hangars in the North General Aviation site north of Hall Drive/Customs facility, east of
Trask Drive and south of the Airport Snow Maintenance Facility. This project will remove existing
pavement and construct the new development.
Currently, the site drains toward Acorn Branch. The new development will collect and direct
stormwater runoff into an existing pipeline along the eastern edge of Trask Drive; the existing drainage
system that conveys stormwater to Extended Dry Detention Basin #1 and the associated pre-treatment
swales (Airport's existing Regional BMPs under Stormwater Permit No. SW8 050547). The basin and
pre-treatment swales have been previously sized and permitted for future allocations. This
development will utilize 48,658 square feet of that future BUA allocation.
Based on the approved revision.to the permit SW8 050547, this project's proposed drainage area is
within the 'overall basin map'. Sub -basin areas into the existing structures are being modified slightly
to accommodate the new structures.
Attached is a list of the project's drainage areas containing existing and proposed built -upon area.
These areas are shown on Exhibit B.
Exhibit Al from a previous revision is included that was revised to account for this development.
Exhibit A is from the last permit revision approved 10/5/2018 showing the existing basins.
We have also attached a copy of the previous permit revision for your reference.
EC
155 Clarkesville Street
APR 0 ZUZt Post Office Box 331
Cornelia, GA 30531
Main Line: 706-894-2331
BY Cell: 706-244-8180
Atlanta Area Phone: [phone]
Fax:[phone]
[e-mail]

November 20, 2020
NC Division of Environmental Quality
North GA Site Development for Aero Center Wilmington Minor Mod to SW8 050547
Page 2
TBI No. 3301-1602 & 3301-1703
Built -Upon Area Total to be directed to the existing approved BMPs for future allocations
Existing Previously Permitted
Proposed Revisions to
Previously Permitted
Total Built
Upon Area to
be added to
revision
Structure
Drainage Area
s
Built Upon Area
s
Drainage Area
s
Built -Upon
Area s
TL-1
37,631
29,011
37 631
29,011
0
TL-2
24,396
6,305
27,243
11,847
5,542
B-4
29,404
5,095
29,404
5,095
0
B-5
139,958
26 178
152,766
49,545
23,367
B-6
246,951
103,429
273,724
123 178
19,749
Total
478 340
170,018
478,340
218 676
48,658
Notes:
Drainage Basins TL-1 & B-4 are unchanged from previous permits
Drainage Basin B-6 for the fuel. farm has increased slightly in size, however proposed overall drainage
area is unchanged
Exhibit A1: Previous Revisions to Drainage and Built -Upon Areas for Approved Minor Modification —
Addition of FBO #2 Area
Exhibit A:Exhibit from previous permit revisions for Existing Drainage Basins
Exhibit B: Proposed Revisions to Drainage and Built -Upon Areas
Should you have any questions, please contact me at [phone].
Sincerely,
(4 Z *7-1 �W
Jason M. Smith, PE
APR 2 0 2021
BY_-

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WILMINGTON INTERNAIONAL AIRPORT
WILMINGTGN, NORTH CAROLINA
NORTH GENERAL AVIATION HANGAR TAXILANE ` ALBE T &.13RiGHT
AND 4810 SHELLEY DRIVE
CORPORATE HANGAR COMPLEX WILMINGTON, NC 28405
PHONE: [phone]
POST DRAINAGE AREAS NO LICENSE NO. 0-0713
AND IMPERVIOUS AREAS
TL-1, TL-2, & XNE 20. 2U16 A
- B-4 are to be From SW8 050547 Plan Revision
revised dated June 29 2016

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0000
5410 Trinity Road
TIMMivNS GRJOAaP Suite102
Tc 1�t,".SK :,•_ s. Raleigh, NC27607
TRANSMITTAL,
NCDEQ — Christine Hail
TO:
Stormwater Department
127 Cardinal Drive Extension
Wilmington, NC 28405
P 919.866.4951
F 919.859.5663
wMrw finrMwia�.aon
JECIEIVI
I APR 13 2021
Date: 419/21 Job#: 37630.054
Circle K — NTI Airport Blvd Wilmington —
Project: NC.115
Reference: Submittal #3
Copies Sent To: Garrett Zorda
COPIES I DATE I NUMBER DESCRIPTION
1 04/09/2021 1 1 1 Signed and sealed Technical Justification / Comment Response
THESE ITEMS ARE TRANSMITTED:
If enclosures are not as noted, please notify us at once.
COMMENTS:
Internal exhibits used during design also in CD for reference
Thank You,
Brian W. Downs
Senior Project Manager
Timmons Group
CIVIL ENGINEERING I ENVIRONMENTAL I SURVEYING 1 GIS I LANDSCAPE ARCHITECTURE I CONSTRUCTION SERVICES

T echnical Justification
Circle K — NTI Airport Blvd Wilmington — NC.115
Airport Boulevard
Wilmington, NC 28405
(PID: R04200-001-025-F00)
Prepared by:
TIMMONS GROUP Weelve
Project #: AIR i j
37630.054 AV,
Date:
4/09/2021
eeeeeep°oN
y
TIMMONS GROUP
YOUR VISION ACHIEVED THR04t'.r; s..".'�5.

e0e000.
%
5410 Trinity Road P 919.866.4951
T i M M O N S GROUP Suite 102 F 919.859.5663
�7 Raleigh, NC 27607
To:
Garrett Zorda, Environmental Engineer
NCDEQ, Wilmington Regional Office
Date:
March 29, 2021
Project Name:
Circle K — NTI Airport Blvd Wilmington — NC115
Project number:
37630.054
Project Contact:
Brian Downs
Phone:
919-866-4504
E-Mail:
[e-mail]
Please see our response to your comments in red below each comment.
Garrett Zorda, Environmental Engineer I email: [e-mail]
15A NCAC 02H.1003(6) and the 2004 approved Stormwater Master Plan document: The
response to Items #1.b and 1.c of the previous request for additional information indicate
that the dry detention basins and grassed swales are designed to provide the minimal
separation to the seasonal high water table. The resulting design of the two dry
detention basins and two grassed swales, however, still set these devices between 4.5
feet and 6.75 feet below the seasonal high water table. These two new dry detention
basins and grassed swales must either meet the requirements in the previously
approved agreement from 2004 or demonstrate they are an equal or better variation
under the 2017 rules.
Response: The approved 2004 Stormwater Master Plan provided a technical framework
for processing future NCDENR Stormwater permits for individual development projects
on airport property. The document provided two stormwater management concepts for
the west side of the airport. A "centralized' and a "distributed" concept. Previous Master
stormwater improvements to -date have relied upon the initial 2005 Centralized
stormwater concept with the primary solution being the existing Extended Dry Detention
basin which lies southwest of the main circular parking area. Through several updates,
the ILM Master Planned stormwater orphaned the Phase 3 area for it to be inlcuded in a
stormwater solution at a later date.
After a deep dive into the site constrains, we understand why this area was not
approached head-on until this time. Based upon site constraints, to be better detailed
later, the "distributed" concept was selected to provide a permanent stormwater solution
to as much of the 34.71-acre Phase 3 drainage area as possible. This solution was best
suited for the remaining area because it can be more readily phased than the centralized
concept. This "decentralized" approach required new SHWT tests which revealed an
issue that is likely prevalent elsewhere on -site namely, a high SHWT which is between
8"-12" below existing grade.
Ei-IGINEERING I DESIGN I TECHNOLOGY

Additional consideration was given to current MDC regulations. We utilized the latest
available version for each SCM type on the NCDEQ website for our analysis. Both
originally and within this document.
As all parties are aware, this is a unique site that has established its own set of
requirements that does not necessarily follow the standard rules and guidelines of the
DEQ Stormwater program. Knowing this and throughout our design, we have consulted
with no less than 7 design professionals (6 with PE licensure in NC) within our company,
all with extensive stormwater design experience in all regions of NC including the
Coastal Plain to make sure we are providing stormwater treatment to meet the intent of
the stormwater rules and follow closely the 2004 stormwater Master Plan for ILM.
A concise general narrative is difficult due to the project complexity however, we are
providing the necessary information to respond to your comments but in as concise
manner as possible.
1) For reference, a concept "distributed" design was included in the 2004 Stormwater
Master Plan as shown on sheet PR1.2.
a) The "distributed" stormwater concept involves using multiple smaller
extended dry detention basins throughout the drainage area. Based on the
idea that stormwater is detained and treated locally at each project site and
then conveyed off airport property.
2) Our site falls within the western portion of the airport property and retains much of
the original infrastructure which dates back to World War II era construction. The
approved 2004 Stormwater Master Plan categorized this area by stating: the system
of open channels, culverts, and smaller closed systems which drain this area is
generally in poor condition and of limited capacity. This area remains sparsely
developed and requires significant stormwater infrastructure improvements to
accommodate future development.
3) Our site currently contains 1.84 acres of impervious surface (roads) which is not
currently being treated by any SCMs.
4) Our project area includes two offsite discharge points:
a) Our project site falls entirely within an area specified for "Airport Business
Park Development / Redevelopment" per 2004 sheet PR1.2.
b) Drainage areas include part of Sub -Basin 1, all of Sub -Basin 2, and part of
Sub -Basin 3 as outlined in Section 3 of the 2004 Stormwater Master Plan.
These areas are illustrated on sheets EX1.0 and EX1.4 of the 2004
Stormwater Master Plan.
c) This "decentralized" approach favors reintroducing runoff from impervious
surfaces into the natural environment as close to the impervious surfaces as
possible in line with recent trends in stormwater management.
5) "High Density" projects are projects involving more than 30 percent built -upon area.
Stormwater controls need to be implemented as high density development occurs
involving a net increase in built -upon area.

a) Phase 3A will now exceed the 30% BUA upper limit for "Low Density" with the
proposed C-Store project.
b) However, Phase 3B will currently remain under the 30% BUA upper limit for
"Low Density" and is being undertaken at this time to proactively provide a
means of treating stormwater prior to future high density development.
6) Primary SCM selection criteria included: standing water near airport, maintaining
Jurisdictional and isolated wetlands, stream channels, and riparian buffers.
a) During development of the approved 2004 Stormwater Master Plan, the
wildlife hazard issue (standing water near airport) was recognized as a key
issue in development of the Plan. It was considered prudent to review wildlife
concerns from a local, site specific perspective as well as in the nation-wide
context of the FAA Wildlife Advisory Circular No. 150/5200-33.
b) USACE Jurisdictional wetlands and riparian buffers occur immediately
downstream of Phase 3B per our 2020 delineation.
c) Downstream of Phase 3A is a culvert which is outside of our Environmental
mapping scope since if falls off the ILM property. However, the National
Wetlands Inventory map illustrates a 13.77 acres Freshwater Forested/Shrub
wetland, classified as PFO1/2F, immediately downstream of the Phase 3A
culvert.
7) Secondary SCM selection concerns included: maintenance and construction costs
for ILM Airport which is a public entity.
a) This selection criteria are supported by the 2004 Stormwater Master plan
which includes funding resources as a criteria within Section XIII.
8) Our scope it is to "complete" Stormwater Treatment for as much of the Phase 3
drainage area as possible. Currently most of the drainage area is undeveloped. Our
scope also includes the Circle K development.
(a) Most of the remainder ILM Business Park land within the drainage areas will
not be built -out at this time.
(b) Future construction is expected to happen in a number of different phases
because our drainage area includes at least 3 additional Master Planned
parcels.
(c) Before full build -out occurs, there will be an indefinite period of time of high
sediment input into the SCMs during inactivity. Supplemented by times of
even greater sediment input into the SCMs during the future phased
construction.
(d) SCM selection must factor in these periods of high sedimentation to reduce
the risk of shortenina the functional lifespan of an SCM.
9) Our site contains topographic challenges due to its proximity to the coast.
(a) For Phase 3A:
(i) The Circle K will primarily drain by sheet flow across vegetated surfaces
into the SCM.
(ii) Stormwater will be conveyed under roadways by culvert pipes.
1. Required cover is needed to pass water under the roads. Roads are
required for interconnectivity of the individual lots.

(iii) The water then passes through the pre-treatment Grassed Swale at
0.10% and then through the Extended Dry Detention basin at 1.0%.
(iv) Ultimately crossing under N. 231d Street via a 24" RCP culvert pipe with
an upstream invert of 14.00'.
(v) All told, the water for Phase 3A covers--1,000+ LF with a net 10' of
elevation change for an average of 1 % slope in a perfect world without
additional constraints.
1. This ideal 1 % slope is not possible and the real world constraints will
be detailed later.
(b) For Phase 3B:
(i) The restricting elevation is the outlet of an 18" RCP pipe which crosses
under Airport Blvd and outlets at 19.05'.
(ii) The water will then be conveyed by a combination of ditches and pipes.
1. Culvert pipes with required cover is needed to pass water under the
future loop road. Roads are required for interconnectivity of the
individual lots.
(iii) The water then passes through the pre-treatment Grassed Swale at
0.20% and then through the Extended Dry Detention basin.
(iv) An ultimate outlet is to a buffered intermittent stream at 12.50'.
(v) All told the water for Phase 3B covers —950+ LF, south of Airport Blvd,
with a net 6.55' of elevation change for an average of 0.69% slope in a
perfect world without additional constraints.
1. This ideal 0.69% slope is not possible and the real world constraints
will be detailed later.
(c) We evaluated connecting to the existing SCMs via a swale and/or pipes
under the "Centralized" concept. However, this approach presented
numerous challenges. Namely a concern about backwater issues, all the way
to the Circle K leased parcel and dewatering Jurisdictional wetlands.
(i) An abundance of INTERNAL exhibits are included with the submittal
showing the various configuration we designed, to various levels, before
submitting this design. More exist but the additional ones are largely
redundant.
10) Our site has numerous physical constraints (topography and wetlands) and it has
proven especially challenging to settle on an appropriate SCM type. In this case, we
believe it is necessary to modify the standard SCM designs, due to site
characteristics, to provide the required level of permanent stormwater treatment.
More specifics on proposed modifications are provided below in #19, #20, and #21.
a. The purpose of the 2004 "Stormwater Master Plan" alternative design document was
to preserve water quality standards while also ensuring the constructed practice did
not attract wildlife that could become a hazard to air traffic. This agreement was later
supported by G.S. 143-214.7(c3), which was added by Session Law 2012-200, and
confirms that the Division does not require the use of wet ponds or other SCMs that
promote standing water on or near public airports. While the "Stormwater Master

Plan" recommends the use of Extended Dry Detention Basins combined with
grassed swales, it does not "limit or restrict the airport or its current or prospective
tenants with respect to pursuing alternative or modified stormwater management
solutions in various locations." Since the inception of the "Stormwater Master Plan",
other primary SCM options that do not retain a permanent pool and/or promote
standing water have become available and approved by the Division (i.e. sand filters,
underground infiltration trenches, proprietary systems such as ADS BayFilters, etc.).
Please confirm if any of the more recent SCM options were considered to treat the
runoff from the proposed development. Please also provide additional justification
that the current design of a combination of grassed swales and dry ponds meets all
of the requirements of the "Stormwater Master Plan" or that they are an equal or
better variation to these other primary SCMs.
Response:
In our evaluation of stormwater treatment, we reviewed all 2004 Stormwater Master
Plan and current MDC options extensively to determine what SCM or combination of
SCM's will provide treatment to meet the 2004 Master Plan or 2017 DEQ rules.
Below is our evaluation of each SCM.
2004 and 2017 SCM devices were considered:
1) Bioretention with, or without, underdrain:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #1: Minimum of 2' separation required above the SHWT.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM Selection.
d) The 2004 Master Plan excluded "bioretention areas" from consideration at ILM based
upon the expectation they would create conditions that attract wildlife species which are
hazardous to aviation.
e) Not Selected due to criteria listed above mainly HIGH wildlife habitat and 2004 plan
excluding bioretention.
2) Stormwater Wetland:
a) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The 2004 Master Plan excluded "extended detention wetlands" and "pocket wetlands"
from consideration at ILM based upon the expectation they would create conditions that
attract wildlife species which are hazardous to aviation.
c) Not Selected due to criteria listed above - HIGH wildlife habitat and 2004 plan excluding
constructed wetlands.

3) Wet pond:
a) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The 2004 Master Plan strongly advocates avoidance of wet detention basins and
recommends the use of extended dry detention basins for stormwater management.
c) Not Selected due to criteria listed above - HIGH wildlife habitat and 2004 plan avoidance
of wet ponds bioretention.
4) Permeable Pavement:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #2: Minimum of 2' separation required above the SHWT for infiltration
pavement systems; Minimum 1' for detention pavement systems.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) The 2017 MDC Section E-4 Airports Table 1 states: It is best implemented in areas that
receive relatively infrequent traffic.
i) However, the areas to be paved surround the primary Airport entrance and will
receive frequent traffic.
d) Not Selected due to minimal amount of pavement proposed and SHWT elevation.
5) Infiltration Device:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #2: Minimum of 2' separation required above the SHWT.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) The 2004 Master Plan excluded infiltration devices" from consideration at ILM based
upon the expectation they would create conditions that attract wildlife species which are
hazardous to aviation.
d) Not Selected - 2004 Master Plan excluding infiltration devices.
6) Dry Pond (standard):
a) Listed as "Y" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #1: Minimum of 6" separation required above the SHWT.
ii) Utilizing a shallower, and wider, Dry Detention basin is not feasible due to the SHWT
being 8" or 12" below existing surface. Such an approach would require raising the
vast majority of the drainage areas with fill material. Which would have a substantial
impact on the existing roadway network and would require a high cost for the needed
amount of fill material.

c) The 2017 MDC Section E-4 Airports Table 1 states: Dry Detention basins do pond water
for more than 12 hours after storm events but still may be desired to treat a large
drainage area.
d) See Proposed SCM Solution below
7) Sand Filter (Open Bottom/Open Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be two feet for open -bottom
designs.
c) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even.
d) An open top device would require surface flow into the device. Sand Filters require 1.5'
(18" of filter media). Presenting a ponding depth issue.
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23'd at 14.00' elevation.
(a) Effectively 1' of elevation would be left for treatment storage atop of the open
top sand filter. Not accounting for a height reduction for emergency overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 313:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlet at 14.80' and
EW200 outlets at 12.80' for an ultimate tie-in at 12.50'.
(a) Effectively 0.8' of elevation would be left for treatment storage atop of the
open top sand filter. Not accounting for a height reduction for overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
iii) In areas of low relief, the hydraulic head necessary for some devices to function
properly may not be available.

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e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 313:
(a) Total of 17.36 acres of drainage area.
(i) Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.
f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do not mitigate the peak flow from a storm event. Sand Filters
require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to SHWT and possible saturation of sand media, drainage area size,
elevation requirement from flow into SCM to invert out and costs of SCM and adding
stormwater detention.
8) Sand Filter (Closed Bottom/Open Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
i) Phase 3A:
(1) High sediment input can significantly reduce the longevity of sand filters.
(2) Currently proposed as —32% impervious.

(3) Phase 3A has 1.07 acres of allocated future impervious. With little, to no area, to
add erosion control measures upstream of the SCM before sediment input would
enter the sand filter.
ii) Phase 3B:
(1) Sand filters function much better when the drainage area is highly built -upon
because this will greatly reduce the amount of fines that reach the sand filter and
potentially cause clogging.
(2) Currently proposed as —13.7% impervious. Pervious is upstream of SCM and
cannot be graded away from SCM.
(3) Phase 3B has 6.05 acres of allocated future impervious. With few areas to add
erosion control measures upstream of the SCM before sediment input would
enter the sand filter.
b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be one foot for closed bottom
designs. Exceptions to the one foot SHWT separation may be made if the applicant
provides documentation that the design will neither float nor drain the water table.
c) Culvert pipe under N. 23"d Street is currently undersized. Backwater into a Phase 3A
sand filter would likely occur prior to water overtopping the road. Extending the period of
time the filter media is surcharged.
d) Sand Filters require 1.5' (18" of filter media).
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23'd at 14.00' elevation.
(a) Effectively 1' of elevation would be left for treatment storage atop of the open
top sand filter. Not accounting for a height reduction for overland overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 3B:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(a) Effectively 0.8' of elevation would be left for treatment storage atop of the
open top sand filter. Not accounting for a height reduction for overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.

iii) In areas of low relief, the hydraulic head necessary for some devices to function
properly may not be available.
e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 313:
(a) Total of 17.36 acres of drainage area. Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.
f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even. Closed Bottom
Sand Filters require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out and costs of SCM and adding stormwater detention. Costs rise further due to
anti -floatation measures required.
9) Sand Filter (Closed Bottom/Closed Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
i) Phase 3A:
(1) High sediment input can significantly reduce the longevity of sand filters.
(2) Currently proposed as —32% impervious.
(3) Phase 3A has 1.07 acres of allocated future impervious. With little, to no area, to
add erosion control measures upstream of the SCM before sediment input would
enter the sand filter.
ii) Phase 313:
(1) Sand filters function much better when the drainage area is highly built -upon
because this will greatly reduce the amount of fines that reach the sand filter and
potentially cause clogging.
(2) Currently proposed as —13.7% impervious. Pervious is upstream of SCM and
cannot be graded away from SCM.
(3) Phase 3B has 6.05 acres of allocated future impervious. With few areas to add
erosion control measures upstream of the SCM before sediment input would
enter the sand filter.

b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be one foot for closed bottom
designs. Exceptions to the one foot SHWT separation may be made if the applicant
provides documentation that the design will neither float nor drain the water table.
c) Culvert pipe under N. 23rd Street is currently undersized. Backwater into the sand filter
would likely occur prior to water overtopping the road. Extending the period of time the
filter media is surcharged.
d) Sand Filters require 1.5' (18" of filter media). MDC Recommendation #2 calls for access
the inside of the box. Based on real life experience the inside of a closed bottom sand
filter should be no less than 5' in height. (Preferrable 6.5% but we'll use 5' for this
description.) The 5' height allows enough space, above the media, for an OSHA
compliant confined space entry. Which is necessary to remove V or 2" of sand for
remediation. This removal is a manual process.
i) In areas of low relief, costly excavation is often required for basins. In addition, the
hydraulic head necessary for some devices to function properly may not be
available.
ii) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
iii) Phase 3B:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 3B:
(a) Total of 17.36 acres of drainage area. Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.

f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even. Closed Bottom /
Closed Top Sand Filters require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out which is increased in a close top system to provide space for routine
maintenance of the sand and costs of SCM and adding stormwater detention. Costs rise
further due to anti -floatation measures required.
10) Rainwater Harvesting:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
11 ) Green Roof:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
12) Disconnected Impervious Surface:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
13) Proprietary Underground Stormwater Control Measure (StormFilter by Contech):
a) MDC 1 Volume Based sizing: Sizing for the StormFilter system is in conjunction with
upstream closed detention based on designing the system to provide capture and
treatment of 75% of the first 1.5" rainfall in coastal counties. No upstream open retention
or upstream infiltration is permitted as treatment shall be directed to the cartridges.
b) Contech supplies the upstream detention system which is corrugated metal. Metal pipes
coupled with a high SHWT leads to rusting as the pipes are inevitably scratched during
installation. Thus, reducing the lifespan of the systems and leads to high replacement
costs.
c) Proprietary Underground Stormwater Control Measures utilize proprietary filter
cartridges to provide stormwater treatment. These filter cartridges are typically contained
in pre -cast structures and require replacement after a variable amount of time. Due to
the replacement needs, and based on real life experience, the inside of a precast
structures are rarely shorter than 7' in height. This allows for enough space above the
filter cartridges for an OSHA compliant confined space entry.
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.

(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 3B:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
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d) Placing proprietary underground stormwater control measures in areas of high
sedimentation will reduce the lifespan of the filter cartridges. Devices cannot be used for
sediment control during construction for erosion control.
e) Proprietary Underground Stormwater Control Measures require frequent maintenance:
i) Requires quarterly inspections.
ii) Replace the filter media whenever it fails to function properly after maintenance.
f) No separation required between bottom of SCM and SHWT. However, proprietary
underground stormwater control measures placed in SHWT require anti -buoyancy
measure which also drives up cost.
g) Not Selected due to elevation requirement from flow into SCM to invert out which is
increased further in a closed top system to provide space for routine maintenance of the
filters and costs of SCM and adding stormwater detention. Costs rise further due to anti -
floatation measures required.
14) Proprietary Underground Stormwater Control Measure (Silva Cell by DeepRoot):
a) Small footprint was specifically developed for ultra -urban environments with highly
impervious contributing drainage areas and limited area above ground for stormwater
control and treatment.
b) MDC criteria has a Built Upon Area of 75% or greater.

c) The lowest point of the Silva Cell System shall be a minimum of two feet above the
SHWT; otherwise one foot if supported by a hydrogeologic evaluation prepared by a
licensed professional.
d) Device is fed by surface drainage and has limited stormwater storage capacity.
e) Not Selected due to criteria listed above, mainly BUA 75% or greater requirement.
15) Proprietary Underground Stormwater Control Measure (Filterrra by Contech):
a) Small footprint is designed to work best within small mostly impervious drainage areas.
Such as commercial parking lots, residential streets, parking lots and urban
streetscapes.
b) Device is fed by surface drainage and has limited stormwater storage capacity.
c) Not Selected due to criteria listed above, mainly small drainage area with mostly
impervious area.
16) Proprietary Underground Stormwater Control Measure (BayFilter by ADS):
a) Proprietary Underground Stormwater Control Measures utilize proprietary filter
cartridges to provide stormwater treatment. These filter cartridges are typically contained
in pre -cast structures and require replacement after a variable amount of time. Due to
the replacement needs, and based on real life experience, the inside of a precast
structures are rarely shorter than 6' in height. This allows for enough space above the
filter cartridges for an OSHA compliant confined space entry.
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 313:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.

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b) Proprietary Underground Stormwater Control measures require frequent maintenance:
i) Requires quarterly inspections.
ii) Replace the filter media whenever it fails to function properly after maintenance.
c) Placing proprietary underground stormwater control measures in areas of high
sedimentation will reduce the lifespan of the filter cartridges. Devices can not be used for
sediment control during construction for erosion control.
d) No separation required between bottom of SCM and SHWT. However, proprietary
underground stormwater control measures placed in SHWT require anti -buoyancy
measure which also drives up cost.
e) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out which is increased in a closed top system to provide space for routine
maintenance of the sand and costs of SCM and adding stormwater detention. Costs rise
further due to anti -floatation measures required.
17) Filter Strip:
a) Listed as "Med" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The Level Spreader — Filter Strip is a Secondary SCM. Designed to work in conjunction
with another SCM.
c) See Proposed SCM Solution below
18) Treatment Swale (standard):
a) The 2017 MDC Section E-4 Airports Table 1 states: A treatment swale is a secondary
SCM; however, it may be used on an airport where a primary SCM is not feasible.
b) Listed as "Y" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection. However, the specific MDC #1 states: Swales shall not be
excavated below the Seasonal High Water Table.
i) Swales with bottoms intersecting the SHWT may remain inundated with groundwater
during portions of the year and have insufficient volume available to treat runoff from

the design flow. They are also more prone to developing soggy bottoms and wetland
vegetation.
c) See Proposed SCM Solution below
Proposed SCM Solutions:
19) Overall items which apply to both proposed SCM types:
a) A key objective of the Plan is to address the North Carolina Stormwater Management
Rules (15A NCAC 02H.1000) administered by the North Carolina Department of
Environment and Natural Resources, Division of Water quality.
b) In the 2004 Stormwater Master Plan it was determined that stormwater management at
the Wilmington International Airport should be accomplished primarily with a combination
of extended dry detention basins and grassed swales needed to meet the required 85%
pollutant removal efficiency stipulated under North Carolina Stormwater rules.
i) The extended dry detention basins will also serve to meet the peak discharge
attenuation requirements of the New Hanover County Storm Water Management
Ordinance
ii) Since this time BMP regulations have been updated to the current 2017 MDC
requirements for SCMs.
c) Extended dry detention basins and grasses swales are specifically called for in the 2004
Stormwater Master Plan which was created as a planning tool for providing stormwater
management infrastructure in support of anticipated development activities on airport
property. Final design, supported by topographic survey, wetlands delineation, and
subsurface exploration efforts was left in the hand of the subsequent Engineers.
i) The 2004 Stormwater Master Plan does not specifically list any means of dealing
with SCM location which encounter flat topographic challenges.
ii) The 2004 Stormwater Master Plan does not specifically list a means of best
protecting Jurisdictional wetlands fed by existing drainage patterns.
iii) The 2004 Stormwater Master Plan does not specifically list any means of dealing
with SCM locations which encounter a high Seasonal High Water Table.
(1) The 2004 Stormwater Master Plan included concept sections for an Extended
Dry Detention Basin, on sheet D1.1, without listing a means of dealing with a
shallow Seasonal High Water Table.
d) Our SCMs were designed based upon the approved and existing SCMs from 2005,
2009, and 2012.
e) Extended Dry Detention basins and Grassed Swales were selected and designed to
minimize wildlife habitat and associated risks to aircraft safety.
i) Are listed as "Love' under the Wildlife Habitat column within the 2017 MDC Guidance
on SCM selection.
ii) The 2004 Stormwater Master Plan highlights the need for wildlife hazard issues to be
a primary design consideration. It included a careful review of FAA Advisory Circular
150/5200-33A, "Hazardous Wildlife Attractants On or Near Airports" and consulted
the USDA Wildlife Services to interpret the FAA criteria for context of local
conditions. Wildlife Services has advised that the Advisory Circular guidelines are
appliable at the Wilmington International Airport and recommends the use of

extended dry detention basins and grasses swales rather than wet detentions basins
at the airport.
f) Extended Dry Detention basins and Grassed Swales work in conjunction to provide
treatment and detention for the necessary storm events.
g) Low-cost SCMs selected based upon ILM Airport funding and used in conjunction with
other low-cost SCMs in a manner that meets or exceeds performance standards while
integrating them into the natural features of our site.
h) Extended Dry Detention basin can be used as a sediment basin during construction of
future impervious upon the ILM Business Park lots.
i) Extended Dry Detention Basin 3A is proposed to be utilized as a sediment basin
during Phase 1 of the erosion control plan.
ii) Extended Dry Detention Basin 3B is proposed to be utilized as a sediment basin
during Phase 2 of the erosion control plan.
iii) Option exists for these to be re -used as sediment basins in the future.
i) Ease of maintenance; no OSHA confined entry certification required to inspect or repair;
limited specialized equipment needed to perform maintenance.
j) NOTE: On the attached "Figure 6 — WTDM" delineation map, which was approved by
USACE, there are currently Jurisdictional Wetlands present in the two existing Grassed
Swales and the one Extended Dry Detention basin. Additionally, there are Jurisdictional
Ephemeral Stream channels present within the Extended Dry Detention basin. The
stream channel and wetlands likely extend further into the Extended Dry Detention basin
than our map illustrates since it abuts our delineation scope area limits.
i) One of the three criteria for wetlands is standing water being present at the surface.
(along with soil conditions and established vegetation).
(1) The placement of wetlands within the devices illustrates the SCMs were
designed as compliant devices in 2005, 2009, and 2012. However, .through 2021
optics the SCMs appear to now be existing non -compliant devices which are in
good standing.
(a) Part of the Treatment Swale MDC description describes the current condition
well: Swales with bottoms intersecting the SHWT may remain inundated with
groundwater during portions of the year. They are also more prone to
developing soggy bottoms and wetland vegetation.
(2) With these existing devices being in good standing on the same parcel we
believe they are a valid basis of our design.
(3) Dry Detention basins, with outlet orifices set at the low point, will continue to
drain any groundwater which seeps into the devices. Our design does not include
any upstream splitters/weirs which would retain standing water.
ii) Nearby, wetland "F" if located at approximately the same elevation as our site, yet is
closer to the existing SCMs. Indicating the SHWT within the three existing devices is
higher than the delineated elevation of approximately 13.50' within the grassed
swales.
iii) Additional surface wetlands are present surrounding the Extended Dry Detention on
the 2009 Sheet P-2 "Existing Extended Dry Detention Basin No.1."

k) NOTE: Phase 3B has —1,275 LF of grassed ditches will be indefinitely retained. The
shortest is 235' of a continuous run. These grassed ditches provide some level of pre-
treatment for the existing roadway impervious along Airport Blvd and Gardner Road.
However, we have not tried to quantify or claim credit for these ditches.
20) Extended Dry Detention basin and Treatment Swale similar to 2004 Master Plan along with
the 2005 and 2009 design:
a) Listed as "Y' under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) 2004 Stormwater Master Plan criteria for Extended Dry Basins:
(1) The basin should be steep -sided, narrow, and linearly -shaped.
(a) Basins are steep -sided, narrow, and linearly shaped.
(2) Capture the runoff from a 1" rainfall and release over a period of 48 hours.
(a) Phase 3A captures the runoff from the 1.5" rainfall and releases over a period
of 3.9 days
(i) NOTE: This increased release rate is due to NCDOT Hydro requirement.
(b) Phase 3B captures the runoff from the 1.5" rainfall and releases over a period
of 3 days
(3) Provide a minimum flow length -to -basin width ratio of 3:1.
(a) Phase 3A provides between a 3:1 to a 5:1 length -to -basin width ratio.
(b) Phase 3B provides approximately a 7:1 length -to -basin width ratio.
(4) Provide side slopes in the range of 3:1 to 4:1 (horizontal:vertial).
(a) Side slopes of 3:1 provided.

(5) Install outlet orifice in an enclosed structure with a sump. Provide a trash rack on
the inlet to the structure. Do not provide an open permanent pool.
(a) Outlet orifice provided in an enclosed structure with a sump. Trash rack
provided on inlet to riser structure. Open permanent pool not provided.
(6) Provide a rip -rap or concrete lined low -flow channel from inlet to outlet with a
minimum depth of one (1) foot.
(a) A 9" thick Class A rip -rap channel with one (1) foot of depth provided.
(7) Slope basin bottom at 2% preferred and 1 % minimum grade toward low flow
channel.
(a) Bottom of basins sloped at 1 % toward low flow channel.
(8) Provide heavy equipment access for clean -out and maintenance.
(a) Access provided for heavy equipment.
(9) Provide excess storage in the lower levels of the basin amounting to 20% of the
1" rainfall event runoff volume.
(a) Phase 3A and 3B provide storage to 25% of the 1.5" rainfall event runoff
volume
(10) Provide for peak flow attenuation above the V storm storage, in
accordance with the New Hanover County Storm Water Management Ordinance.
(a) Phase 3A and 3B provide peak flow reductions for the 1, 2, 10, 25, 50, and
100-year storm events above the 1.5" storm storage.
(11) Provide for seeding the basin bottom side slopes and berms with
common Bermuda grass or other appropriate mix. Seed mixture shall not contain
any form of millet, rye grass or other large seed producing grasses.
(a) Bermuda grass, Cynodon Dactylon, is to be installed within SCMs per
Landscape Plans C6.0 and C6.1.
(12) Stabilize the basin within 14 day of construction completion.
(a) Basin to be stabilized within 14 days per note #6 of Erosion Control
Construction Sequence found on Sheet C4.2.
(13) To the extent possible, position the bottom of the basin above the
seasonal high water table.
(a) We acknowledge our proposed design elevation does go below the SHWT
we provided but the 2004 permit states "to the extent possible" and we are
meeting that requirement. The approved 2005 and 2009 Extended Dry
Detention basin is located nearby, under the same Master permit, and was
approved using a Seasonal High Water Table value of 6.0' which dates to the
original Extended Dry Detention basin design. Current field conditions now
include Jurisdictional wetlands within the Extended Dry Detention basin,
showing the Seasonal High Water Table, at the upstream end of the SCM,
exceeded the bottom elevation of the Extended Dry Detention basin (inlet
pipe outlet @ 10.83' and 10.26' per field survey conducted by Paramounte
Engineering Sheet dated 11/20/19). All evidence points to this device is in
good working order and is functioning as designed. Providing evidence that
our proposed alternate means of compliance in regard to the SHWT can also
meet the intent of the NCDEQ treatment regulations.

(b) The 2004 Stormwater Master Plan presents workable solutions for the long
term storm water management needs of the airport. Implementation of the
plan depends on the exact nature, magnitude, and sequence of development
projects which move forward and on funding resources which become
available for construction of stormwater solutions.
(i) Nature:
1. To provide permanent stormwater treatment for forthcoming
Commercial development within the ILM Business Park.
2. All told the permanent Phase 3A and 313 SCMs will allow —11.33
acres of development to proceed. The 11.33 acres include future
internal road. After the Circle K parcel is developed approximately 8
acres will remain.
3. Meaning the majority of the drainage (16.66 ac of the 27.99 acres) will
either be comprised of SCMs or existing right-of-way area along
Airport Blvd and Garner Road.
(ii) Magnitude:
1. Phase 3A and 313 drainage areas account for only —2.1 % of the
overall 1,338.95 acre parent parcel.
2. Or only —8.7% of the overall drainage area covered by permit SW8
050547.
3. The Phase I & II drainage areas currently have in excess of 3 Million
SF of impervious allocation for Future Development. Which is 2.4x
larger than the Phase 3A and 313 drainage areas combined.
(iii) Sequence: "Distributed" SCMs located near the outlet of the respective
drainage area. No future upstream or downstream devised are expected
to be placed in sequence with these devices.
(iv) Funding:
1. ILM Airport is solely funding the construction of the stormwater
devices.
2. ILM is cost -sensitive due existing budgets.
3. ILM is doing this construction in hopes of attracting additional
developers to enter the ILM Business Park by offering pad -ready sites
for development.
4. Current economic conditions, due to COVID, has greatly reduced
flight traffic which has directly reduced their income derived from gate
fees.
5. Long term maintenance costs must be factored into the front-end
design to ensure ILM is not saddled with expensive repairs on an
annual basis.
(c) The 2004 Stormwater Master Plan also states that nothing in this plan is
intended to limit or restrict the airport or its current or prospective tenants with
respect to pursing alternate of modified stormwater management solutions in
various locations.
(14) Provide for safe conveyance of a 100-year storm event.

(a) Extended Dry Detention basins designed to safely convey a 100-year storm
event.
c) NOTE: Draw down time for the Phase 3A Extended Dry Detention basin is limited by
NCDOT Hydrology Department which will not allow an increase in Post -flows for the 10,
25, 50, and 100-yr storms under N. 23rd Street.
21) Treatment Swale similar to 2004 Master Plan along with the 2012 design:
a) 2004 Stormwater Master Plan criteria for Grassed Swales:
(1) Swales will typically be located upstream of extended dry detention basin.
(a) Grassed swales placed directly upstream of extended dry detention basins.
(2) Provide a 0.2% minimum to 4.0% maximum longitudinal slope.
(a) Phase 3A longitudinal slope set at 0.10% due to elevation constraints.
(i) Note the previously approved Phase I & II grassed swales are both
designed at 0.03%
(b) Phase 3A longitudinal slope set at 0.20%
(3) Provide side slopes no steeper than 3:1 (horizontal:vertical) with 5:1 preferred.
The swale cross section should be triangular or parabolic.
(a) Side slopes of 3:1 provided and match the shape of the existing grassed
swales.
(4) Swale bottom should be located above the seasonal high water table
(a) The approved 2012 Pre -Treatment swales are located nearby, under the
same Master permit, and were approved using a Seasonal High Water Table
value of 6.0' which dates to the original Extended Dry Detention basin design.
This test was not completed with the devices. Current field conditions now
include Jurisdictional wetlands within these two pre-treatment swales.
Showing the Seasonal High Water Table exceeded the bottom elevation of
the pre-treatment swales (bottom @ 11.47' and 11.14' per Paramounte
Engineering Sheet C3.0 dated 10/9/12). These devices are in good working
order and are functioning as designed. Providing evidence that our proposed
alternate means of compliance in regards to the SHWT can also meet the
intent of the NCDEQ treatment regulations.
(b) The 2004 Stormwater Master Plan presents workable solutions for the long
term storm water management needs of the airport. Implementation of the
plan depends on the exact nature, magnitude, and sequence of development
projects which move forward and on funding resources which become
available for construction of stormwater solutions.
(i) Nature:
1. To provide permanent stormwater treatment for forthcoming
Commercial development within the ILM Business Park.
2. All told the permanent Phase 3A and 3B SCMs will allow -11.33
acres of development to proceed. The 11.33 acres include future
internal road. After the Circle K parcel is developed approximately 8
acres will remain.

3. Meaning the majority of the drainage (16.66 ac of the 27.99 acres) will
either be comprised of SCMs or existing right-of-way area along
Airport Blvd and Garner Road.
(ii) Magnitude:
1. Phase 3A and 3B drainage areas account for only —2.1 % of the
overall 1,338.95 acre parent parcel.
2. Or only —8.7% of the overall drainage area covered by permit SW8
050547.
3. The Phase I & II drainage areas currently have in excess of 3 Million
SF of impervious allocation for Future Development. Which is 2.4x
larger than the Phase 3A and 3B drainage areas combined.
(iii) Sequence: "Distributed" SCMs located near the outlet of the respective
drainage area. No future upstream or downstream devised are expected
to be placed in sequence with these devices.
(iv) Funding:
1. ILM Airport is solely funding the construction of the stormwater
devices.
2. ILM is cost -sensitive due existing budgets.
3. ILM is doing this construction in hopes of attracting additional
developers to enter the ILM Business Park by offering pad -ready sites
for development.
4. Current economic conditions, due to COVID, has greatly reduced
flight traffic which has directly reduced their income derived from gate
fees.
5. Long term maintenance costs must be factored into the front-end
design to ensure ILM is not saddled with expensive repairs on an
annual basis.
(5) Swales should be designed for ready mowing with standard mowing equipment.
(a) Designed for mowing with standard mowing equipment.
(6) Flow velocity should be limited to 2 feet per second for the 2-year design flow
and a non -erosive velocity for the 10-year design flow.
(a) Phase 3A Grass Swale: 2-year velocity = 1.12fps; 10-year velocity = 1.22 fps
(b) Phase 3B Grass Swale: 2-year velocity = 1.31fps; 10-year velocity = 1.42 fps
(7) An attempt shall be made to provide 100 linear feet of swale per acre of drainage
area. No less than 50 linear feet of swale per acre shall be provided.
(a) The proposed Phase 3A swale is 150 LF in length and accounts for 4.89
acres of drainage area. Which equates to 30.67 LF per acre. The proposed
3B swale is 150 LF in length and accounts for 17.36 acres of drainage area.
Which equates to 8.64 LF per acre.
(i) By the 501f/ac criteria the Phase 3A swale should be no less than 244.5
LF in length.
(ii) By the 501f1ac criteria the Phase 3B swale should be no less than 868 LF
in length.

(iii) However, when compared to the existing Phase I and II grass swales our
proposed amount far exceeds what has been accepted in the past. Those
two grassed swales total 300 LF in length and handle 287.63 acres.
Which means they provide only 1.04 If/ac.
(iv) Based on the "decentralized" SCM locations within the ILM business park,
it is key to try and preserve as much developable area land as possible
while also complying with regulations. A quick calculation shows that a
42' wide swale (top of bank to top of bank), which is 1,112 LF long, would
encompass more than 1.07 acres of developable land. Thus eliminating
13% (1.07 ac / 8 ac) of the remaining developable land within Phase 3A
and Phase 3B.
(8) Provide for seeding the swale with common Bermuda grass or other appropriate
mix. Seed mixture shall not contain any form of millet, rye grass or other large
seed producing grasses.
(a) Bermuda grass, Cynodon Dacty/on, is to be installed within SCMs per
Landscape Plans C6.0 and C6.1.
(9) Stabilize the swale with 14 days of construction completion.
(a) Basin to be stabilized within 14 days per note 46 of Erosion Control
Construction Sequence found on Sheet C4.2.
It is our professional opinion that the stormwater solution proposed meets the 2004 Stormwater
Master Plan based on the information provided above and the guidance provided by that permit.
In addition, we have extensively evaluated, in detail, many other SCM alternatives and found
the solution proposed to be the best alternative to provide stormwater treatment.
b. The 2004 approved "Stormwater Master Plan" document for this alternative design
indicates for grassed swales, that the "swale bottom should be located above the
seasonal high water table". The proposed design, however, appears to position the
bottom of the swales below the seasonal high water table. It is understood that a clay
liner is proposed, however, it is my understanding that clay liners are more effective
at keeping water in than keeping water out. The grassed swale requirements of the
"Stormwater Master Plan" do not make the same "to the extent possible" distinction
as the dry detention basin requirements. Please confirm the intended design and
ensure this requirement for the alternative design is met.
Response: Based upon further discussion with our Sr. Geotechnical Engineer we
have removed the clay liner from our design. His experience has been that clay
liners are equally effective in keeping water in a device as out of a device however,
constructability concerns in this location and long term potential uplift have caused
us to reevaluate and therefore remove clay liners from the design. Similarly, a
synthetic liner has also not been chosen. This evaluation of the design also includes
all available evidence pointing to the existing stormwater control system functioning
properly and in good order and therefore our proposed design providing an equal
level of treatment meeting the 2004 design criteria.

2. 15A NCAC 02H.1042(2)(a): The signatures provided on the submitted application,
operation and maintenance agreements, and proposed deed restrictions and protective
covenants were all copies. These documents must include an original signature. The
response letter included with the January 21, 2021 resubmittal indicated that "We remain
in the process of obtaining the original signed documents and will provide upon receipt."
The originally signed documents, however, were never received. Please provide an
original signature for all documents that require the applicant's signature.
Response: Original Signatures on the O&M agreements have been provided under
different cover letter.
3. 15A NCAC 02H.1042(2)(a)(iv):
a. In order to ensure the SWU-101 form remains consistently updated and represents
the entire permitted condition, Section IV.10 of the application must reflect all
drainage areas covered in this permit, including the Phase I & II drainage areas.
Please update Section IV.10 of the application to reflect all drainage areas permitted
under SW8 050547.
F%valiu gad: The p iaad 1 & � w ainage areas have now vuwn, a uiuuCu vi 1 U id SWU-
101 form.
b. Drainage Area 3C in Section IV.10 of the submitted application indicates that there is
312,094 square feet of "other on -site" built -upon area (BUA) and 129,628 square feet
of "future" BUA, however, there is no proposed SCM(s) to treat this proposed BUA. It
is noted that there is some existing BUA. Please confirm one of the following, provide
additional explanation and update the application package appropriately:
is No SCM is proposed for Drainage Area 3C at this time and no BUA is
proposed beyond the existing BUA; or
ii. A new SCM is proposed to treat Drainage Area 3C and the application is
being revised to include the SCM; or
iii. Drainage Area 3C is an area of low density and the application package will
be revised to include this area of low density;
Response: Phase 3C drainage area numbers have been revised to remove "future
impervious." No SCM is proposed for DA 3C at this and no BUA is proposed beyond
the existing.
c. Section IV.7 of the application indicates that the total project area covered under
SW8 050547 is 27.99 acres. SW8 050547, however, currently has an approved total
project area of 322.3 acres. Please confirm the correct total project area and ensure
it is represented consistently throughout the entire application package.
Response: Our application has been updated to reflect the entire 322.3 acres per
the original permit. We are now showing on our application Phase I, Il, and III.

4. 15A NCAC 02H.1042(2)(g): The submitted drainage area plan sheet does not clearly
show the proposed Drainage Area 3C. In order to support the entire previously approved
Phase III area is covered by this modification, please include the entire area on the
drainage area plan sheet and clarify the proposed Drainage Area 3A, Drainage Area 3B
and Drainage Area 3C.
Response: DA3.0 has been revised to now include Drainage Area 3C, now shown with
a transparent hatch.
5. 15A NCAC 02H. 1 042(2)(f) and .1042(2)(a)(iv): The calculations for Extended Dry
Detention Basin 3A indicates that the total impervious area draining to the basin is 1.67
acres (72,746 square feet). Section IV.10 of the application, however, indicates there is
116,598 square feet of BUA proposed in drainage area 3A. Please confirm the correct
amount of BUA proposed in drainage area 3A and ensure it is represented consistently
throughout the entire application package.
Response: The impervious area draining to extended dry detention basin 3A is 2.67
Acres. The calculations have been updated and the impervious area is now consistent.

Zorda, Garrett D
From: Zorda, Garrett D
Sent: Thursday, April 8, 2021 3:16 PM
To: Brian Downs; Rick Baker
Cc: Granseur Dick; Jacob Dooley, Andy Priolo - Couche Tard ([e-mail]); Hall,
Christine
Subject: RE: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8
050547) Request for Additional Information
Good Afternoon All,
While going through the response package, it was noticed that the technical justification response provided was not
signed and sealed by a licensed professional. In order to proceed with this variation, as proposed, we will need this
technical justification document signed an sealed. Can you please provide a copy of the technical justification response
that is signed and sealed by a licensed professional?
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct '"Please note the change to my direct phone number"
aarrett.zordaO ncden r.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405
e:!r5:0"f�D E
��Q � ;*am
En-'Oi1 ct. ,rtespon7 sth`: t') and frfi ii i`?i a �'+e '� ' %t to the
�dc: :�; ,:ah�e
;Vort:f� {-arc;{-na Pt;rlic i .!CIS Lativ find C: az be '-"iscloaed to l??i TY papti.es.
From: Brian Downs <[e-mail]>
Sent: Friday, March 26, 20213:53 PM
To: Zorda, Garrett D <[e-mail]>; Rick Baker <Rick.Bake [e-mail]>
Cc: Granseur Dick <[e-mail]>; Jacob Dooley <[e-mail]>; Andy Priolo - Couche Tard
([e-mail]) <[e-mail]>; Hall, Christine <Christine. Hall@ ncdenr.gov>
Subject: RE: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8 050547) - Request for
Additional Information
4AU T iGiY- Externai emaii. Oo not click iinks or opan atrarnmwnt:, umla s you verify. Send all spsoicious email as mn at"_ad'a-,,ert to
Report Sparn.

I CSC- k
• 5410 Trinity Road
TIMMONS GROUP Suite102
,, YQVR v S: -N A -I.-SVED Raleigh, NC 27607
i TRANSMITTAL
NCDEQ — Christine Hall
TO:
Stormwater Department
127 Cardinal Drive Extension
Wilmington, NC 28405
P 919.866.4951
F 919.859.5663
www�,cwn
Date: 3/29121 Job#: 37630.054
Circle K — NTI Airport Blvd Wilmington —
Project: NCA 15
Reference: Submittal #3
Copies Sent To:
COPIES
DATE
NUMBER
DESCRIPTION
2
03/29/2021
1
Stormwater Management Permit Application (to be inserted into
originals)
1
03/29/2021
2
SCM Supplements Forms
1
03/29/2021
3
Calculations Package included SHWT report)
2
03/29/2021
4
Rolled 24" x 36" plans
2
03/29/2021
5
Comment Response Letter
1
03/29/2021
6
Stormwater Feasibility Notes
1
03/29/2021
7
US Fish and Wildlife Services Request
1
03/29/2021
8
Preliminary Jurisdictional Waters of the US Ma
1
03/29/2021
9
NCDOT Hydro Email thread concerning re and post flows
1
03/29/2021
10
Preliminary Wetland Determination Exhibit
1
03/29/2021
11
Previously Approved Extended Detention Basin
1
03/29/2021
12
CD co-ntaining pdft of all documents
THESE ITEMS ARE TRANSMITTED:
If enclosures are not as noted, please notify us at once.
COMMENTS:
Internal exhibits used during design also in CD for reference
Thank You,
Brian Downs
Project Manager
Timmons Group
CIVIL ENGINEERING I ENVIRONMENTAL I SURVEYING I GIS I LANDSCAPE ARCHITECTURE I CONSTRUCTION SERVICES

a 6 -1- 21'
*49'
I
5410 Trinity Road
TIMMONS GROUP Suite102
YOUR VISION ACHIEVED THROUGH OURS. Raleigh, NC 27607
TRANSMITTAL
NCDEQ - Christine Hall
TO:
Stormwater Department
127 Cardinal Drive Extension
Wilmington, NC 28405
P 919.866.4951
F 919.859.5663
www hnM0ffs men
Date: 3129121 Job#: 37630.054
Circle K - NTI Airport Blvd Wilmington -
Project: NC.115
Reference: Submittal #3
Copies Sent To:
COPIES
DATE
NUMBER
DESCRIPTION
2
03/29/2021
1
Stormwater Management Permit Application (to be inserted into
6ri inals
1
03/29/2021
2
SCM Supplements Forms
1
03/29/2021
3
Calculations Package included SHWT report)
2
1 03/29/2021
4
Rolled 24" x 36" plans
2
03/29/2021
5
Comment Response Letter
1
03/29/2021
6
Stormwater Feasibility Notes
1
03/29/2021
7
US Fish and Wildlife Services Request
-Preliminary
1
03/29/2021
8
Jurisdictional Waters of the US Ma
1
03/29/2021
9
NCDOT Hydro Email thread concerning re and post flows
1
03/29/2021
10
Preliminary Wetland Determination Exhibit
1
03/29/2021
11
Previously Approved Extended Detention Basin
1
03/29/2021
12
CD containing dfs of all documents
THESE ITEMS ARE TRANSMITTED:
If enclosures are not as noted, please notify us at once.
COMMENTS:
internal exhibits used during design also in CD for reference
Thank You,
Brian Downs
Project Manager
Timmons Group
CIVIL ENGINEERING I ENVIRONMENTAL I SURVEYING I GIS I LANDSCAPE ARCHITECTURE CONSTRUCTION SERVICES

a �• t
5410 Trinity Road P 919.866.4951
[� ` P Suite 102 F 919.859.5663
�t I G R Raleigh, NC 27607 www�
To:
Garrett Zorda, Environmental Engineer
NCDEQ, Wilmington Regional Office
Date:
March 29, 2021
Project Name:
Circle K — NTI Airport Blvd Wilmington — NC115
Project number:
37630.054
Project Contact:
Brian Downs
Phone:
919-866-4504
E-Mail:
[e-mail]
Please see our response to your comments in red below each comment.
Garrett Zorda, Environmental Engineer I email: [e-mail]
15A NCAC 02H.1003(6) and the 2004 approved Stormwater Master Plan document: The
response to Items #1.b and 1.c of the previous request for additional information indicate
that the dry detention basins and grassed swales are designed to provide the minimal
separation to the seasonal high water table. The resulting design of the two dry
detention basins and two grassed swales, however, still set these devices between 4.5
feet and 6.75 feet below the seasonal high water table. These two new dry detention
basins and grassed swales must either meet the requirements in the previously
approved agreement from 2004 or demonstrate they are an equal or better variation
under the 2017 rules.
Response: The approved 2004 Stormwater Master Plan provided a technical framework
for processing future NCDENR Stormwater permits for individual development projects
on airport property. The document provided two stormwater management concepts for
the west side of the airport. A "centralized' and a "distributed" concept. Previous Master
stormwater improvements to -date have relied upon the initial 2005 Centralized
stormwater concept with the primary solution being the existing Extended Dry Detention
basin which lies southwest of the main circular parking area. Through several updates,
the ILM Master Planned stormwater orphaned the Phase 3 area for it to be inlcuded in a
stormwater solution at a later date.
After a deep dive into the site constrains, we understand why this area was not
approached head-on until this time. Based upon site constraints, to be better detailed
later, the "distributed" concept was selected to provide a permanent stormwater solution
to as much of the 34.71-acre Phase 3 drainage area as possible. This solution was best
suited for the remaining area because it can be more readily phased than the centralized
concept. This "decentralized" approach required new SHWT tests which revealed an
issue that is likely prevalent elsewhere on -site namely, a high SHWT which is between
8"-12" below existing grade.
ENGINEERING i DESIGN I TECHNOLOGY

Additional consideration was given to current MDC regulations. We utilized the latest
available version for each SCM type on the NCDEQ website for our analysis. Both
originally and within this document.
As all parties are aware, this is a unique site that has established its own set of
requirements that does not necessarily follow the standard rules and guidelines of the
DEQ Stormwater program. Knowing this and throughout our design, we have consulted
with no less than 7 design professionals (6 with PE licensure in NC) within our company,
all with extensive stormwater design experience in all regions of NC including the
Coastal Plain to make sure we are providing stormwater treatment to meet the intent of
the stormwater rules and follow closely the 2004 stormwater Master Plan for ILM.
A concise general narrative is difficult due to the project complexity however, we are
providing the necessary information to respond to your comments but in as concise
manner as possible.
1) For reference, a concept "distributed" design was included in the 2004 Stormwater
Master Plan as shown on sheet PR1.2.
a) The "distributed" stormwater concept involves using multiple smaller
extended dry detention basins throughout the drainage area. Based on the
idea that stormwater is detained and treated locally at each project site and
then conveyed off airport property.
2) Our site falls within the western portion of the airport property and retains much of
the original infrastructure which dates back to World War II era construction. The
approved 2004 Stormwater Master Plan categorized this area by stating: the system
of open channels, culverts, and smaller closed systems which drain this area is
generally in poor condition and of limited capacity. This area remains sparsely
developed and requires significant stormwater infrastructure improvements to
accommodate future development.
3) Our site currently contains 1.84 acres of impervious surface (roads) which is not
currently being treated by any SCMs.
4) Our project area includes two offsite discharge points:
a) Our project site falls entirely within an area specified for "Airport Business
Park Development / Redevelopment" per 2004 sheet PR1.2.
b) Drainage areas include part of Sub -Basin 1, all of Sub -Basin 2, and part of
Sub -Basin 3 as outlined in Section 3 of the 2004 Stormwater Master Plan.
These areas are illustrated on sheets EX1.0 and EX1.4 of the 2004
Stormwater Master Plan.
c) This "decentralized" approach favors reintroducing runoff from impervious
surfaces into the natural environment as close to the impervious surfaces as
possible in line with recent trends in stormwater management.
5) "High Density" projects are projects involving more than 30 percent built -upon area.
Stormwater controls need to be implemented as high density development occurs
involving a net increase in built -upon area.

a) Phase 3A will now exceed the 30% BUA upper limit for "Low Density" with the
proposed C-Store project.
b) However, Phase 3B will currently remain under the 30% BUA upper limit for
"Low Density" and is being undertaken at this time to proactively provide a
means of treating stormwater prior to future high density development.
6) Primary SCM selection criteria included: standing water near airport, maintaining
Jurisdictional and isolated wetlands, stream channels, and riparian buffers.
a) During development of the approved 2004 Stormwater Master Plan, the
wildlife hazard issue (standing water near airport) was recognized as a key
issue in development of the Plan. It was considered prudent to review wildlife
concerns from a local, site specific perspective as well as in the nation-wide
context of the FAA Wildlife Advisory Circular No. 150/5200-33.
b) USACE Jurisdictional wetlands and riparian buffers occur immediately
downstream of Phase 3B per our 2020 delineation.
c) Downstream of Phase 3A is a culvert which is outside of our Environmental
mapping scope since if falls off the ILM property. However, the National
Wetlands Inventory map illustrates a 13.77 acres Freshwater Forested/Shrub
wetland, classified as PFO1/2F, immediately downstream of the Phase 3A
culvert.
7) Secondary SCM selection concerns included: maintenance and construction costs
for ILM Airport which is a public entity.
a) This selection criteria are supported by the 2004 Stormwater Master plan
which includes funding resources as a criteria within Section XIII.
8) Our scope it is to "complete" Stormwater Treatment for as much of the Phase 3
drainage area as possible. Currently most of the drainage area is undeveloped. Our
scope also includes the Circle K development.
(a) Most of the remainder ILM Business Park land within the drainage areas will
not be built -out at this time.
(b) Future construction is expected to happen in a number of different phases
because our drainage area includes at least 3 additional Master Planned
parcels.
(c) Before full build -out occurs, there will be an indefinite period of time of high
sediment input into the SCMs during inactivity. Supplemented by times of
even greater sediment input into the SCMs during the future phased
construction.
(d) SCM selection must factor in these periods of high sedimentation to reduce
the risk of shortening the functional lifespan of an SCM.
9) Our site contains topographic challenges due to its proximity to the coast.
(a) For Phase 3A:
(i) The Circle K will primarily drain by sheet flow across vegetated surfaces
into the SCM.
(ii) Stormwater will be conveyed under roadways by culvert pipes.
1. Required cover is needed to pass water under the roads. Roads are
required for interconnectivity of the individual lots.

(iii) The water then passes through the pre-treatment Grassed Swale at
0.10% and then through the Extended Dry Detention basin at 1.0%.
(iv) Ultimately crossing under N. 231d Street via a 24" RCP culvert pipe with
an upstream invert of 14.00'.
(v) All told, the water for Phase 3A covers—1,000+ LF with a net 10' of
elevation change for an average of 1 % slope in a perfect world without
additional constraints.
1. This ideal 1% slope is not possible and the real world constraints will
be detailed later.
(b) For Phase 3B:
(i) The restricting elevation is the outlet of an 18" RCP pipe which crosses
under Airport Blvd and outlets at 19.05'.
(ii) The water will then be conveyed by a combination of ditches and pipes.
1. Culvert pipes with required cover is needed to pass water under the
future loop road. Roads are required for interconnectivity of the
individual lots.
(iii) The water then passes through the pre-treatment Grassed Swale at
0.20% and then through the Extended Dry Detention basin.
(iv) An ultimate outlet is to a buffered intermittent stream at 12.50'.
(v) All told the water for Phase 3B covers —950+ LF, south of Airport Blvd,
with a net 6.55' of elevation change for an average of 0.69% slope in a
perfect world without additional constraints.
1. This ideal 0.69% slope is not possible and the real world constraints
will be detailed later.
(c) We evaluated connecting to the existing SCMs via a swale and/or pipes
under the "Centralized" concept. However, this approach presented
numerous challenges. Namely a concern about backwater issues, all the way
to the Circle K leased parcel and dewatering Jurisdictional wetlands.
(i) An abundance of INTERNAL exhibits are included with the submittal
showing the various configuration we designed, to various levels, before
submitting this design. More exist but the additional ones are largely
redundant.
10) Our site has numerous physical constraints (topography and wetlands) and it has
proven especially challenging to settle on an appropriate SCM type. In this case, we
believe it is necessary to modify the standard SCM designs, due to site
characteristics, to provide the required level of permanent stormwater treatment.
More specifics on proposed modifications are provided below in #19, #20, and #21.
a. The purpose of the 2004 "Stormwater Master Plan" alternative design document was
to preserve water quality standards while also ensuring the constructed practice did
not attract wildlife that could become a hazard to air traffic. This agreement was later
supported by G.S. 143-214.7(c3), which was added by Session Law 2012-200, and
confirms that the Division does not require the use of wet ponds or other SCMs that
promote standing water on or near public airports. While the "Stormwater Master

Plan" recommends the use of Extended Dry Detention Basins combined with
grassed swales, it does not "limit or restrict the airport or its current or prospective
tenants with respect to pursuing alternative or modified stormwater management
solutions in various locations." Since the inception of the "Stormwater Master Plan",
other primary SCM options that do not retain a permanent pool and/or promote
standing water have become available and approved by the Division (i.e. sand filters,
underground infiltration trenches, proprietary systems such as ADS BayFilters, etc.).
Please confirm if any of the more recent SCM options were considered to treat the
runoff from the proposed development. Please also provide additional justification
that the current design of a combination of grassed swales and dry ponds meets all
of the requirements of the "Stormwater Master Plan" or that they are an equal or
better variation to these other primary SCMs.
Response_
In our evaluation of stormwater treatment, we reviewed all 2004 Stormwater Master
Plan and current MDC options extensively to determine what SCM or combination of
SCM's will provide treatment to meet the 2004 Master Plan or 2017 DEQ rules.
Below is our evaluation of each SCM.
2004 and 2017 SCM devices were considered:
1) Bioretention with, or without, underdrain:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #1: Minimum of 2' separation required above the SHWT.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM Selection.
d) The 2004 Master Plan excluded "bioretention areas" from consideration at ILM based
upon the expectation they would create conditions that attract wildlife species which are
hazardous to aviation.
e) Not Selected due to criteria listed above mainly HIGH wildlife habitat and 2004 plan
excluding bioretention.
2) Stormwater Wetland:
a) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The 2004 Master Plan excluded "extended detention wetlands" and "pocket wetlands"
from consideration at ILM based upon the expectation they would create conditions that
attract wildlife species which are hazardous to aviation.
c) Not Selected due to criteria listed above - HIGH wildlife habitat and 2004 plan excluding
constructed wetlands.

3) Wet pond:
a) Listed as "High" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The 2004 Master Plan strongly advocates avoidance of wet detention basins and
recommends the use of extended dry detention basins for stormwater management.
c) Not Selected due to criteria listed above - HIGH wildlife habitat and 2004 plan avoidance
of wet ponds bioretention.
4) Permeable Pavement:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #2: Minimum of 2' separation required above the SHWT for infiltration
pavement systems; Minimum 1' for detention pavement systems.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) The 2017 MDC Section E-4 Airports Table 1 states: It is best implemented in areas that
receive relatively infrequent traffic.
i) However, the areas to be paved surround the primary Airport entrance and will
receive frequent traffic.
d) Not Selected due to minimal amount of pavement proposed and SHWT elevation.
5) Infiltration Device:
a) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #2: Minimum of 2' separation required above the SHWT.
b) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
c) The 2004 Master Plan excluded "infiltration devices" from consideration at ILM based
upon the expectation they would create conditions that attract wildlife species which are
hazardous to aviation.
d) Not Selected - 2004 Master Plan excluding infiltration devices.
6) Dry Pond (standard):
a) Listed as "Y" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) Listed as "N" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection.
i) MDC #1: Minimum of 6" separation required above the SHWT.
ii) Utilizing a shallower, and wider, Dry Detention basin is not feasible due to the SHWT
being 8" or 12" below existing surface. Such an approach would require raising the
vast majority of the drainage areas with fill material. Which would have a substantial
impact on the existing roadway network and would require a high cost for the needed
amount of fill material.

c) The 2017 MDC Section E-4 Airports Table 1 states: Dry Detention basins do pond water
for more than 12 hours after storm events but still may be desired to treat a large
drainage area.
d) See Proposed SCM Solution below
7) Sand Filter (Open Bottom/Open Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be two feet for open -bottom
designs.
c) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even.
d) An open top device would require surface flow into the device. Sand Filters require 1.5'
(18" of filter media). Presenting a ponding depth issue.
i) Phase 3A:
(1) Has -10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.
(a) Effectively 1' of elevation would be left for treatment storage atop of the open
top sand filter. Not accounting for a height reduction for emergency overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase -313:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlet at 14.80' and
EW200 outlets at 12.80' for an ultimate tie-in at 12.50'.
(a) Effectively 0.8' of elevation would be left for treatment storage atop of the
open top sand filter. Not accounting for a height reduction for overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
iii) In areas of low relief, the hydraulic head necessary for some devices to function
properly may not be available.

Figure 1: Open Bottom Sand Filter Example: Cross -Section
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AT 15-101"1-1,111 S:q
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ZEZ--HATED STANDPIPE a31
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PERFORATED FFE SOLO Pff
SEASONALHM a
WATER TAKE V 21
e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 3B:
(a) Total of 17.36 acres of drainage area.
(i) Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.
f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do not mitigate the peak flow from a storm event. Sand Filters
require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to SHWT and possible saturation of sand media, drainage area size,
elevation requirement from flow into SCM to invert out and costs of SCM and adding
stormwater detention.
8) Sand Filter (Closed Bottom/Open Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
i) Phase 3A:
(1) High sediment input can significantly reduce the longevity of sand filters.
(2) Currently proposed as —32% impervious.

(3) Phase 3A has 1.07 acres of allocated future impervious. With little, to no area, to
add erosion control measures upstream of the SCM before sediment input would
enter the sand filter.
ii) Phase 313:
(1) Sand filters function much better when the drainage area is highly built -upon
because this will greatly reduce the amount of fines that reach the sand filter and
potentially cause clogging.
(2) Currently proposed as —13.7% impervious. Pervious is upstream of SCM and
cannot be graded away from SCM.
(3) Phase 3B has 6.05 acres of allocated future impervious. With few areas to add
erosion control measures upstream of the SCM before sediment input would
enter the sand filter.
b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be one foot for closed bottom
designs. Exceptions to the one foot SHWT separation may be made if the applicant
provides documentation that the design will neither float nor drain the water table.
c) Culvert pipe under N. 23ro Street is currently undersized. Backwater into a Phase 3A
sand filter would likely occur prior to water overtopping the road. Extending the period of
time the filter media is surcharged.
d) Sand Filters require 1.5' (18" of filter media).
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23ro at 14.00' elevation.
(a) Effectively 1' of elevation would be left for treatment storage atop of the open
top sand filter. Not accounting for a height reduction for overland overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 313:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(a) Effectively 0.8' of elevation would be left for treatment storage atop of the
open top sand filter. Not accounting for a height reduction for overland
overflow.
(b) Thus, expanding the footprint required for the device which drives up costs
and reduces developable area.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.

iii) In areas of low relief, the hydraulic head necessary for some devices to function
properly may not be available.
e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 313:
(a) Total of 17.36 acres of drainage area. Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.
f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even. Closed Bottom
Sand Filters require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out and costs of SCM and adding stormwater detention. Costs rise further due to
anti -floatation measures required.
9) Sand Filter (Closed Bottom/Closed Top):
a) Listed as "N" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
i) Phase 3A:
(1) High sediment input can significantly reduce the longevity of sand filters.
(2) Currently proposed as ^-32% impervious.
(3) Phase 3A has 1.07 acres of allocated future impervious. With little, to no area, to
add erosion control measures upstream- of the SCM before sediment input would
enter the sand filter.
ii) Phase 3B:
(1) Sand filters function much better when the drainage area is highly built -upon
because this will greatly reduce the amount of fines that reach the sand filter and
potentially cause clogging.
(2) Currently proposed as —13.7% impervious. Pervious is upstream of SCM and
cannot be graded away from SCM.
(3) Phase 313 has 6.05 acres of allocated future impervious. With few areas to add
erosion control measures upstream of the SCM before sediment input would
enter the sand filter.

b) The 2017 Section C-6 Sand Filter MDC 1 states: The minimum separation between the
lowest point of the sand filter system and the SHWT shall be one foot for closed bottom
designs. Exceptions to the one foot SHWT separation may be made if the applicant
provides documentation that the design will neither float nor drain the water table.
c) Culvert pipe under N. 23rd Street is currently undersized. Backwater into the sand filter
would likely occur prior to water overtopping the road. Extending the period of time the
filter media is surcharged.
d) Sand Filters require 1.5' (18" of filter media). MDC Recommendation #2 calls for access
the inside of the box. Based on real life experience the inside of a closed bottom sand
filter should be no less than 5' in height. (Preferrable 65, but we'll use 5' for this
description.) The 5' height allows enough space, above the media, for an OSHA
compliant confined space entry. Which is necessary to remove 1" or 2" of sand for
remediation. This removal is a manual process.
i) In areas of low relief, costly excavation is often required for basins. In addition, the
hydraulic head necessary for some devices to function properly may not be
available.
ii) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
iii) Phase 313:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
e) MDC Recommendation 1 (Drainage Area):
i) It is recommended to grade pervious areas to drain away from sand filters and to
limit the drainage area of a sand filter to five acres or less.
(1) Phase 3A:
(a) 4.89 acres in size
(2) Phase 313:
(a) Total of 17.36 acres of drainage area. Exceeds 5 acres in size.
(b) Sand filters with smaller drainage areas (less than five acres) usually have
fewer maintenance issues. Sand Filters may only handle smaller flows and
can become overwhelmed if sited at the outlet of a large drainage area.
(c) Location of existing impervious within roads reduces our ability to provide
multiple sand filters, sized for 5 ac or less, throughout the development to
provide even more "decentralized' treatment.

f) The 2017 MDC Section E-4 Airports Table 1 states: Sand Filters are a comparatively
expensive practice and do no mitigate the peak flow from a storm even. Closed Bottom
Closed Top Sand Filters require frequent maintenance:
i) Requires quarterly inspections.
ii) Skim the sand media at least once a year.
iii) Replace the sand filter media whenever it fails to function properly after
maintenance.
g) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out which is increased in a close top system to provide space for routine
maintenance of the sand and costs of SCM and adding stormwater detention. Costs rise
further due to anti -floatation measures required.
10) Rainwater Harvesting:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
11) Green Roof:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
12) Disconnected Impervious Surface:
a) Not Selected - Insufficient proposed rooftop area. The majority of impervious will be
roadways or parking areas.
13) Proprietary Underground Stormwater Control Measure (StormFilter by Contech):
a) MDC 1 Volume Based sizing: Sizing for the StormFilter system is in conjunction with
upstream closed detention based on designing the system to provide capture and
treatment of 75% of the first 1.5" rainfall in coastal counties. No upstream open retention
or upstream infiltration is permitted as treatment shall be directed to the cartridges.
b) Contech supplies the upstream detention system which is corrugated metal. Metal pipes
coupled with a high SHWT leads to rusting as the pipes are inevitably scratched during
installation. Thus, reducing the lifespan of the systems and leads to high replacement
costs.
c) Proprietary Underground Stormwater Control Measures utilize proprietary filter
cartridges to provide stormwater treatment. These filter cartridges are typically contained
in pre -cast structures and require replacement after a variable amount of time. Due to
the replacement needs, and based on real life experience, the inside of a precast
structures are rarely shorter than 7' in height. This allows for enough space above the
filter cartridges for an OSHA compliant confined space entry.
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.

(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 3B:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.
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d) Placing proprietary underground stormwater control measures in areas of high
sedimentation will reduce the lifespan of the filter cartridges. Devices cannot be used for
sediment control during construction for erosion control.
e) Proprietary Underground Stormwater Control Measures require frequent maintenance:
i) Requires quarterly inspections.
ii) Replace the filter media whenever it fails to function properly after maintenance.
f) No separation required between bottom of SCM and SHWT. However, proprietary
underground stormwater control measures placed in SHWT require anti -buoyancy
measure which also drives up cost.
g) Not Selected due to elevation requirement from flow into SCM to invert out which is
increased further in a closed top system to provide space for routine maintenance of the
filters and costs of SCM and adding stormwater detention. Costs rise further due to anti -
floatation measures required.
14) Proprietary Underground Stormwater Control Measure (Silva Cell by DeepRoot):
a) Small footprint was specifically developed for ultra -urban environments with highly
impervious contributing drainage areas and limited area above ground for stormwater
control and treatment.
b) MDC criteria has a Built Upon Area of 75% or greater.

c) The lowest point of the Silva Cell System shall be a minimum of two feet above the
SHWT; otherwise one foot if supported by a hydrogeologic evaluation prepared by a
licensed professional.
d) Device is fed by surface drainage and has limited stormwater storage capacity.
e) Not Selected due to criteria listed above, mainly BUA 75% or greater requirement.
15) Proprietary Underground Stormwater Control Measure (Filterrra by Contech):
a) Small footprint is designed to work best within small mostly impervious drainage areas.
Such as commercial parking lots, residential streets, parking lots and urban
streetscapes.
b) Device is fed by surface drainage and has limited stormwater storage capacity.
c) Not Selected due to criteria listed above, mainly small drainage area with mostly
impervious area.
16) Proprietary Underground Stormwater Control Measure (BayFilter by ADS):
a) Proprietary Underground Stormwater Control Measures utilize proprietary filter
cartridges to provide stormwater treatment. These filter cartridges are typically contained
in pre -cast structures and require replacement after a variable amount of time. Due to
the replacement needs, and based on real life experience, the inside of a precast
structures are rarely shorter than 6' in height. This allows for enough space above the
filter cartridges for an OSHA compliant confined space entry.
i) Phase 3A:
(1) Has —10' of vertical relief from building to outlet point. However, this is reduced to
2.5' once the culvert pipe crosses under the new Private Street. EW104 outlets at
16.50' and EW100 conveys water under N. 23rd at 14.00' elevation.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3A drainage area.
ii) Phase 3B:
(1) Has 6.55' of vertical relief from the 18" RCP culvert pipe under Airport Blvd and
the final discharge point. However, this is reduced to 2.3' once the culvert pipe
crosses under the future loop road. EC207 and EW210 outlets at 14.80' and
EW200 outlets at 12.80' for a tie-in at 12.50'.
(2) Raising the site to provide additional elevation difference would become a costly
and cumbersome process for the majority of the Phase 3B drainage area. Much
of the upstream portion of this drainage area is already existing roadway
networks which serve as the primary entrance to the International Airport.

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b) Proprietary Underground Stormwater Control measures require frequent maintenance:
i) Requires quarterly inspections.
ii) Replace the filter media whenever it fails to function properly after maintenance.
c) Placing proprietary underground stormwater control measures in areas of high
sedimentation will reduce the lifespan of the filter cartridges. Devices can not be used for
sediment control during construction for erosion control.
d) No separation required between bottom of SCM and SHWT. However, proprietary
underground stormwater control measures placed in SHWT require anti -buoyancy
measure which also drives up cost.
e) Not Selected due to drainage area size, elevation requirement from flow into SCM to
invert out which is increased in a closed top system to provide space for routine
maintenance of the sand and costs of SCM and adding stormwater detention. Costs rise
further due to anti -floatation measures required.
17) Filter Strip:
a) Listed as "Med" under the Wildlife Habitat column within the 2017 MDC Guidance on
SCM selection.
b) The Level Spreader — Filter Strip is a Secondary SCM. Designed to work in conjunction
with another SCM.
c) See Proposed SCM Solution below
18) Treatment Swale (standard):
a) The 2017 MDC Section E-4 Airports Table 1 states: A treatment swale is a secondary
SCM; however, it may be used on an airport where a primary SCM is not feasible.
b) Listed as "Y" under the Works with Shallow Water Table column within the 2017 MDC
Guidance on SCM Selection. However, the specific MDC #1 states: Swales shall not be
excavated below the Seasonal High Water Table.
i) Swales with bottoms intersecting the SHWT may remain inundated with groundwater
during portions of the year and have insufficient volume available to treat runoff from

the design flow. They are also more prone to developing soggy bottoms a,
vegetation.
c) See Proposed SCM Solution below
Proposed SCM Solutions:
19) Overall items which apply to both proposed SCM types:
a) A key objective of the Plan is to address the North Carolina Stormwater Management
Rules (15A NCAC 02H.1000) administered by the North Carolina Department of
Environment and Natural Resources, Division of Water quality.
b) In the 2004 Stormwater Master Plan it was determined that stormwater management at
the Wilmington International Airport should be accomplished primarily with a combination
of extended dry detention basins and grassed swales needed to meet the required 85%
pollutant removal efficiency stipulated under North Carolina Stormwater rules.
i) The extended dry detention basins will also serve to meet the peak discharge
attenuation requirements of the New Hanover County Storm Water Management
Ordinance
ii) Since this time BMP regulations have been updated to the current 2017 MDC
requirements for SCMs.
c) Extended dry detention basins and grasses swales are specifically called for in the 2004
Stormwater Master Plan which was created as a planning tool for providing stormwater
management infrastructure in support of anticipated development activities on airport
property. Final design, supported by topographic survey, wetlands delineation, and
subsurface exploration efforts was left in the hand of the subsequent Engineers.
i) The 2004 Stormwater Master Plan does not specifically list any means of dealing
with SCM location which encounter flat topographic challenges.
ii) The 2004 Stormwater Master Plan does not specifically list a means of best
protecting Jurisdictional wetlands fed by existing drainage patterns.
iii) The 2004 Stormwater Master Plan does not specifically list any means of dealing
with SCM locations which encounter a high Seasonal High Water Table.
(1) The 2004 Stormwater Master Plan included concept sections for an Extended
Dry Detention Basin, on sheet D1.1, without listing a means of dealing with a
shallow Seasonal High Water Table.
d) Our SCMs were designed based upon the approved and existing SCMs from 2005,
2009, and 2012.
e) Extended Dry Detention basins and Grassed Swales were selected and designed to
minimize wildlife habitat and associated risks to aircraft safety.
i) Are listed as "Low" under the Wildlife Habitat column within the 2017 MDC Guidance
on SCM selection.
ii) The 2004 Stormwater Master Plan highlights the need for wildlife hazard issues to be
a primary design consideration. It included a careful review of FAA Advisory Circular
150/5200-33A, "Hazardous Wildlife Attractants On or Near Airports" and consulted
the USDA Wildlife Services to interpret the FAA criteria for context of local
conditions. Wildlife Services has advised that the Advisory Circular guidelines are
appliable at the Wilmington International Airport and recommends the use of

extended dry detention basins and grasses swales rather than wet detentions basins
at the airport.
f) Extended Dry Detention basins and Grassed Swales work in conjunction to provide
treatment and detention for the necessary storm events.
g) Low-cost SCMs selected based upon ILM Airport funding and used in conjunction with
other low-cost SCMs in a manner that meets or exceeds performance standards while
integrating them into the natural features of our site.
h) Extended Dry Detention basin can be used as a sediment basin during construction of
future impervious upon the ILM Business Park lots.
i) Extended Dry Detention Basin 3A is proposed to be utilized as a sediment basin
during Phase 1 of the erosion control plan.
ii) Extended Dry Detention Basin 3B is proposed to be utilized as a sediment basin
during Phase 2 of the erosion control plan.
iii) Option exists for these to be re -used as sediment basins in the future.
i) Ease of maintenance; no OSHA confined entry certification required to inspect or repair;
limited specialized equipment needed to perform maintenance.
j) NOTE: On the attached "Figure 6 — WTDM" delineation map, which was approved by
USACE, there are currently Jurisdictional Wetlands present in the two existing Grassed
Swales and the one Extended Dry Detention basin. Additionally, there are Jurisdictional
Ephemeral Stream channels present within the Extended Dry Detention basin. The
stream channel and wetlands likely extend further into the Extended Dry Detention basin
than our map illustrates since it abuts our delineation scope area limits.
i) One of the three criteria for wetlands is standing water being present at the surface.
(along with soil conditions and established vegetation).
(1) The placement of wetlands within the devices illustrates the SCMs were
designed as compliant devices in 2005, 2009, and 2012. However, through 2021
optics the SCMs appear to now be existing non -compliant devices which are in
good standing.
(a) Part of the Treatment Swale MDC description describes the current condition
well: Swales with bottoms intersecting the SHWT may remain inundated with
groundwater during portions of the year. They are also more prone to
developing soggy bottoms and wetland vegetation.
(2) With these existing devices being in good standing on the same parcel we
believe they are a valid basis of our design.
(3) Dry Detention basins, with outlet orifices set at the low point, will continue to
drain any groundwater which seeps into the devices. Our design does not include
any upstream splitters/weirs which would retain standing water.
ii) Nearby, wetland "F" if located at approximately the same elevation as our site, yet is
closer to the existing SCMs. Indicating the SHWT within the three existing devices is
higher than the delineated elevation of approximately 13.50' within the grassed
swales.
iii) Additional surface wetlands are present surrounding the Extended Dry Detention on
the 2009 Sheet P-2 "Existing Extended Dry Detention Basin No.1."

k) NOTE: Phase 3B has —1,275 LF of grassed ditches will be indefinitely retained. The
shortest is 235' of a continuous run. These grassed ditches provide some level of pre-
treatment for the existing roadway impervious along Airport Blvd and Gardner Road.
However, we have not tried to quantify or claim credit for these ditches.
y. dt
1
345'
I
20) Extended Dry Detention basin and Treatment Swale similar to 2004 Master Plan along with
the 2005 and 2009 design:
a) Listed as "Y" under the Works with High Sediment Input column within the 2017 MDC
Guidance on SCM Selection.
b) 2004 Stormwater Master Plan criteria for Extended Dry Basins:
(1) The basin should be steep -sided, narrow, and linearly -shaped.
(a) Basins are steep -sided, narrow, and linearly shaped.
(2) Capture the runoff from a 1" rainfall and release over a period of 48 hours.
(a) Phase 3A captures the runoff from the 1.5" rainfall and releases over a period
of 3.9 days
(i) NOTE: This increased release rate is due to NCDOT Hydro requirement.
(b) Phase 3B captures the runoff from the 1.5" rainfall and releases over a period
of 3 days
(3) Provide a minimum flow length -to -basin width ratio of 3:1.
(a) Phase 3A provides between a 3:1 to a 5:1 length -to -basin width ratio.
(b) Phase 3B provides approximately a 7:1 length -to -basin width ratio.
(4) Provide side slopes in the range of 3:1 to 4:1 (horizontal:vertial).
(a) Side slopes of 3:1 provided.

(5) Install outlet orifice in an enclosed structure with a sump. Provide a trash rack on
the inlet to the structure. Do not provide an open permanent pool.
(a) Outlet orifice provided in an enclosed structure with a sump. Trash rack
provided on inlet to riser structure. Open permanent pool not provided.
(6) Provide a rip -rap or concrete lined low -flow channel from inlet to outlet with a
minimum depth of one (1) foot.
(a) A 9" thick Class A rip -rap channel with one (1) foot of depth provided.
(7) Slope basin bottom at 2% preferred and 1 % minimum grade toward low flow
channel.
(a) Bottom of basins sloped at 1 % toward low flow channel.
(8) Provide heavy equipment access for clean -out and maintenance.
(a) Access provided for heavy equipment.
(9) Provide excess storage in the lower levels of the basin amounting to 20% of the
1" rainfall event runoff volume.
(a) Phase 3A and 3B provide storage to 25% of the 1.5" rainfall event runoff
volume
(10) Provide for peak flow attenuation above the 1" storm storage, in
accordance with the New Hanover County Storm Water Management Ordinance.
(a) Phase 3A and 3B provide peak flow reductions for the 1, 2, 10, 25, 50, and
100-year storm events above the 1.5" storm storage.
(11) Provide for seeding the basin bottom side slopes and berms with
common Bermuda grass or other appropriate mix. Seed mixture shall not contain
any form of millet, rye grass or other large seed producing grasses.
(a) Bermuda grass, Cynodon Dacty/on, is to be installed within SCMs per
Landscape Plans C6.0 and C6.1.
(12) Stabilize the basin within 14 day of construction completion.
(a) Basin to be stabilized within 14 days per note #6 of Erosion Control
Construction Sequence found on Sheet C4.2.
(13) To the extent possible, position the bottom of the basin above the
seasonal high water table.
(a) We acknowledge our proposed design elevation does go below the SHWT
we provided but the 2004 permit states "to the extent possible" and we are
meeting that requirement. The approved 2005 and 2009 Extended Dry
Detention basin is located nearby, under the same Master permit, and was
approved using a Seasonal High Water Table value of 6.0' which dates to the
original Extended Dry Detention basin design. Current field conditions now
include Jurisdictional wetlands within the Extended Dry Detention basin,
showing the Seasonal High Water Table, at the upstream end of the SCM,
exceeded the bottom elevation of the Extended Dry Detention basin (inlet
pipe outlet @ 10.83' and 10.26' per field survey conducted by Paramounte
Engineering Sheet dated 11/20/19). All evidence points to this device is in
good working order and is functioning as designed. Providing evidence that
our proposed alternate means of compliance in regard to the SHWT can also
meet the intent of the NCDEQ treatment regulations.

(b) The 2004 Stormwater Master Plan presents workable solutions for the long
term storm water management needs of the airport. Implementation of the
plan depends on the exact nature, magnitude, and sequence of development
projects which move forward and on funding resources which become
available for construction of stormwater solutions.
(i) Nature:
1. To provide permanent stormwater treatment for forthcoming
Commercial development within the ILM Business Park.
2. All told the permanent Phase 3A and 3B SCMs will allow -11.33
acres of development to proceed. The 11.33 acres include future
internal road. After the Circle K parcel is developed approximately 8
acres will remain.
3. Meaning the majority of the drainage (16.66 ac of the 27.99 acres) will
either be comprised of SCMs or existing right-of-way area along
Airport Blvd and Garner Road.
(ii) Magnitude:
1. Phase 3A and 3B drainage areas account for only -2.1 % of the
overall 1,338.95 acre parent parcel.
2. Or only -8.7% of the overall drainage area covered by permit SW8
050547.
3. The Phase I & II drainage areas currently have in excess of 3 Million
SF of impervious allocation for Future Development. Which is 2.4x
larger than the Phase 3A and 3B drainage areas combined.
(iii) Sequence: "Distributed" SCMs located near the outlet of the respective
drainage area. No future upstream or downstream devised are expected
to be placed in sequence with these devices.
(iv) Funding:
1. ILM Airport is solely funding the construction of the stormwater
devices.
2. ILM is cost -sensitive due existing budgets.
3. ILM is doing this construction in hopes of attracting additional
developers to enter the ILM Business Park by offering pad -ready sites
for development.
4. Current economic conditions, due to COVID, has greatly reduced
flight traffic which has directly reduced their income derived from gate
fees.
5. Long term maintenance costs must be factored into the front-end
design to ensure ILM is not saddled with expensive repairs on an
annual basis.
(c) The 2004 Stormwater Master Plan also states that nothing in this plan is
intended to limit or restrict the airport or its current or prospective tenants with
respect to pursing alternate of modified stormwater management solutions in
various locations.
(14) Provide for safe conveyance of a 100-year storm event.

(a) Extended Dry Detention basins designed to safely convey a 100-year storm
event.
c) NOTE: Draw down time for the Phase 3A Extended Dry Detention basin is limited by
NCDOT Hydrology Department which will not allow an increase in Post -flows for the 10,
25, 50, and 100-yr storms under N. 23rd Street.
21) Treatment Swale similar to 2004 Master Plan along with the 2012 design:
a) 2004 Stormwater Master Plan criteria for Grassed Swales:
(1) Swales will typically be located upstream of extended dry detention basin.
(a) Grassed swales placed directly upstream of extended dry detention basins.
(2) Provide a 0.2% minimum to 4.0% maximum longitudinal slope.
(a) Phase 3A longitudinal slope set at 0.10% due to elevation constraints.
(i) Note the previously approved Phase I & II grassed swales are both
designed at 0.03%
(b) Phase 3A longitudinal slope set at 0.20%
(3) Provide side slopes no steeper than 3:1 (horizontal:vertical) with 5:1 preferred.
The swale cross section should be triangular or parabolic.
(a) Side slopes of 3:1 provided and match the shape of the existing grassed
swales.
(4) Swale bottom should be located above the seasonal high water table
(a) The approved 2012 Pre -Treatment swales are located nearby, under the
same Master permit, and were approved using a Seasonal High Water Table
value of 6.0' which dates to the original Extended Dry Detention basin design.
This test was not completed with the devices. Current field conditions now
include Jurisdictional wetlands within these two pre-treatment swales.
Showing the Seasonal High Water Table exceeded the bottom elevation of
the pre-treatment swales (bottom @ 11.47' and 11.14' per Paramounte
Engineering Sheet C3.0 dated 1019/12). These devices are in good working
order and are functioning as designed. Providing evidence that our proposed
alternate means of compliance in regards to the SHWT can also meet the
intent of the NCDEQ treatment regulations.
(b) The 2004 Stormwater Master Plan presents workable solutions for the long
term storm water management needs of the airport. Implementation of the
plan depends on the exact nature, magnitude, and sequence of development
projects which move forward and on funding resources which become
available for construction of stormwater solutions.
(i) Nature:
1. To provide permanent stormwater treatment for forthcoming
Commercial development within the ILM Business Park.
2. All told the permanent Phase 3A and 3B SCMs will allow —11.33
acres of development to proceed. The 11.33 acres include future
internal road. After the Circle K parcel is developed approximately 8
acres will remain.

3. Meaning the majority of the drainage (16.66 ac of the 27.99 acres) will
either be comprised of SCMs or existing right-of-way area along
Airport Blvd and Garner Road.
(ii) Magnitude:
1. Phase 3A and 3B drainage areas account for only —2.1 % of the
overall 1,338.95 acre parent parcel.
2. Or only —8.7% of the overall drainage area covered by permit SW8
050547.
3. The Phase I & II drainage areas currently have in excess of 3 Million
SF of impervious allocation for Future Development. Which is 2.4x
larger than the Phase 3A and 3B drainage areas combined.
(iii) Sequence: "Distributed" SCMs located near the outlet of the respective
drainage area. No future upstream or downstream devised are expected
to be placed in sequence with these devices.
(iv) Funding:
1. ILM Airport is solely funding the construction of the stormwater
devices.
2. ILM is cost -sensitive due existing budgets.
3. ILM is doing this construction in hopes of attracting additional
developers to enter the ILM Business Park by offering pad -ready sites
for development.
4. Current economic conditions, due to COVID, has greatly reduced
flight traffic which has directly reduced their income derived from gate
fees.
5. Long term maintenance costs must be factored into the front-end
design to ensure ILM is not saddled with expensive repairs on an
annual basis.
(5) Swales should be designed for ready mowing with standard mowing equipment.
(a) Designed for mowing with standard mowing equipment.
(6) Flow velocity should be limited to 2 feet per second for the 2-year design flow
and a non -erosive velocity for the 10-year design flow.
(a) Phase 3A Grass Swale: 2-year velocity = 1.12fps; 10-year velocity = 1.22 fps
(b) Phase 3B Grass Swale: 2-year velocity = 1.31fps; 10-year velocity = 1.42 fps
(7) An attempt shall be made to provide 100 linear feet of swale per acre of drainage
area. No less than 50 linear feet of swale per acre shall be provided.
(a) The proposed Phase 3A swale is 150 LF in length and accounts for 4.89
acres of drainage area. Which equates to 30.67 LF per acre. The proposed
3B swale is 150 LF in length and accounts for 17.36 acres of drainage area.
Which equates to 8.64 LF per acre.
(i) By the 501f/ac criteria the Phase 3A swale should be no less than 244.5
LF in length.
(ii) By the 501f/ac criteria the Phase 3B swale should be no less than 868 LF
in length.

(iii) However, when compared to the existing Phase I and II grass swales our
proposed amount far exceeds what has been accepted in the past. Those
two grassed swales total 300 LF in length and handle 287.63 acres.
Which means they provide only 1.04 If/ac.
(iv) Based on the "decentralized" SCM locations within the ILM business park,
it is key to try and preserve as much developable area land as possible
while also complying with regulations. A quick calculation shows that a
42' wide swale (top of bank to top of bank), which is 1,112 LF long, would
encompass more than 1.07 acres of developable land. Thus eliminating
13% (1.07 ac / 8 ac) of the remaining developable land within Phase 3A
and Phase 3B.
(8) Provide for seeding the swale with common Bermuda grass or other appropriate
mix. Seed mixture shall not contain any form of millet, rye grass or other large
seed producing grasses.
(a) Bermuda grass, Cynodon Dactylon, is to be installed within SCMs per
Landscape Plans C6.0 and C6.1.
(9) Stabilize the swale with 14 days of construction completion.
(a) Basin to be stabilized within 14 days per note #6 of Erosion Control
Construction Sequence found on Sheet C4.2.
It is our professional opinion that the stormwater solution proposed meets the 2004 Stormwater
Master Plan based on the information provided above and the guidance provided by that permit.
In addition, we have extensively evaluated, in detail, many other SCM alternatives and found
the solution proposed to be the best alternative to provide stormwater treatment.
b. The 2004 approved "Stormwater Master Plan" document for this alternative design
indicates for grassed swales, that the "swale bottom should be located above the
seasonal high water table". The proposed design, however, appears to position the
bottom of the swales below the seasonal high water table. It is understood that a clay
liner is proposed, however, it is my understanding that clay liners are more effective
at keeping water in than keeping water out. The grassed swale requirements of the
"Stormwater Master Plan" do not make the same "to the extent possible" distinction
as the dry detention basin requirements. Please confirm the intended design and
ensure this requirement for the alternative design is met.
Response: Based upon further discussion with our Sr. Geotechnical Engineer we
have removed the clay liner from our design. His experience has been that clay
liners are equally effective in keeping water in a device as out of a device however,
constructability concerns in this location and long term potential uplift have caused
us to reevaluate and therefore remove clay liners from the design. Similarly, a
synthetic liner has also not been chosen. This evaluation of the design also includes
all available evidence pointing to the existing stormwater control system functioning
properly and in good order and therefore our proposed design providing an equal
level of treatment meeting the 2004 design criteria.

2. 15A NCAC 02H.1042(2)(a): The signatures provided on the submitted application,
operation and maintenance agreements, and proposed deed restrictions and protective
covenants were all copies. These documents must include an original signature. The
response letter included with the January 21, 2021 resubmittal indicated that "We remain
in the process of obtaining the original signed documents and will provide upon receipt."
The originally signed documents, however, were never received. Please provide an
original signature for all documents that require the applicant's signature.
Response: Original Signatures on the O&M agreements have been provided under
different cover letter.
3. 15A NCAC 02H.1042(2)(a)(iv):
a. In order to ensure the SWU-101 form remains consistently updated and represents
the entire permitted condition, Section IV.10 of the application must reflect all
drainage areas covered in this permit, including the Phase I & II drainage areas.
Please update Section IV.10 of the application to reflect all drainage areas permitted
under SW8 050547.
Response: The phase 1 & 2 drainage areas have now peen included on the SWU-
101 form.
b. Drainage Area 3C in Section IV.10 of the submitted application indicates that there is
312,094 square feet of "other on -site" built -upon area (BUA) and 129,628 square feet
of "future" BUA, however, there is no proposed SCM(s) to treat this proposed BUA. It
is noted that there is some existing BUA. Please confirm one of the following, provide
additional explanation and update the application package appropriately:
i. No SCM is proposed for Drainage Area 3C at this time and no BUA is
proposed beyond the existing BUA; or
ii. A new SCM is proposed to treat Drainage Area 3C and the application is
being revised to include the SCM; or
iii. Drainage Area 3C is an area of low density and the application package will
be revised to include this area of low density;
Response: Phase 3C drainage area numbers have been revised to remove "future
impervious." No SCM is proposed for DA 3C at this and no BUA is proposed beyond
the existing.
c. Section IV.7 of the application indicates that the total project area covered under
SW8 050547 is 27.99 acres. SW8 050547, however, currently has an approved total
project area of 322.3 acres. Please confirm the correct total project area and ensure
it is represented consistently throughout the entire application package.
Response: Our application has been updated to reflect the entire 322.3 acres per
the original permit. We are now showing on our application Phase I, II, and III.

4. 15A NCAC 02H. 1 042(2)(g): The submitted drainage area plan sheet does not clearly
show the proposed Drainage Area 3C. In order to support the entire previously approved
Phase III area is covered by this modification, please include the entire area on the
drainage area plan sheet and clarify the proposed Drainage Area 3A, Drainage Area 3B
and Drainage Area 3C.
Response: DA3.0 has been revised to now include Drainage Area 3C, now shown with
a transparent hatch.
5. 15A NCAC 02H. 1 042(2)(f) and .1042(2)(a)(iv): The calculations for Extended Dry
Detention Basin 3A indicates that the total impervious area draining to the basin is 1.67
acres (72,746 square feet). Section IV.10 of the application, however, indicates there is
116,598 square feet of BUA proposed in drainage area 3A. Please confirm the correct
amount of BUA proposed in drainage area 3A and ensure it is represented consistently
throughout the entire application package.
Response: The impervious area draining to extended dry detention basin 3A is 2.67
Acres. The calculations have been updated and the impervious area is now consistent.

Storm Water Impact Analysis
Circle K — NTI Airport Blvd Wilmington — NC.115
Airport Boulevard
Wilmington, NC 28405
(PID: R04200-001-025-F00)
Prepared by:
TIMMONS GROUP
Project #:
37630.054
Date:
8/27/2020
Revised:
1 /19/2021, 03/26/20210
.1
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a4 9f
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f: I M ON S GROUP
"eUP VISION ACHIEVE® TWIROUR"N G1J;k1

Table of Contents:
1. Cover Sheet
2. Table of Contents
3. Project Narrative
4. Reference Material:
a.
USGS Map
b.
Soil Survey Map
c.
FEMA FIRM Map
d.
NOAA Rainfall Data
e.
Pre -Development Drainage Area Map
f.
Post -Developed Drainage Area Map
g.
SHWT & Infiltration Test Report
5. Peak Flow Analysis
a. Table of Subareas, Land Uses, Curve Numbers, & Time of Concentration
b. Peak Flow Summary
c. Hydraflow Report
6. Water Quality Calculations
a. Stormwater Grass Swale Calculations
b. Stormwater Extended Dry Detention Pond Calculations
c. Stormwater Supplement Forms
7. Stormwater Operation & Maintenance Agreement
8. Miscellaneous Calculations
a. Storm Pipe HGL Calculations
b. Spillway Calculations
c. Energy Dissipater Calculations

PROJECT NARRATIVE
L

Project Data:
Project Name: Circle K — NTI Airport Blvd Wilmington -- NC.115
PID: R04200-001-025-F00
Project Address: Airport Blvd, Wilmington, NC 28405
Stormwater Basin: Smith Creek
River Basin: Cape Fear
Water Classification: C;Sw
Site History:
The existing parcel is owned by New Hanover County and is controlled by Wilmington International
Airport. This property is part of an overall airport stormwater master plan, and was previously permitted
with NCDEQ under SW8 050547 — Phase III. The current Wilmington International Airport Stormwater
Master Plan include a proposed Phase 3 expansion to the existing Extended Dry Detention Basin to the
east of our proposed Circle K site, which was intended to accommodate future build -out of the
undeveloped Phase 3 properties. The Phase 3 Extended Dry Detention Basin Expansion was never
constructed. Many of the Phase 3 drainage areas remain undeveloped at this time, and they do not
actually drain into the existing extended dry detention basin at this time.
Project Description:
The project proposes a gas station/convenience store, associated parking lot, canopy, driveways, and
utilities. The project is proposing shared access roads connecting to both N. 23rd Street and Airport Blvd,
as well as water/sewer extensions to serve future developmcnt in adjacent land.
This project is a proposed modification to the current 2011 SW8 050547 — Phase III stormwater permit.
Two extended dry detention basins are proposed. Refer to the proposed conditions section below for
additional information.
Existing Conditions:
Refer to the pre -development drainage area map in this report. The study area represents a portion of
the previously permitted Phase III drainage area.
DA 1.1 consists of 4.53 acres of mostly undeveloped lawn and some woods. This drainage area also
includes impervious surfaces from portions of Airport Blvd and N 23rd St. This drainage area runs
through an existing roadside ditch, and into an existing 24"RCP culvert under N 23rd Street, and
discharges to the southwest.
DA 1.2 consists of 4.62 acres of undeveloped lawn and woods. This drainage area surface discharges,
and enters another existing 24"RCP culvert under NC 23rd Street, and discharges to the southwest.
L
L

DA 1.3 consists of 15.47 acres of mostly undeveloped lawn and woods. This drainage area includes
impervious from portions of Airport Blvd, Gardner Road, and an old gravel service drive. This drainage
area runs through existing roadside ditches, culverts, and wetlands channels before it surface discharges
to the south.
DA 1.4 consists of 1.85 acres of offsite undeveloped lawn. This drainage area runs through an existing
roadside ditch and into an existing 24" RCP culvert under N 23rd St, which discharges to the southwest.
All drainage from this area enters Smith Creek, which is roughly —0.42 miles south of our project area.
Smith Creek flows east which eventually enters the Northeast Cape Fear River approximately —1 .62
miles to the west.
The Soils Survey map shows that the soils on site are as follows:
SOIL TYPES:
SYMBOL
RATING
UNIT NAME
JO
D
JOHNSTON SOILS
Le
B/D
LEON SAND
Pn
B/D
PANTEGO LOAM
Se
A/D
SEAGATE FINE SAND
*Soil rating are based on NCDEQ Erosion and Sediment Control Planning and Design Manual —
Chapter 8 — Appendices
A copy of FEMA FIRM map 3720312900K, effective date 08/28/2018, included confirms that there is
no regulatory floodplain on the property.

Post -Developed Conditions:
Refer to the post -development drainage area map in this report.
DA 2.1 (Bypass):
This drainage area is 2.04 acres and predominantly consists of existing impervious from Airport Blvd
and NC 23rd Street right-of-way, as well as a proposed NC 23`d Street widening required by NCDOT. A
roadside ditch along Airport Blvd has been regraded to reduce drainage to Analysis Point A. This area
has been redirected to our Phase IIIB pond. This drainage area also consists of lawn/shoulder areas in
and adjacent to the public rights -of -way. This drainage area flows through an existing roadside ditch,
and into an existing 24" RCP culvert under NC 23rd Street, which is consistent with the existing
condition.
DA 2.2 — Stormwater Phase IIIA:
This drainage area is 4.89 acres and includes the following proposed improvements: Circle K
development, portions of several common drives, one grass pre-treatment swale, and one extended dry
detention basin. This Phase IIIA extended dry detention basin will be constructed by Circle K,
simultaneous with the Circle K project, but it will be a regional stormwater SCM located on New
Hanover County property but controlled and operated by Wilmington International Airport. Proposed
impervious areas will be collected to the extent practical in the SCMs, and will discharge into an
existing 24" RCP culvert under NC 23rd Street to the southwest, which is consistent with the existing
condition.
The Phase IIIA SCMs are designed to accommodate the below impervious allocation for Phase IIIA
drainage area at buildout:
Phase IIIA Circle K & Common Drives Proposed Impervious: 69,896 SF
Phase IIIA Potential Future Development: 46,702 SF
Phase IIIA Total Impervious Allocation: 116,598 SF (Includes potential future development)

DA 2.3A & 2.3B — Stormwater Phase IIIB:
This drainage area is 17.36 acres and includes impervious portions of existing Airport Blvd and Gardner
Road rights -of -way, lawn/shoulder areas in and adjacent to the public rights -of -way, as well as currently
undeveloped land on the south side of Airport Blvd. The following improvements will be constructed
with the Circle K project, which are located in Phase IIIB:
• A portion of a common internal drive.
• A left turn lane on Airport Blvd (required by NCDOT).
Phase IIIB includes one proposed grass pretreatment swale and one proposed extended dry detention
basin. The stormwater will discharge to the south, which is consistent with the existing drainage pattern.
The Phase IIIB SCMs are designed to accommodate the below impervious allocation for the Phase IIIB
drainage area at buildout.
• Phase IIIB Existing Road Impervious: 95,932 SF
• Phase IIIB Road Improvements to be constructed with Circle K: 7,633 SF
• Phase IIIB Potential Future Impervious Allocation: 264,031 SF
• Phase IIIB Total Impervious Allocation: 367,596 SF (includes potential future development)
DA 2.3C— (Bypass):
This drainage area is 0.51 acres of lawn area to the southeast of the proposed dry pond, which discharges
to the south.
DA 2.4 — (Bypass):
This drainage area is 2.02 acres and predominantly consists of existing NC 23rd Street public right-of-
way and undeveloped lawn to the south. This drainage area flows through an existing roadside ditch,
and into an existing 24" RCP culvert under NC 23rd Street, which is consistent with the existing
condition.

Stormwater Management Requirements:
i . New Hanover County Stormwater Design Manual:
• Detention: 2, 10, 25-yr storms
• Retain the 1.5-inch volume and drawdown in 2 to 5 days
2. NCDEQ - 15A NCAC 02H .1005 Stormwater Requirements: Coastal Counties
• High Density Option
• Retain runoff from 1.5-inch rainfall, drawdown in 2 to 5 days
• Design for ultimate buildout of the drainage area
• Alternative Design Criteria:
o 85% TSS removal
o Detain 1-year, 24-hr storm
Wilmington International Airport Stormwater Master Plan Approved Engineering Report,
Dated 10/26/04 by Talbert & Bright):
• Requires the use of "alternative stormwater management systems", which do not attract
wildlife, which would be a hazard to aircraft. Intended SCMs include grass swales in
series with extended dry detention basins.
• SCMs, which generate a permanent pool are prohibited for reasons of airport safety.
Proposed Stormwater Mana eg ment:
✓ Volume Control — The proposed stormwater extended dry detention basins will retain the 1.5-
inch volume for the net increase of impervious surfaces and release it over a 2-5 day period.
✓ Peak Flow Detention (1, 2, 10, 25, 50, 100-yr) — The proposed stormwater extended dry
detention basins will reduce peak flows for the 1, 2, 10, 25, 50, and 100-year, 24-hr storm events
down to below pre -developed levels, except as mentioned below. Refer to the Peak Flow
Summary Table for pre- and post- flows for all storm events
✓ Alternate Stormwater Management Systems — This project utilizes two pretreatment grass swales
and two extended dry detention basins. These SCM types were selected for the following
reasons:
a. These SCM types are required by the Wilmington International Airport Stormwater
Masterplan.
b. Other SCM types, which have permanent pools of standing water, are prohibited by the
airport and the FAA, because they attract wildlife, which would be a hazard to airplane
safety.
c. There is a precedent for selecting these SCM types, which exist just to the east of our
project.

Methodology:
The SCS unit hydragaph method has been used for project hydrology, implemented using Hydraflow
software. Time of concentration calculated using the TR-55 segmented approach. Rainfall data was
input based on the NOAA rainfall data. The hydrologic soil groups for the various soil units on the
airport were taken from the Appendix A listing of TR-55. The SCS soil map for New Hanover County
was used to identify soil units. For soils with multiple hydraulic soil groups, the lowest (most well
drained) group was used. The SCS type III 24-hour rainfall distribution was used. Pipeline hydraulic
grade lines were computed using Hydraflow software as well.
Summary of Results:
Refer to the following tables in this report to view the results data:
• Table of Subareas, Land Uses, & CN.
• Peak Flow Summary Table
• Stormwater Grass Swale and Extended Dry Detention Pond Calculations
As shown in the aforementioned tables in this report and plans, NCDEQ, New Hanover County, and the
Airport's Stormwater Master Plan requirements are satisfied.
Conclusions:
Through the use of two proposed stormwater pretreatment grass swales and two extended dry detention
basins, this project meets or exceeds NCDEQ/New Hanover County/ILM Stormwater Master Plan
requirements listed in the publications below:
• New Hanover County Stormwater Design Manual:
• NCDEQ - 15A NCAC 02H Stormwater Requirements: Coastal Counties
• Wilmington International Airport Stormwater Master Plan Approved Engineering Report,
Dated 10/26/04 by Talbert & Bright):
Phases IIIA and IIIB were designed to incorporate proposed and future development and resulted in
decreased flows for the 1, 2, 10, 25, 50, and 100-year, 24-hr storm events.
L

REFERENCE MATERIAL

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Appendices
Table 8.01d (continued)
Name
Depth
pH
K
Hydrology
Plasti-
_ ._--Textural
---------------
Classlflcation'---------
---------
Group
city
USDA
Unified
AASHTO
JOHNSTON
0-30
4.5-5.5
0.17
L
2-14
MK-L
OL, ML, CL-ML
A-8, A-4,A-5
0-30
4.5-5.5
V.20
C
NP-10
L, SL. FSL
ML. SM
A-2- A-4
30-34
4.5-5.5
0.17
11
JP
SR-S-S
SM, SP-SM
A-2, A-3
34-60
4.5-5.5
0.17
D
'NP-10
SR-FSL-SL
SM
A-2. A-4
xl' 1':A
0-14
4.5-6.0
0.15
B
'NP
LS, LFS
SM, SM-SC, SC
A-2
0-14
4.5-6.0
0.20
B
NIP-10
SL. FSL
SM. SM-SC, SC:
A-2. A-4
14-32
4.5-5.5
0.24
B
4-15
SCL
SC, SM-SC
A-2, A-4. A-6
3^-60
4.5-5.5
0. i O
B
NP
LS, S
SM, SP-SM, SP
A-2, A-3
KENANSVILLE
0-24
4.5-6.0
0.15
A
NP
LS, LFS
SM, SP-SM
A-1, A-2
0-24
4.5-6.0
015
A
NP
FS. S
SM; SP-SM
A-2; A-2
24-36
4.5-6.0
0.15
A
NP-10
SL, FSL
SM, SC, SM-SC
A-2, A-4
36-80
4.5-6 0
010
A
NP
S. LS
SP-SM, SM
A-1; A-2, A-3
KERSHAW
0-80
4.5-6.0
0.10
A
NP
S, COS, FS
SP, SP-SM, SW
A-2, A-3
KINSTON
0-12
45-6.0
024
B/D
NP-10
FSI.
SM. SC SM-SC
A-2. A-4
0-12
4.5-6.0
0.37
B/D
4-15
L, SIL
ML, CL, CL-ML
A-4, A-6
] 2 60
4 5-5.5
0.32
B-D
8-22
L, CL, SCL
CL
A-4. A-6, A-7
60-72
B/D
NP
Var
K1,R1- B
0-80
4.5-7.3
010
A
NP
S. COS. FS
SP, SP-SM
A-3
LAKELAND
0-43
4.5-6.0
0.10
A
NP
S, FS
SP-SM
A-3, A-2-4
43-80
4.5-6.0
0.10
A
NP
S; FS
SP SP-SM
A-3,A-2-4
LEAP
0-9
3.6-5.5
0.32
D
5-15
SIL, VFSL
ML, CL
A-4, A-6
0-9
3.6-5.5
028
D
5-12
FSI . I
ML
1-4, A-6
9-72
3.6-55
0.32
D
20-38
SICL. SIC. C
CL, CH
A-7
LEAKSI'II LE
0-9
5.1-6.5
0,43
D
6-10
STL„ I:; SIFT,
ML, 0-ML
A-4. A-6
9-18
6.1-7.8
0.24
D
35-75
CL, C, SIC
CH
A-7
18-24
61-7 8
024
D
20-45
CI.; SICL
0- CH
A-'
24-30
D
WB
30
D
CIWB
LENO5P,
0-8
4.5-5.5
0.37
D
11-10
L, SIL, VFSL
ML, CL, CL-ML
A-4
8-75
4.5-5.5
032
D
11-35
C. Sic, CI.
C`L. CH
A-6,A-7
LEON
0-15
3.6-5.5
0.1f)
B/D
'DTP
S, FS
SP, SP-SM
A-3, A-2-4
15-30
3.6-5.5
0.15
B/D
NP
S. FS, LS
SNf, SP-SM, 5P
A-3: M24
30-80
3.6-5.5
0.14
B/D
NP
S, FS
SP, SP-SM
A-3. A-2-4
LIDDELL
0-8
4.5-5.5
0-0
BD
2-10
L, SIL. VFSL
ML, CL-TVM
A-4
8-65
4.5-5.5
0.43
B;D
2-10
L, SIL. VFSL
ML, CL-ML
A-4
LILLINGTON
0-16
4.5-6.0
0.15
B
NP
GR-LS, GR-SL
firm, CiP-GM; SM,
A -I A 2
SP-SM
16-44
4.5-5.5
0.15
B
NP-10
GR-SCL, GR-CL
GM, GC, SM, SC
A-1, A-2, A-4
44-80
4.5-5.5
0.10
B
NP
SR-GRV-LS-GRV SCL
GM. SM
A-I,.A-2
LOCKIIART
0-6
5.1-6.5
0.15
B
NP
GR-LS, GR-SL
GM, GP -GM, SM,
A-1, A-2
SP-SM
6-54
5.1-6.5
0.17
B
5-15
GR-SCL; GR-L
GC. GM -GC, SC,
A2 A-4, A-6
SM-SC
54-72
B
Var
I.OUISA
04
4.5-6.0
0.17
B
N-P
GR-1- GR-SL, GR-FSL
SM
A-1. A-2..A-4
0-4
4.5-6.0
0.28
B
NP
L_ SL, FSL
SM, ML
A-2. A-4
4-15
4.5-6.0
024
B
NTP
GR-L; GR-SL
SM
A-2. A,4
15-60
B
WB
L01UISBLRCi
0-7
4.5-6.0
010
B
NP
LS. LCOS
SM
A-2. A-1-8
0-7
4.5-6.0
0.24
B
NP-6
SL, FSL
SM. SM-SC
A-2
7-24
4.540
024
B
?qp-,7
SL
SM, SM-SC
A-2. A-4
24-60
B
WB
'See Tables 8.01 b, 8.01 c and Figure 8.01 d for definition of symbols.
8.01.23

I
Appendices
Table 8.01d (continued)
Name Depth pH K Hydrology Plasti- - —. Textural Classification
Group city
USDA Unified AASHTO
R-Ac7L'LU
0-40
4.5-6.0
0. •;i
AT
NP
40-80
4.5-5.5
O R;
A'(
NP
PAMLICO
0-30
3.6-4.4
D
NP
30-60
3-6-5.5
0.m
0
NP
PAN-TF(X)
0-18
3.6-5.5
0.;19
B D
:YP-10
0-18
3.6-5.5
0.15
BiD
I P-10
0-18
3.6-5.5
0,110
R'D
NP
18-42
3.6-5.5
0.2*
BiD
4-16
42-65
3.6-5.5
0.2'«
BD
'1-24
2'AWVJ0Tr'yNK
0-17
4.5-6.0
043
BD
.NP-7
17-56
4.5-5.5
0.4"
B D
NP-7
56-80
4.5-5.5
032
BfD
NP
PELHAM
0-27
4.5-5.5
0.10
B/D
NP
0-27
4 5-5 5
010
BrD
NP
27-56
4.5-5.5
0.24
B/D
2-12
56-68
4 5-5.5
0.24
130
5-20
PENDER
0-13
4.5-6.5
0.24
C
NP-14
0-13
4.5-6.5
0.15
C
NIP-10
13-54
5.6-7.3
0.24
C
4-20
54-62
C
PENN
0-8
3.6-5.5
0.32
C
0-8
3.6-5.5
028
C
8-21
3.6-6.0
0.24
C
1-10
21-34
5.1-6.5
024
C
3-10
34
C
PE.RQUIMANS
0-8 -
4.5-6.5
0.37
D
NP-7
8-50
4.5-6.0
0.43
D
8-30
50-62
4 5-6.0
0.37
D
NP-7
PETTIGREW
0-15
3.6-5.5
B/D
NP
15-26
3.6-55
017
130
11-25
26-50
3.6-5.5
0.32
B/D
20-40
50-74
5.6-7,8
BID
PINKSTON
0-8
4.5-6.5
0.32
B
NP-10
0-8
4.5-6.5
0.3=
B
NP-10
8-19
4.5-5.5
0.24
B
NP-10
19-26
4.5-5.5
024
B
3-15
26
B
PLl:MMER
0-50
3.6-55
010
BID
NP
50-72
3.6-5.5
0.15
B/D
NP-10
POCALLS
0-23
4.5-6.5
0.15
A
IN
23-36
4.5-5.5
0.10
A
NP-4
3& 46
4.5-5.5
O l n
A
NP
46-72
4.5-5.5
0.15
A
3-15
POCOMOKE
(1-28
3.6-5.5
028
B'D
3-10
28-40
3.6-5.5
0.20
B/D
NP-8
POMFLLO
0-42
4 5-61)
010
C'
N'P
42-64
4.5-6.0
0.15
C
NP
64-80
4.5-6.0
0.10
C
INP
PONZER
0-24
3.6-4.4
D
NP
24-52
3.6-6.5
024
D
NP-10
52-72
D
'See Tables 8.01 b, 8.01 c and Figure 8.01 d for definition of symbols
LS, LFS, S
S, LS, LFS
MUCK
I.S. S; I,F:S
MK-L
L, FSI.; SL
LFS. LS
SCL, SL; CL
CL, SC, SCL
SIL. L, VFSL
L, VFSL, SIL
LS, I.FS, FS
LS
S. FS
SCL, SL
SCL, SL, SC
SL, FSL
LS.LFS
SL, SCL., CL
Var
SIL, L
SH-SIL, SH-L
SH-SIL, SH-L, SH-SICL
SH-SIL, SI3VI
UWB
SIL, L, VFSL
L, SICL, CL
SIL, L, SL
MUCK
L; CL, SICL
CL, C, SIC
Var
FSL, SL
SIL, L. VFSL
L, SL, SIL
GR-SL. L. SIL
WB
S. FS LS
SL, SCL, FSL
S, LS
SL
S. LS
SCL. SL
SL. FSL, LS
LS, S
COS, S. FS
COS. S, FS
COS, S. FS
MUCK
L. SCL, STL
Var
SM
A-2
SP-SM, sM
A-2; .A-3
PT
S11A, SP-SM
A-2. A-3
CL, SM, ML,
SM-SC
A2, A-4
SM. SM-SC, at
111
A2; A-4
SM
A-2
SC, C-L. SM SC.
CL-hill
A-4..A-6, A-2
CL, SC
A-6, A-7
CL ML, ML
A4
CL-ML, ML
A-4
SM.. SP-SM
A-2
SM
A-2
SM
A-2
SM. SC, SM-SC
A-2, A-4, A-6
SC. SM-S(', ML.
A-2. A-4, A-6,
CL
A-7
SM, SM-SC, SC
A-2
SM SP-SM
A 2
SC, SH-SC, CL,
CL-ML
A-2, A-4, A-4
ML
A-4
ML; GM
A-4
ML, SM, GM
A-4, A-2
ML. CL, SM, GM
A-4. A-2, A-1
ML, CL-ML
A-4
CL
A-4, A-6, A-7
ML. CL-ML
A-4
PT
CI.
A-6, A-7
CL, CH
A-7
CL, ML, SM, SC
A-2, A-4
Cl.... ML: SM-SC
A-4
SC, CL, ML, SM
A-2, A-4, A -I
(A., GM; C P-GM. .
A-1, A-2: A4
ML
A-6
SM. SP-SM
A-2-4. A-3
SM, SC, SM-SC
A-2-4, A-2-6,
A-4
SP-SM, SM
A-2, A-3
SM
A-2
SP-SM, SM
A-2, A-3
SM-SC, SC. SM
A-2, A-4, A-6
SM; SC, CL-ML
A-2, A-4
SM. SP-SM
A-2, A-3
SP SP-SM
A-3
SP- SM, SM
A-3, A-2-4
SP, SP-SM
4-3
PT
SM, ML. SC, CL.
A-2, A-4. A-6
8.01.27

Table 8.01d (continued)
Name Depth pH K Hydrology Plasti-
Group city
RUSTON
0-16
4.5-6.5
0.15
B
NP-3
0-16
4.5-6.5
028
R
NP-3
0-16
4.5-6.5
0.20
B
NP-3
4147
4.5-6-1)
0.32
B
NP-7
47-80
4.5-6.0
Orx
B
1-20
SCRAN1, i"e
0-7
4.5-6.5
0.15
A v
NP
0-7
4.5-6.5
O.Li'
AID
'YP
7-41
4.5-5.5
0.33v
LLD
NIP
41-72
4.5-5.5
0.10
A`*D
NP
SEh k- !? f t K
(1-4
4.5-6.5
0.Wc
C"
-NP
9-60
4.5-6.5
0.a4:
C
NP
SLAG i ;Fl.
0-12
3 6-6V
0.11)
AID
NP
12-28
3.6-6.0
0.15
Ali?
NP
28-36
3.6-6 0
0 w
Alt)
NP
36-40
3.6-6.0
02�
A/D
NP-7
40-64
3.6-6.0
0.32
A/D
116-27
SED3GEFIELD
0-13
4.5-6.5
0.17
C
NP
0-13
4.5-6.5
0
C
5-20
13-33
4.5-6.5
0 ?k
C
25-60
33-37
5.0r8.1
028
C
8-25
37-65
C
S'LALLING5
0-12
3.6-5.5
010
C
NP
0-12
3.6-5.5
0.20
C
NP-3
12-42
3.6-5.5
0.17
C
NP-3
42-80
3.6-5.5
0.17
C
NP-4
ST.ARR
0-10
5.1-6.5
024
C
NP-7
0-10
5.1-6.5
0.28
C
3-12
0-10
5.1-6.5
028
C
3-23
10-53
5.1-6.5
0.28
C
3-23
53-70
5.1-6.5
0.28
C
NP-15
STATE
0-10
4.5-5.5
0.28
B
NP-7
0-10
4.5-5.5
0.38
B
NP-15
0-10
4.5-5.5
0.28
B
NP-6
10-45
4.5-55
0.28
B
8-22
45-60
4.5-6.0
0.17
B
NP-7
STONEWLI.E
0-5
4,5-6.0
032
B
6-16
5-13
4.5-6.0
0.32
B
11-25
1.3-38
4.5-6.0
028
B
20-50
38-48
4.5-6.0
0.24
B
11-31
48-72
B
SUNCOOK
0-7
4.5-6.5
0.17
A
NP
7-42
4.5-6.5
017
A.
NP
42-60
4.5-6.5
0.10
A
NP
TALI ADEGA
0-9
4.5-55
028
C
NP-111
0-9
4.5-5.5
0.32
C
NP-10
9-22
4.5-5.5
028
C
8-15
22-26
C
26
C'
'See Tables 8.01 b, 8.01 c and Figure 8.01 d for definition of symbols.
Appendices
-------------------Textural Classification' ---
USDA Unified
----------------- ---
AASHTO
GR-FSL, GR-SL, GR-L
SM
A-2, A-1-B
F;SI., ST,
SM, ML
A-4, A-2-4
LFS
SM
A-2-4
FSL, SL, LS
SM. ML, CL-NIL;
A4..A-2-4
SM-SC
SCL, L, CL
SC, CL
A-6
LS, LFS
SM. Sp-SM
A-2, A4
S, FS
SP-SM, SM
A-2, A-3
LS, S., FS
SP-SM SM
A-2, .A-3
S. FS
SP-SM, SM
A-2, A-3
IFS, L-S; FS
SM, SP-SM
A-2. A-3
LFS, FS, S
SM. SP-SM
A-2, A-3
FS.. 5
SM. Sp-SM
A-2..A3
FS, LFS, S
SM. SP-SM
A-2
FS, S
SM, Sp-SM
A-2, A-3
SL, SCL
SM- SM-SC
A-2, A-4
Cl., SCL
CL
A-6, A-7
LS
SM
A-2
FSL, SL, SCL
SM, SM-SC, CL
A-2, A-4, A-6
SC, CL.. C
CL, CH
A-7
SL, SCL, CL
SC, CL
A-6. A-7, A-4
UWB
LS, LFS. FS
SM
A-2
SL, FSL
SM
A-2, A4
SL•, FSL
SM
A-2, A-4
SL, LS, LFS
SM, SP-SM,
A-2, A-4
SM-SC
SL; FSL
SM. SM-SC
A-4. A-2
L
ML, CL-ML, CL
A-4, A-6
SIL, SICL. Sft
ML, CL-ML, CL
A-4, A-6, A-7
CL, SCL, SICL
ML, CL-ML, CL
A-4, A-6, A-7
GR-ST., SCL, CL
SM, SM-SC, SC
A-2; A-4.. A-6
FSL, SL
SM, ML CL-ML.,
A-2, A-4
SM-SC
SIT,, L
CL M. SC; ML,
A-4, A-6
LS, LFS
SM: SM-SC
A-2. A-1
I, CL. SCL
CL. SC
A-4, .A-6
SR-S-FSL
SM, SM-SC,
A-1, A-2, A-3,
SP-SM
AA
L., STT.:, C L
SM-SC , CL. ML,
A-4, A-6
CL-ML
CL, SICL, L
CL
A-6, A-7-6
C, CL, SIC
CL, CH. MH
A-6, A-7
CL, SICL, L
CL. MH, ML
A-6, A-7
WB
LFS, LS, SL
SM
A-2
SR-I.FS-C'OS
SP sm
A-2..A-3
SR-LFS-GR-COS
SP, SM
A-1_ A-2, A-3
CN-SIL, CN-1-
Sm— SC, SM-SC,
AA- A-1 A-1
Gm
SIL, L
SM, SC, ML,
A-4
SM-SC.
C's-CL; CN-SIL, CN-SIC I,
(M: 0C, SC. SM
A-4. A-6, A-2
Vat
WB
8.01.29

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D

2/12/2020 Precipitation Frequency Data Server
9eNOAA Atlas 14, Volume 2, Version 3
Location name: Wilmington, North Carolina, USA*
Latitude: 34.2669", Longitude:-77.9209*
Elevation: 24.99 ft** ��
"source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, FA.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 ,
Duration
Average recurrence Interval (years)
F7k7F
100
T 200
500
0000
0.521
(0.488-0.560)1(0.578-0.664)1(0.677-0.776)
0.618
0.724
0.808
(0.751-0.866)1(0.846-0.976)1(0.914-1.06)
0.913
0.991
1.07
(0.984-1.15)
1.15
1.05-1.24)
1.26
1.13-1.35)
1.34
(120-1.44)
I�5-min
0.833
0.989
1.16
1.29
1.45
1.58
1.71
1.83
1.99
2.11
10-mtn
0.780-0.895)
(0.925-1.06)
1 (1.08-1.24)
1.20-1.39)
1 (1.35-1.56)
(1.46-1.69)
(1.56-1.82)
l(1.67-1.96)
(1.79-2.14)
(1.89-2.27
104
1.24
1.47
1.63
1.84
2.00
2.15
2.31
2.50
2.65
15-min
(0.975-1.12)
1.16-1.34
(1.37-1.57)
(1.52-1.75)
1.71-1.97
(1.84-2.14)
(1.98-2.31)
(2.10-2A7)1(2.26-2.69)
2.37-2.85)
30-min
1 344353)
1.61 1?84)
(1. 5 2924
2.2 2754)
2.53 2392)
2.78-3 22)
3.03 3053
(3.27 3985)
(3. 9-4 28)
(3.84 4962
1.78
2.15
2.67
3.08
3.64
4.08
4.55
5.04
5.71
6.27
60-min
(1.67-1.91)
2.02-2.31)
1 (2.50-2.87)
1 (2.87-3.31)
3.37-3.89)
(3.764.37)
(4.17-4.87)
(4.59-5.40)1(5.15-6.14)
(5.61-6.74)
2.10
(1.94-2.30)
2.56
(2.36-2.79)
3.27
(3.01-3.56)
3.86
](3.55-4.21)
4.73
(4.33-5.14)
5.48
(4.99-5.95
6.30
(5.70-6.84)
7.2D
(6.47-7.80)
8.54
9.69
8.55-10.6)
IED2-hr
2.25
2.73
3.50
4.77
5.18
6.0B
7.05
8.15
(7.59-9.27)
9.84
11.3
i 3-hr
(2.08 2.46
2.53-2.98)
(3.24-3.81)
(3.83-4.54
4.73-5.61)
(5.51-6.58)
(6.36-7.64)
7.29-8.81)
(8.69-10.6)
(9.88-12.3)
6-hr
2 59 3.04
3. 4 3869
4.014.73)
4.785863)
(5. 0 B 98)
1(6.89-8.19)
(7.99 9.55)
(9.16-11.1)
3.4)1(12.5
5.6)
3.26
3.96
5.11
6.14
7.69 7
F 9.09
10.7
12.5
(11.0-
15.3
17.7
12-hr
(3.00-3.58
3.644.33)
1 (4.70-5.59)
(5.61-6.69)
1 (6.97-8.37)
1 (8.20-9.87)
9.55-11.6
11.0-13.5)
(13.3-16.6)
,
15.3-192
3 83
4.64
6.07
7.21
9.06
10.7
12.6
14.7
18.0
21.0
24-hr
(3.494.27)
(4.23-5.19
5.47-6.70)
(6.54-8.03)
1 (8.13-10.1)
1(9.53-11.9)
(11.1-14.0)
(12.8-16.4)1(15.3-20.2)
(17.5-23.5)
4.53
5.47
7.0-2
8.36
10.4
12.2
14.2
16.6
20.1
23.1
2-day
4.145.01)
(5.01-6.06)
6.41-7.78)
7.61-9.26)
(9.39-11.5)
(10.9-13.6)
(12.6-15.9
14.4-18.5)
(17.1-22.6
(19.4-26.2
3-day
4.83
(4.42-5.34)
5.83
5.34-6.45
7.42
(6.78-8.22)
8.80
(8.01-9.74)
10.9
9.81-12.1
12.7
(11.3-14.1)
14.7
1(13.0-16.4)
17.0
20A
17.5-23.0)
23.4
19.7-26.5
i
5.13
6.18
7.83
9 24
11.3
13.2
15.2
(14.8-19.0
17.4
20.8
23.7
4�18
(4.70-5.67)
(5.67-6.83)
(7.15-8.65)
(8.41-10.2)
1 (10.2-12.6)
(11.8-14.6)
[(13.5-16.9)
(15.2-19.4)
(17.9-23.3)
(20,1-26.8)
7-da 5.91 7.11 8.94 10.5 12.7 14.6 16.6 18.9 22.1 24.9
(5.46-6.44) 8.26-9.76) (9.64-11.4) 1 (11.6-13.9) (13.3-15.9) (15.0-18.2) (16.8-20.7)1(19.4-24.5)1(21.5-27.7)
� 6.67 7.98 9.89 11.5 13.8 15.7 17.8 20.1 23.4 26.1
10-day (6.18-7.24) 7.40 8.67 9.14-10.8) (10.6-12.5) 1 (12.7-15.0) 14.4-17.2) (16.1-19.5) (18.0-22.0) (20.7-25.8)[(22.B-29.0)
120-day
8.84 10.6 13.0 14.9 17.6 19.9 22.3 24.8 28.4 31.4
(8.33-9.62) (9.93-11.5) (12.1-14.0) 1 (13.8-16.0) 1 (16.3-19.0 (18.3-21.5) (20.3-24.1) 1(22.4-27.0) (25.4-31.1) (27.6-34.6
11.0 13.0 15.6 17.8 20.7 23.1 25.5 28.0 31.5 34.2
30-day
(10.3-11.7) (12.3-13.9) (14.7-16.7) 1 (16.7-18.9) 1 (19.3-22.1) 1(21.4-24.6) (23.6-27.3) (25.7-30.1) 2B.5-34.1) (30.7-37.2)
13.7 16.2 19.2 21.6 25.D , 27.6 30.4 33.2 37.0 40.D
a5-day
12.9-14.6) 1 (15.3-17.2) 18.1-20.4) 20.4-22.9) (23.5-26.5) JI (25.8-29.4) (28.2-32.3) 1(30.6-35.4) (33.7-39.7)1(36.2-43.2
60-day 16.5 19.4 22.7 25.3 28.8 31.5 34.3 37.0 40.6 43.3
(15.6-17.4) 18.3-20.5) (21.4-24.0) (23.8-26.8) 27.1-30.5 (29.5-33.5) (31.9-36.4 3437.3-43.5) (39.6-46.7)
(.3-39.4
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency
estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates
at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Bads to Top
PF graphical
hftps://hdac.nws.noaa.gov/hdsctpfds/pfds_printpage.html?lat=34.2669&Ion=-77.9209&data=depth&units=englisi,&series=pds 1/4

2/12/2020 Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Wilmington, North Carolina, USA*
-� Latitude: 34.26691, Longitude:-77.9209*
Elevation: 24.99 ft**
source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF caphical j dos & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Duration
Average
recurrence interval (years)
1 2
10
25
501
100
200
500
1000
6.25
7.42
8.69
9.70
11.0
11.9
12.9
13.8
15.1
5-mtn
(5.86-6.72)
(6.94-7.97)
(8.12-9.31)
(9.01-10.4)
(10.2-11.7)
1 (11.0-12.7)
(11.8-13.8)
1 (12.6-14.8)
L13.6-16.2)
16.1
(14.4-17.3)
5.00
5.93
6.96
7.75
8.72
9.47
10.2
11.0
11.9
10-mtn
12.7
4.68-5.37)
(5.55-6.37)
(6.50-7.46)
7.21-8.31)
(8.09-9.33)
(8.74-10.1)
(9.38-10.9)
(9.99-11.8)
1 (10.8-12.8)
11.3-13.6)
416
4.97
5.87
6.54
7.37
8.00
8.62
9.22
10.0
15-min
(3.90-4.48)
4.65-5.34
(5.48-6.29)
1 (6.08-7.01)
(6.83-7.88
7.37-8.56)
(7.91-9.22)
(8.40-9.88)
[(9.03-10.8)
10.6
(9.48-11.4)
30-min
2 678507)
3.21 3369)
3. 0-447
4.41 5408)
(5.06 5684)
(5.55-6.45)
6. 5-67006
(6.547 .69)
(7. 8 8656
7.68 9924)
1.78
2.15
2.67
3.08
3.64
4.08
4.55
5.04
5.71
60anin
6.27
(1.67-1.91)
(2.02-2.31)
(2.50-2.87)
2.87-3.31)
3.37-3.89
(3.76-4.37)
(4.17-4.87)
4.59-5.40
(5.15-6.14)
(5.61-6.74
1.05
1.28
1.63
1.93
2.36
2.74
3.15
3.60
F
2-hr
4.27
4.84
(0.972-1.15)
(1.18-1.39)
(1.51 1.78)
(1.78-2.10)
(2.16-2.57)
(2.49-2.98)
(2.85-3.42)
(3.23-3.90)
(3.79-4.63)
(4.27-5.28)
0.750
0.909
1.17
1.39
1.72
2.02
2.35
2.71
3-hr
3.28
3.77
(0.694-0.818)1(0.841-0.992)
(1.08-1.27)
1 (1.28-1.51)
1 (1.58-1.87)
1 (1.83-2.19)
1 (2.12-2.54)
2.43-2.93)
(2.90-3.54)
1 (3.29-4.08
6-hr
0.466
(0.432-0.508)1(0.524
0.565
0.617)1(0.671-0.790)
0.725
0.865
(0.798-0.941)
1.08
0.986-1.17)
1.26
1.15-1.37
1.48
(1.33-1.59)
1.79
1.53-1.85)
Y.08
1.83-2.25)
2.40
0 271
0.329 1
F 0.424
0.509
0.638
0.754
0.885
1.03
1.27
1 (2.09-2.60)
1.47
12-hr
(0.249-0.297)1(0.302-0.359)
(0.390-0.464)
(0.466-0.555)1(0.579-0.695)
0.680-0.819)
(0.793-0.961)1(0.916-1.12)
1 (1.11-1.38)
1.27-1.60
24-hr
0160
0.194
0.250
0.300
0.378
0.446
0.525
0.614
0.751
0.873
(0.145-0.178)1(0.176-0.216)
(0.228-0.279)
(0.273-0.335)
(0_339-0.419)1(0.397-0.495)
(0.461-0.582)
(0.532-0.682)1(0.638-0.840)
(0.729-0.981)
0 2-da
0.094
0.086-0.104)
0.114
(0.104-0.126)
0.146
0.134-0.162)
0.174
0.159-0.193)
0.217
(0.196-0.240)
0.254
(0.228-0.283)
0.297
(0.262-0.331)
0.345
1(0.300-0.386)
0.418
(0.356-0.470)
0.482
1(0.404-0.545)
0 3-day
0.067
0.081
0.103
0.122
0.151
0.176
0.204
0.236
0.2&4
0.325
(0.061-0.074)
0.074-0.090)
(0.094-0.114)
(0.111-0.135)
0.136-0.167
0.158-0_196
(0.181-0.227)
(0.206-0.263
0.243-0.319)
(0.274-0.368
0.053
0.064
0.082
0.096
0.118
0.137
0.158
0.181
0.216
0.247
4-da
(0.049-0.059)
0.035
(0.059-0.071)
0.042
(0.074-0.090
0.053
(0.088-0.106)
0.062
(0.107-0.131)
0.076
(0.123-0.152)
0.087
0.140-0.176)
0.099
(0.159-0.202)
0.112
(0.186-0.243)1(0.209-0.279)
0.132
0.148
7-da
(0.033-0.038)1(0.039-0.046)
(0.049-0.058)
(0.057-0.068)1(0.069-0.083)
(0.079-0.095)
(0.089-0.108)
(0.100-0.123)
(0.116-0.146)
(0.128-0.165
0.028
0.033
0.041
0.048
0.058
0.066
0.074
0.084
0.098
0.109
10-da y
(0.026-0.030)
0.031-0.036
0.038-0.045)
(0.044-0.052)
0.053-0.063)
(0.060-0.071
(0.067-0.081)
(0.075-0.092)
0.086-0.108)
(0.095-0.121)
0.019
0.022
0-27
0.031
0.037
0.041
0.046 7
F-O-.O52
0.059
0.065
20-da y
(0.017-0.020)
1(0.021-0.024)
(0.025-0.029)
(0.029-0.033)
1(0.034-0.040)
(0.038-0.045)
(0.042-0.050)
J(0.047-0.056)
0.053-0.065)
(0.058-0.072
0.015
0.018
0.022
0.025
0.029
0.032
0.035
0.039
0.044
0.047
30-da y
(0.014-0.016)
(0.017-0.019)
1(0.020-0.023)
(0.023-0.026)
(0.027-0.031)
1(0.030-0.034)
(0.033-0.038)
0.036-0.042
0.040-0.047)
(0.043-0.052)
0.013
0.015
0.D18
0.020 7
F 0.023
0.026
0.028
0.031
0.034
-37
45-da y
0.012-0.013)
(0.014-0.016)
(0.017-0.019)
0.019-0.021)
(0.022-0.025)
(0.024-0.027)
(0.026-0.030)
1(0.028-0.033)
(0.031-0.037)
0.033-0.040)
0.011
0.013
0.016
0.018
0.020
0.022
0.024
0.026
0.028
0.030
60-day
(0.011-0.012)
0.013-0.014)
(0.015-0.017)
(0.017-0.019)
0.019-0.021
0.021-0.023)
(0.022-0.025)
( 0.024-0.027
(0.026-0.030)
(0.027-0.032
t Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probabie maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
hftps://hdsc.nws.noaa.gov/hdsclpfds/pfds_printpage.html?lat=34.2669&Ion=-77.9209&data=intensity&units=english&series-pds 1 /4

PIEDMONT
ENVIRONMENTAL
ASS 0 C I ATE S o P A
7/31/2020 Project # 1775
Timmons Group
5410 Trinity Rd., Suite 102
Raleigh, NC 27607
This report details the findings of a seasonally high-water table evaluation for the
Wilmington Airport site in New Hanover County, NC. Your office gave the location of
the proposed storm water control measures (SCM) and requested boring locations. G.
Christopher Murray, Licensed Soil Scientist #1284, conducted the evaluation on July
27th, 2020. The results were as follows:
Seasonally High -Water Table Soil Borings
Soil boring were completed within the proposed stormwater control measure at the
locations shown on the attached map. The depth to the seasonally high-water table
(SHWT) was determined by observing soil indicators, also known as redoximorphic
features.
Boring 1:
Signs of a seasonally high-water table were observed from 8 inches to 120 inches. The
existing grade at this location was 19.5 ft +/-.
Boring 2:
Signs of a seasonally high-water table were observed from 10 inches to 120 inches. The
existing grade at this location was 20.5 ft +/-.
Boring ED
SHWT Depth
inches
SHWT
Elevation feet
1
8-120
18.8 +/-
2
10-120
19.6 +/-
216 S. Swing Rd., Suite 1 Greensboro, NC 27409 336-662-5487

Piedmont Environmental Associates, PA is pleased to perform this work for you. If you
have any questions, please feel free to call [phone].
Sincerely,
G. Christopher Murray
N.C. Licensed Soil Scientist #1284
L

Timmons Group - Wilmington Airport Project (TG 37630.054)
PIEDMONT Job#:1775
E i!+l V i R O N i -i E I I A L 216 S. Swing Rd. Suite 1 Date: 7/31 /20
A s s o z; A- F VO s. a. A. Greensboro, NC 27409 Client: Timmons Group
piedmontsoil.com County: New Hanover
—` W,
SOIL° ty
ow
' OpHe# r
_ Legend
Boring Locations
mod' ""�'■""'� '!" - - r-' �''� -
;�'�
lk
L
w.
inch = 200 feet

a
ML
6.
,f
r
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Tad;
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T.
NOTE:
DRAINAGE AREA MAP BASED ON:
• SURVEY PROVIDED BY PARAMOUNT
ENGINEERING, INC DATED 11/20/19
• NEW HANOVER COUNTY GIS AND
NCONEMAP AERIAL DATED 02/13/2019.
SOIL TYPES:
SYMBOL
RATING
UNIT NAME
JO
D
JOHNSTON SOILS
Le
BID
LEON SAND
Pn
BID
PANTEGO LOAM
Se
AID
SEAGATE FINE SAND
LEGEND
04 HYDRAULIC ANALYSIS POINT
M DRAINAGE AREA LIMITS
TC FLOW PATH
SOIL TYPE BOUNDARIES
<MD
EXISTING IMPERVIOUS
<; fir .,� ; ;
E;� �, ;� ,; �
EXISTING WOODS
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PREVIOUSLY PERMITTED PLAN REVISION
(LOT #9 & ROADWAY) 7/16/15
BASIN INFORMATION
PHASE I & 11
PHASE Ill
RECEIVING STREAM NAME
SMITH CREEK
SMITH CREEK
STREAM CLASS & INDEX NO.
C, Sw 18-74-63.
C, Sw 18-74-63
DRAINAGE AREA (SF)
12,529,107
1,511,968
ON -SITE DRAINAGE AREA (SF)
12,529,107
1,511,968
OFF -SITE DRAINAGE (SF)
0
0
PROPOSED IMPERVIOUS * AREA (SF)
8,520,835
1,230,351
% IMPERVIOUS * AREA (TOTAL)
68.00%
81.40%
IMPERVIOUS* SURFACE AREA
N/A
ON -SITE BUILDINGS (SF)
10,377
N/A
ON -SITE STREETS (SF)
52,520
N/A
ON -SITE PARKING (SF)
51,985
N/A
ON -SITE SIDEWALKS (SF)
14,200
N/A
OTHER ON -SITE (SF)
0
N/A
FUTURE DEVELOPMENT (SF)
3,012,132
899,275
OFF -SITE (SF)
N/A
331,076
EXISTING BUA *** (SF)
5,379,621
N/A
TOTAL (SF)
8,520,835
1,230,351
PLAN REVISION
BASIN INFORMATION
PHASE I & 11
PHASE IIIA
PHASE IIIB
PHASE IIIC
(REMAINING)
RECEIVING STREAM NAME
SMITH CREEK
SMITH CREEK
SMITH CREEK
SMITH CREEK
STREAM CLASS & INDEX NO.
C, Sw 18-74-63
C, Sw 18-74-63
C, Sw 18-74-63
C, Sw 18-74-63
DRAINAGE AREA (SF)
12,529,107
213,213
756,099
542,656
ON -SITE DRAINAGE AREA (SF)
12,529,107
213,213
756,099
542,656
OFF -SITE DRAINAGE (SF)
0
0
0
0
PROPOSED IMPERVIOUS * AREA (SF)
8,520,835
116,598
367,596
299,030
% IMPERVIOUS * AREA (TOTAL)
68.00%
54.70%
48.60%
55.10%
IMPERVIOUS * SURFACE AREA
ON -SITE BUILDINGS (SF)
10,377
5,333
0
N/A
ON -SITE STREETS (SF)
52,520
13,746
103,565
N/A
ON -SITE PARKING (SF)
51,985
44,451
0
N/A
ON -SITE SIDEWALKS (SF)
14,200
4,228
0
N/A
OTHER ON -SITE (SF)
0
52
0
299,030
FUTURE DEVELOPMENT (SF)
3,012,132
48,788
264,031
NIA
OFF -SITE (SF)
N/A
N/A
N/A
N/A
EXISTING BUA *** (SF)
5,379,621
N/A
N/A
N/A
TOTAL (SF)
8,520,835
1 116,598
367,596
299,030
pi
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ALL CONSTRUCTION TO BE IN ACCORDANCE WITH ALL NEW HANOVER COUNTY, CAPE FEAR
PUBLIC UTILITY AUTHORITY, NCDEQ, AND NCDOT STANDARDS, SPECIFICATIONS, AND DETAILS
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FUTURE BUILDOUT IMPERV. (A) = 33,627 SF = 0.77 AC
FUTURE BUILDOUT IMPERV. (B) = 112,570 SF = 2.58 AC
» x FUTURE BUILDOUT LAWN A = 78,438 SF = 1.80 AC
FUTURE BUILDOUT LAWN (B) = 115,225 SF = 2.65 AC
339,860 SF = 7.80 AC
TOTAL
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x 490 LF @ 0 93 /o �� ` µ / d" k„,.. € ' _... _....._ _.... _......_ .._ '.�` ..........k r f
99 _
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� ,, } .. ....._ .._Z'_.... €f .. $ ......._._.../q�f�%i.......... ... �"......_.. .._... w,<,.. <.....w
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•
'
` 3 k,
} .aa,t,`�'4xr� L� \ $. ,,.�'�• 'w., � 3 .. / �` .W,.. .d'. y.,y"••s i / i `*., x*, '^+w � ```` x'`>. ,/ '•e i " n,.,. ....„.
L✓ xwr'. > -YVv r£�3 ,q �` `.,,. 't ``., .,.»,. ,w,,, .,.„<n ..'..' ✓,,,. ,�
� �.n �„ •.� r}f�. A
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'•'� °""' '�` "tom
'� a'k r3 ��`', � k� x ? „,a„r' •i . �,,.. ��'" ra'" ,,--.r; £ "� y,ww yf",., � � yy e 4, ` "*,.n ""• � ... ..,.. �k. 9y�/,g .�' ¢g
/ �./ ^w�a§\ *z `�,k �•� k© _ i!�:.' - 'l ,�,e'" i."ez g',°',.� S i '� Fri / f // L 6" 3 4 jx,,,`� //�^' 3• '`r;` w„» "�» .,✓^' .nd ¢,,, •`�' `'`' 'S x xka's*a\ °ia4ka�b�. `q'eX,4k @:w`��x \'* as �A„"'.iz'.�,/�• `�.,, i ('f� #»"LL..a3k �_ a,,,.,�,„",� w, 88 `"� �,! 'E '^w/'3Zi: �;° � @ i, / y/ ,{ /"�� F?' �,. `` w�.'^„»,``'�"w,�•w/
�j •� N ,,,,, ,;,�' .%.' ""' "''a, `k, `� �`# ,., i�'�.i /� a, / iy"'6�13/
'
�' >• ,y"�;�,'. � . !/y„a"" � / l ..,.,,,".:� ; I $ ^r«i.». 'c, �»w,... `'•• £ w � t ✓iiittc „gay �'r
BUILDOUT TO PROPOSED ;^ BUILDOUT TO EXISTING 4z a p
,Nr
f,
DA 2.1(BYPASts)�k ,> H.
an s 8' /� ar d aj /3
� � £, / �, DA 2.3B (TO PHASE {IIB DRY POND) , 4; j PHASE IIIB DRY POND •� �.� , �`� PHASE I/II DRY POND
TC = 5 MIN�/d
� #���„ � � '€d� rf � �y ,➢' � r, i w" S��S `� �•"�w' ,.,,, +nn "^'v»,,,, "''�w,.»'•^�.�.'" ' �f �' � ... � ,,,.. ✓ ,.,.,
IMPERV. (A) - 29 939 SF = 0.69 AC-
5 DA 2.2 (TO PHASE IIIA DRY POND)
,%E" i
TC = 5 MIN =t 3 TC SEGMENT #3 _:..
IMPERV. (B)- 88 SF - 0.00 AC k , k5.a » » �.„ ....
t DITCH FLOW OA �. .
LAWN (A) - 58,711 SF - 1.35 AC\\�� ,y»0'� 1095 LF @ 0.73% " g
��. 3' \ ` '4 4 r/ .'0 z / °`r»•cy, V' S, h.y '', `. �"""">. a�b< "^.."'Mh `+\ F �j � € �i� � S �S �b ��iaS
LAWN (B) = 105 SF = O.QO ACk 9 f'� 4 ya b� t,n££- ,` s,
r°^w� 'C,,, fi3F �, tl _ `,>.'»'�`a, `*"•„ �rs ,.i' j € £
TOTAL - 88,843 SF 2.04 AC » _
ANALYSIS POINT A i` i _ } e f A� w DA 2.3B (TO PHASE 111B DRY POND �,..a�ry
84' OF 24" RCP a 0.47% SLOPE
# »' „< 3. .,�
INVERT IN:16.92' k � ``\. -V FUTURE BUILDOUT IMPERV. (B) 2217399 SF 5.08 AC = -'
PROPOSED GRASS �� » i
i•,t Z
INVERT OUT:16.52' " » b t �` FUTURE BUILDOUT LAWN(A)9 701 SF - 0.22 AC" PRETREATMENT SWALE , = < �
FUTURE BUILDOUT LAWN (B) - 1827650 SF - 4.20 AC
`` fir, 'i ` .ek'' `�?' "'"'", .,.„.., ,.„,,. .,w.�»..ti .✓' / L M »a _ _
i $ FUTURE BUILDOUT LAWN D 2,489 SF 0.06 AC££
BUILDOUT TO PROPOSED BUILDOUT TO PROPOSED ( ) £;
PHASE IIIA DRY POND PHASE IIIB DRY POND TOTAL - 416,239 SF - 9.56 AC
�a»` PROPOSED GRASS �n t �� t
PRETREATMENT SWALE
,a PROPOSED IIIA ' �1
.., DRY POND » t----#.. .F 55Il.I ti. t ' €� „�W DA 2.3C BYPASS1/ d
F •`i"'yk ''�'.,'-wrr'.
>S�'�°�,k'• Y i i 'i { 't i F as 3 dY R„ .,,
FUTURE BUILDOUT LAWN (B) - 12,586 SF - 0.29 AC `F
s� ,� M Y,.., i �"' a s;, i �, a � `^'. �•
PO _'{_� _ ..... r�� �' „..,. » FUTURE BUILDOUT LAWN (D) 9,692 SF 0.22 AC ANALYSIS POINT B i ROp SOSO Ep PHASE �, ,5�, - _ 4
86° OF 24" RCP 0.46% SLOPE � x _- P µ » `°'} y w TOTAL - 2 78 S F - 0 51
..
Lal-
a L ` a� T 2,2 AC
DF
INVERT IN: 13.97' / g ___} wh 'Nk.» ' w w " b i}X
»»'» � / � � f �` % �, , � 5�2 a � ''42 c ;� tZ � ,�„ ��% ��p� Z;x.. ij€' .,••w"`" �$ ���'""''"'Fi s �4
" INVERT OUT: 13.57 r`Q "`
\� » •`^e. � �'•t' � < � .. Sig �" ! "' �S� T k• �> �� ....t.., ,,,„.`�'rotY ....,.n .^'..... „� w,.'n .w..." .w.,. ,.,, .n,.... „M �n
�AALYSIS POINT C if
el
�=w a , DA 2.4(BYPASS)�E_ � � � � � _�n � �
DA 2.2(PHASE IIIA DRY POND)r _ _ „„ fs /
IMPERV.(A)2 153 SF 0.05 AC { _ :4a,s
IMPERV. (A) = 61,136 SF = 1.40AC / �\ IMPERV. B=3595SF=0.08AC
IMPERV.(B)= 55 462 SF = 1.27 AC, - - -�► IMPERV. (D) - 1,545 SF - 0.04 AC g gg
201q 2x' ' 3 •" � a v e .�. �/ e^� g F { C f
LAWN(A)56 967 SF 1.31 AC - - ;„ s .. a La LAWN (A) = 11,698 SF - 0.27 AC / z
= A s }/ $ rn - -
LAWN (B) - 36,932 SF 0.85 C 4e _ _ _ {
LAWN(B)61,768 SF 1.42 AC _ 3
4a i
LAWN D=2,716SF=0.06AC f k w D=7109SF-0.16AC
( )� x LAWN ( ) 4 _
µ TOTAL - 213,213 SF - 4.89 AC fE - " _ _ \ �i �, €,, PRELIMINARY NOT RELEASED FOR CONSTRUCTION
i �
TC SEGMENT �3 ,m TOTAL = 87,868 SF - 2.02 AC
». DITCH FLOW ,-,L-L. CONSTRUCTION TO BE IN ACCORDANCE WITH ALL NEW HANOVER COUNTY, CAPE FEAR
360 LF @ 2.35% E TC SEGMENT #2 TC SEGMENT #1
SHALLOW CONCENTRATED FLOW SHEET FLOW PUBLIC UTILITY AUTHORITY, NCDEQ, AND NCDOT STANDARDS, SPECIFICATIONS' AND DETAILS
240 LF @ 0.83% 50 LF @ 0.40% ® t f t 7a
NOTE:
1. POST -DEVELOPMENT DRAINAGE AREA
SHOWN IS CONSISTENT WITH
SWB0505047 PHASE III OVERALL
DRAINAGE MAP FOR ULTIMATE BUILDOUT.
2. DRAINAGE AREA MAP BASED ON:
• SURVEY PROVIDED BY PARAMOUNT
ENGINEERING, INC DATED 11/20/19.
• NEW HANOVER COUNTY GIS AND
NCONEMAP AERIAL DATED 02/13/2019.
DA 2.2 (TO PHASE IIIA DRY POND)
PROPOSED IMPERVIOUS WITH CIRCLE K PROJECT
69,896 SF = 1.60 AC (INCLUDES 0.05 AC
IMPERVIOUS CONTINGENCY
TOTAL PHASE IIIA IMPERVIOUS ALLOCATION
= 116,598 SF = 2.67 AC
PHASE IIIA FUTURE DEVELOPMENT IMPERVIOUS
ALLOCATION REMAINING = 46,702 SF = 1.07 AC
DA 2.3 (TO PHASE 111B DRY POND)
EXISTING ROAD IMPERVIOUS = 95,932 SF = 2.20 AC
'PROPOSED IMPERVIOUS WITH CIRCLE K PROJECT
ROAD = 7,633 SF = 0.18 AC
�IEXISTING/PROPOSED ROADS IMPERVIOUS
(SUBTOTAL = 103,565 SF = 2.38 AC
TOTAL PHASE IIIB IMPERVIOUS ALLOCATION =
367,596 SF = 8.43 AC
PHASE IIIB FUTURE DEVELOPMENT IMPERVIOUS
ALLOCATION REMAINING = 264,031 SF = 6.05 AC
■
SOIL. TYPES:
SYMBOL
RATING
UNIT NAME
JO
D
JOHNSTON SOILS
Le
B/D
L ON E SAND
Pn
B/D
PANTEGO LOAM
Se
A/D
ISEAGATE FINE SAND
LEGEND
HYDRAULIC ANALYSIS POINT
M DRAINAGE AREA LIMITS
SOIL TYPE BOUNDARIES
<MD
KNOWN IMPERVIOUS
co
00
a
Z
SCALE 119=100'
0 100' 200'
CARON/
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SEAL
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PEAK FLOW ANALYSIS

Circle K - NTI Airport Blvd Wimington
Stormwater Summary Table
8-Mar-21
Pre-Dev Table of Subareas, Land Uses, & Curve Numbers
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Pre-DA 1.1
50
4.53
Impervious (A)
98
0.68
Impervious (B)
98
0.02
Woods (B)
55
0.01
Lawn (A)
39
3.47
Lawn (B)
61
0.35
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Pre-DA 1.2
50
4.62
Woods (A)
30
0.68
Woods (B)
55
3.20
Woods (D)
70
0.14
Lawn (A)
39
0.47
Lawn (B)
61
0.10
Lawn (D)
74
0.03
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Pre-DA 1.3
61
15.47
Impervious (A)
98
0.35
Impervious (B)
98
1.49
Woods (B)
55
5.71
Woods (D)
70
0.26
Lawn (A)
39
1.74
Lawn (B)
61
5.92
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Pre-DA 1.4
60
1.85
Impervious (B)
98
0.08
Woods (A)
30
0.02
Woods (B)
55
0.06
Lawn (A)
39
0.24
Lawn (B)
61
1.36
Lawn D
74
0.09

Circle K - NTI Airport Blvd Wimington
Stormwater Summary Table
8-Mar-21
Post- Dev Table of Subareas, Land Uses, & Curve Numbers
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.2 (Phase IIIA)
76
4.89
Impervious (A)
98
1.40
PERCENT IMPERV.
54.7°%
Impervious (B)
98
1.27
Lawn (A)
39
1.31
Lawn (B)
61
0.85
Lawn (D)
74
0.06
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.3A (Phase IIIB)
72
7.80
Future Impervious (A)
98
0.77
PERCENT IMPERV.
43.0%
Future Impervious (B)
98
2.58
Future Lawn (A)
39
1.80
Future Lawn (B)
61
2.65
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.313 (Phase IIIB)
80
9.56
Future Impervious (B)
98
5.08
PERCENT IMPERV.
53.2%
Future Lawn (A)
39
0.22
Future Lawn (B)
61
4.19
Future Lawn (D)
74
0.06
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.3C (Phase IIIB)
67
0.51
Future Lawn (B)
61
0.29
PERCENT IMPERV.
0.0°%
Future Lawn (D)
74
0.22
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.1
59
2.04
Impervious (A)
98
0.69
Impervious (B)
98
0.00
Lawn (A)
39
1.35
lawn (B)
61
0.06
Subarea:
Composite CN:
Total Area (ac)
Land Use:
CN:
Area (ac)
Post-DA 2.4
62
2.02
Impervious (A)
98
0.05
Impervious (B)
98
0.08
Impervious (D)
98
0.04
Lawn (A)
39
0.27
Lawn (B)
61
1.42
Lawn(D)
74
0.16

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I
Watershed Model SchematicHydraflowHydrographsExtension for Autodesk® Civil 3D®2019byAutodesk,Inc. v2019.2
1 2 3 4 9 10 11 12 13 14
116"
II
7
Legend
k)II, Origin Description
1 SCS Runoff Pre DA 1.1 (Outlet A)
2 SCS Runoff Pre DA 1.2
3 SCS Runoff Pre DA 1.3 (Outlet C)
4 SCS Runoff Pre DA 1.4
6
Combine
Pre-Dev Outlet B
7
Combine
Pre-Dev TOTAL OUT
9
SCS Runoff
Post DA 2.1 (Outlet A)
10
SCS Runoff
Post DA 2.2
11
SCS Runoff
Post DA 2.3A
12
SCS Runoff
Post DA 2.313
13
SCS Runoff
Post DA 2.3C
14
SCS Runoff
Post DA 2.4
16
Reservoir
DRY POND - WEST
17
Combine
Post Inflow to East Pond
18
Reservoir
DRY POND - EAST
20
Combine
Post-Dev Outlet B (Detained)
21
Combine
Post-Dev Outlet C (Detained)
22
Combine
Post Out Total (Detained)
20
22
21
Project: 37630.054 - Hydraflow - 2021.03.04.gpw I Sunday, 03 / 7 / 2021

Hydrograph Return Period RFTyd-raWydrographsExtension for Autodesk® Civil 3D®2019byAutodesk,Inc. v2019.2
Hyd.
No.
Hydrograph
type
Inflow
hyd(s)
Peak Outflow (cfs)
Hydrograph
Description
(origin)
1-yr
2-yr
3-yr
T-Yr
10-yr
25-yr
50-yr
100-yr
1
SCS Runoff
----
0.455
1.271
-------
3.427
5.875
10.28
14.66
20.07
Pre DA 1.1 (Outlet A)
2
SCS Runoff
----
0.490
1.564
------
4.704
8.264
14.57
20.75
28.40
Pre DA 1.2
3
SCS Runoff
------
8.685
15.50
----
28.97
42.08
63.97
84.64
109.34
Pre DA 1.3 (Outlet C)
4
SCS Runoff
------
0.938
1.720
------
3.293
4.834
7.407
9.856
12.79
Pre DA 1.4
6
Combine
2, 4,
1.377
3.170
------
7.674
12.43
20.67
28.88
39.04
Pre-Dev Outlet B
7
Combine
1, 3, 6
10.17
19.26
----
38.43
57.88
91.16
122.66
160.65
Pre-Dev TOTAL OUT
9
SCS Runoff
•-
0.798
1.482
-------
2.891
4.308
6.685
8.920
11.60
Post DA 2.1 (Outlet A)
10
SCS Runoff
8.846
12.45
-----
18.86
24.64
33.68
41.72
51.02
Post DA 2.2
11
SCS Runoff
------
9.816
14.37
----
22.76
30.53
42.87
53.97
66.91
Post DA 2.3A
12
SCS Runoff
----
30.64
41.40
------
60.07
76.61
102.15
124.71
150.72
Post DA 2.3B
13
SCS Runoff
------
0.892
1.350
-------
2.196
2.987
4.293
5.480
6.871
Post DA 2.3C
14
SCS Runoff
-----
1.245
2.170
-----
3.970
5.712
8.615
11.34
14.58
Post DA 2.4
16
Reservoir
10
0.199
0.872
-----
4.031
6.352
9.034
15.16
25.57
DRY POND - WEST
17
Combine
11, 12,
34.29
46.85
-------
68.89
88.65
119.75
147.41
179.43
Post Inflow to East Pond
18
Reservoir
17
1.352
4.553
------
17.14
30.75
46.57
64.45
99.84
DRY POND - EAST
20
Combine
14, 16,
1.334
2.266
-----
6.225
11.02
16.97
24.39
39.90
Post-Dev Outlet B (Detained)
21
Combine
13, 18,
1.378
4.640
------
17.37
31:10
47.12
65.16
101.69
Post-Dev Outlet C (Detained)
22
Combine
9, 20, 21
2.553
5.781
----
26.06
45.98
70.29
98.41
144.99
Post Out Total (Detained)
Proj. file: 37630.054 - Hydraflow - 2021.03.04.gpw
Sunday, 03 / 7 / 2021

Hydrograph Summary Repo rlydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(efs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(tuft)
Hydrograph
Description
1
SCS Runoff
0.455
2
750
4,650
---
------
Pre DA 1.1 (Outlet A)
2
SCS Runoff
0.490
2
73.8
4,446
---
------
Pre DA 1.2
3
SCS Runoff
8.685
2
732
42,141
---
------
Pre DA 1.3 (Outlet C)
4
SCS Runoff
0.938
2
732
4,711
-----
......
Pre DA 1.4
6
Combine
1.377
2
734
9,157
2, 4,
----
Pre-Dev Outlet B
7
Combine
10.17
2
732
55,948
------
Pre-Dev TOTAL OUT
9
SCS Runoff
0.798
2
740
4,696
------
------
Post DA 2.1 (Outlet A)
10
SCS Runoff
8.846
2
724
26,783
—
---
Post DA 2.2
11
SCS Runoff
9.816
2
730
39,189
-----
-----
---
Post DA 2.3A
12
SCS Runoff
30.64
2
716
61,881
----
----
---
Post DA2.3B
13
SCS Runoff
0.892
2
718
1,808
----
----
-----
Post DA 2.3C
14
SCS Runoff
1.245
2
732
5,872
-----
---
-----
Post DA 2.4
16
Reservoir
0.199
2
1110
26,781
10
17.72
20,631
DRY POND - WEST
17
Combine
34.29
2
718
101,070
11, 12,
-----
-----
Past Inflow to East Pond
18
Reservoir
1.352
936
101,065
17
16.60
66,934
DRY POND - EAST
20
Combine
1.334
732
32,653
14, 16,
------
Post-Dev Outlet B (Detained)
21
Combine
1.378
2
934
102,873
13, 18,
—
Post-Dev Outlet C (Detained)
22
Combine
2.553
734
140,222
9, 20, 21
— -
Post Out Total (Detained)
i
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 1 Year
Sunday, 03 / 7 / 2021

Hydrograph Report 4
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
= 0.455 cfs
Storm frequency
= 1 yrs
Time to peak
= 750 min
Time interval
= 2 min
Hyd. volume
= 4,650 tuft
Drainage area
= 4.530 ac
Curve number
= 50*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 17.50 min
Total precip.
= 3.83 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) _ [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
Pre DA 1.1 (Outlet A)
Q (cfs) Hyd. No. 1 -- 1 Year Q (ems)
0.50 0.50
0.45 0.45
0.40 0.40
0.35 0.35
0.30 0.30
0.25 0.25
0.20 0.20
0.15 0.15
0.10 0.10
0.05
0.05
0.00 - I I I 1 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

TR55 Tc Worksheet
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Description
Sheet Flow
Manning's n-value
Flow length (ft)
Two-year 24-hr precip. (in)
Land slope (%)
Travel Time (min)
Shallow Concentrated Flow
Flow length (ft)
Watercourse slope (%)
Surface description
Average velocity (ft/s)
Travel Time (min)
Channel Flow
X sectional flow area (sqft)
Wetted perimeter (ft)
Channel slope (%)
Manning's n-value
Velocity (ft/s)
5
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
A
= 0.150
= 50.0
= 4.64
= 0.80
= 6.74
= 33.00
= 2.27
= Unpaved
=2.43
= 0.23
= 0.83
= 6.80
= 0.93
= 0.026
=1.35
B
0.011
0.0
0.00
0.00
+ 0.00
0.00
0.00
Paved
0.00
+ 0.00
0.00
0.00
0.00
0.015
[�111111f,
C
0.011
0.0
0.00
0.00
+ 0.00
0.00
0.00
Paved
0.00
+ 0.00
0.00
0.00
0.00
0.015
0.00
Flow length (ft) ({0})852.0 0.0 0.0
Travel Time (min) = 10.52 + 0.00 + 0.00
TotalTravel Time, Tc..............................................................................
Totals
6.74
= 0.23
10.52
17.50 m i n

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
6
Sunday, 03 / 7 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 0.490 cfs
Storm frequency
= 1 yrs
Time to peak
= 738 min
Time interval
= 2 min
Hyd. volume
= 4,446 cuft
Drainage area
= 4.620 ac
Curve number
= 50*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 6.40 min
Total precip.
= 3.83 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74)] 14.620
Pre DA 1.2
Q (cfs) Qcfs
Hyd. No. 2 -- 1 Year ( )
0.50
0.50
0.45
0.45
0.40
0.40
0.35
0.35
0.30
0.30
0.25
0.25
0.20
0.20
0.15
0.15
0.10
0.10
0.05 I -
0.05
0.00 -1 1 ' I — I- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2
Time (min)

TR55 Tc Worksheet
Hyd. No. 2
Pre DA 1.2
Description
Sheet Flow
Manning's n-value
Flow length (ft)
Two-year 24-hr precip. (in)
Land slope (%)
Travel Time (min)
Shallow Concentrated Flow
Flow length (ft)
Watercourse slope (%)
Surface description
Average velocity (ft/s)
Travel Time (min)
Channel Flow
X sectional flow area (sqft)
Wetted perimeter (ft)
Channel slope (%)
Manning's n-value
Velocity (ft/s)
7
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
A
= 0.150
= 50.0
= 4.64
= 1.28
= 5.59
= 76.00
= 1.89
= Unpaved
=2.22
= 0.57
= 13.56
= 1.00
= 1.94
= 0.026
=45.79
B
0.011
0.0
0.00
0.00
+ 0.00
0.00
0.00
Paved
0.00
+ 0.00
0.00
0.00
0.00
0.015
0.011
0.0
0.00
0.00
+ 0.00
0.00
0.00
Paved
0.00
+ 0.00
0.00
0.00
0.00
0.015
0.00
Flow length (ft) ({0))567.0 0.0 0.0
Travel Time (min) = 0.21 + 0.00 + 0.00
TotalTravel Time, Tc..............................................................................
Totals
5.59
0.57
0.21
6.40 min

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.470 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 3.83 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) _ [(1.840 x 98) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 61)] / 15.470
MIX
M
4.00
2.00
8
Sunday, 0317 / 2021
= 8.685 cfs
= 732 min
= 42,141 cuft
= 61*
= 0 ft
= 12.90 min
= Type III
= 484
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 1 Year
Q (cis)
10.00
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
F]yd No. 3
Time (min)

TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Description
A
B
C
Totals
Sheet Flow
Manning's n-value
= 0.150
0.011
0.011
Flow length (ft)
= 50.0
0.0
0.0
Two-year 24-hr precip. (in)
= 4.64
0.00
0.00
Land slope (%)
= 0.50
0.00
0.00
Travel Time (min)
= 8.14 +
0.00 +
0.00 =
8.14
Shallow Concentrated Flow
Flow length (ft)
= 0.00
0.00
0.00
Watercourse slope (%)
= 0.00
0.00
0.00
Surface description
= Paved
Paved
Paved
Average velocity (ft/s)
=0.00
0.00
0.00
Travel Time (min)
= 0.00 +
0.00 +
0.00 =
0.00
Channel Flow
X sectional flow area (sqft)
= 1.50
12.44
0.00
Wetted perimeter (ft)
= 2.40
4.00
0.00
Channel slope (%)
= 0.90
0.51
0.00
Manning's n-value
= 0.026
0.026
0.015
Velocity (ft/s)
=3.97
8.75
0.00
Flow length (ft)
Q0))708.0
920.0
0.0
Travel Time (min)
= 2.97 +
1.75 +
0.00 =
4.73
TotalTravel Time, Tc..............................................................................
12.90 min

Hydrograph Report
10
Hydraflow Hydrographs Extension for Autodesk® Civil 3106 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. IN 0. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
= 0.938 cfs
Storm frequency
= 1 yrs
Time to peak
= 732 min
Time interval
= 2 min
Hyd. volume
= 4,711 cuft
Drainage area
= 1.850 ac
Curve number
= 60*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 12.30 min
Total precip.
= 3.83 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Pre DA 1.4
Q cfs
Hyd. No. 4 -- 1 Year Q ( cfs)
1.00 1.00
0.90 0.90
0.80 0.80
0.70 0.70
0.60 0.60
0.50 0.50
0.40 0.40
0.30 0.30
0.20 0.20
0.10
0.10
i
0.00 _L I I I I 1_ �. f I I �- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4
Time (min)

TR55 Tc Worksheet
Hyd. No. 4
Pre DA 1.4
11
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Description
A
B
C
Totals
Sheet Flow
Manning's n-value
= 0.150
0.011
0.011
Flow length (ft)
= 50.0
0.0
0.0
Two-year 24-hr precip. (in)
= 4.64
0.00
0.00
Land slope (%)
= 0.40
0.00
0.00
Travel Time (min)
= 8.90 +
0.00 +
0.00 =
8.90
Shallow Concentrated Flow
Flow length (ft)
= 240.00
0.00
0.00
Watercourse slope (%)
= 0.83
0.00
0.00
Surface description
= Unpaved
Paved
Paved
Average velocity (ft/s)
=1.47
0.00
0.00
Travel Time (min)
= 2.72 +
0.00 +
0.00 =
2.72
Channel Flow
X sectional flow area (sqft)
= 12.60
0.00
0.00
Wetted perimeter (ft)
= 12.00
0.00
0.00
Channel slope (%)
= 2.36
0.00
0.00
Manning's n-value
= 0.026
0.015
0.015
Velocity (ft/s)
=9.10
0.00
0.00
Flow length (ft)
({0})360.0
0.0
0.0
Travel Time (min)
= 0.66 +
0.00 +
0.00 =
0.66
Total Travel Time, Tc..............................................................................
12.30 min

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 6
Pre-Dev Outlet B
12
Sunday, 0317 / 2021
Hydrograph type
= Combine
Peak discharge
= 1.377 cfs
Storm frequency
= 1 yrs
Time to peak
= 734 min
Time interval
= 2 min
Hyd. volume
= 9,157 cuft
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
m
M
Pre-Dev Outlet B
Hyd. No. 6 -- 1 Year
Q (cfs)
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 6 Hyd No. 2 - Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 7
Pre-Dev TOTAL OUT
13
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 10.17 cfs
Storm frequency
= 1 yrs
Time to peak
= 732 min
Time interval
= 2 min
Hyd. volume
= 55,948 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
10.00
M
6.00
4.00
2.00
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 1 Year
Q (cfs)
12.00
10.00
IM
4.00
2.00
0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 Hyd No. 3 Hyd No. 6

Hydrograph Report 14
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
= 0.798 cfs
Storm frequency
= 1 yrs
Time to peak
= 740 min
Time interval
= 2 min
Hyd. volume
= 4,696 cuft
Drainage area
= 2.040 ac
Curve number
= 59*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 16.70 min
Total precip.
= 3.83 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) _ [(0.690 x 98) + (1.350 x 39)] / 2.040
Q (cfs
1.00 1.00
0.90 0.90
0.80 0.80
0.70 0.70
0.60 0.60
0.50 0.50
0.40 0.40
0.30 0.30
0.20 0.20
0.10
0.10
0.00 -� I I I �_ - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 9
Time (min)
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 1 Year

TR55 Tc Worksheet
Hyd. No. 9
Post DA 2.1 (Outlet A)
15
Hydraflow Hydrographs Extension for Autodesk® Civil 308 2019 by Autodesk, Inc. v2019.2
Descriotion
A
B
C
Totals
Sheet Flow
Manning's n-value
= 0.150
0.011
0.011
Flow length (ft)
= 50.0
0.0
0.0
Two-year 24-hr precip. (in)
= 4.64
0.00
0.00
Land slope (%)
= 0.26
0.00
0.00
Travel Time (min)
= 10.57 +
0.00 +
0.00 =
10.57
Shallow Concentrated Flow
Flow length (ft)
= 24.00
0.00
0.00
Watercourse slope (%)
= 3.90
0.00
0.00
Surface description
= Unpaved
Paved
Paved
Average velocity (ft/s)
=3.19
0.00
0.00
Travel Time (min)
= 0.13 +
0.00 +
0.00 =
0.13
Channel Flow
X sectional flow area (sqft)
= 0.83
0.00
0.00
Wetted perimeter (ft)
= 6.80
0.00
0.00
Channel slope (%)
= 0.93
0.00
0.00
Manning's n-value
= 0.026
0.015
0.015
Velocity (ft/s)
=1.35
0.00
0.00
Flow length (ft)
Q0))490.0
0.0
0.0
Travel Time (min)
= 6.05 +
0.00 +
0.00 =
6.05
TotalTravel Time, Tc..............................................................................
16.70 min

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.890 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.83 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
Q (cfs)
10.00
8.00
6.00
4.00
2.00
Post DA 2.2
Hyd. No. 10 -- 1 Year
16
Sunday, 03 / 7 / 2021
= 8.846 cfs
= 724 min
= 26,783 cuft
= 76*
= Oft
= 5.00 min
= Type III
= 484
Q (cfs)
10.00
IM
6.00
i M
Ml
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 10 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.800 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.83 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] / 7.800
Q (Cfs)
10.00
'A111:
6.00
4.00
2.00
Post DA 2.3A
Hyd. No. 11 -- 1 Year
17
Sunday, 03 / 7 / 2021
= 9.816 cfs
= 730 min
= 39,189 cuft
= 72*
= 0 ft
= 12.90 min
= Type III
= 484
Q (cfs)
10.00
MIX
M
4.00
2,00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 12
Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 9.560 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 3.83 in
Distribution
Storm duration
= 24 hrs
Shape factor
30.00
25.00
20.00
15.00
10.00
5.00
18
Sunday, 03 17 / 2021
= 30.64 cfs
= 716 min
= 61,881 cuft
= 80
= Oft
= 5.00 min
= Type II
= 484
Post DA 2.3113
Hyd. No. 12 -- 1 Year
Q (cfs)
35.00
30.00
25.00
20.00
15.00
5.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 12
Time (min)

Hydrograph Report 19
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
= 0.892 cfs
Storm frequency
= 1 yrs
Time to peak
= 718 min
Time interval
= 2 min
Hyd. volume
= 1,808 cuft
Drainage area
= 0.510 ac
Curve number
= 67
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.83 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post DA 2.3C
Q (cfs) Hyd. No. 13 -- 1 Year Q (cfs)
1.00 1.00
0.90 0.90
0.80 0.80
0.70 0.70
0.60 0.60
0.50 0.50
0.40 0.40
0.30 0.30
0.20 0.20
0.10 0.10
0.00 -I I I i I I L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 13 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.020 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 3.83 in
Distribution
Storm duration
= 24 hrs
Shape factor
*Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
Q (cfs)
Post DA 2.4
Hyd. No. 14 -- 1 Year
20
Sunday, 03 / 7 12021
= 1.245 cfs
= 732 min
= 5,872 cuft
= 62*
= 0 ft
= 12.30 min
= Type III
= 484
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14 Time (min)

TR55 Tc Worksheet
Hyd. No. 14
Post DA 2.4
21
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Description
A
B
C
Totals
Sheet Flow
Manning's n-value
= 0.150
0.011
0.011
Flow length (ft)
= 50.0
0.0
0.0
Two-year 24-hr precip. (in)
= 4.64
0.00
0.00
Land slope (%)
= 0.40
0.00
0.00
Travel Time (min)
= 8.90 +
0.00 +
0.00 =
8.90
Shallow Concentrated Flow
Flow length (ft)
= 240.00
0.00
0.00
Watercourse slope (%)
= 0.83
0.00
0.00
Surface description
= Unpaved
Paved
Paved
Average velocity (ft/s)
=1.47
0.00
0.00
Travel Time (min)
= 2.72 +
0.00 +
0.00
2.72
Channel Flow
X sectional flow area (sqft)
= 12.60
0.00
0.00
Wetted perimeter (ft)
= 12.00
0.00
0.00
Channel slope (%)
= 2.36
0.00
0.00
Manning's n-value
= 0.026
0.015
0.015
Velocity (ft/s)
=9.10
0.00
0.00
Flow length (ft)
((0))360.0
0.0
0.0
Travel Time (min)
= 0.66 +
0.00 +
0.00 =
0.66
TotalTravel Time, Tc..............................................................................
12.30 min

Hydrocgraph Report
Hydrafkrw Hydnxraphs Extension for Autodesk@ Civil 3E* 2019 by Autodesk. Inc. v2019.2
Hyd. No. 16
` DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 1 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 10 - Post DA 2.2
Max. Elevation
Reservoir name
= Dry Pond -WEST
Max. Storage
Storage Indication meffwd used.
8.00
6.00
4.00
2.00
0.00
0 600
Hyd No. 16
DRY POND - WEST
Hyd. No. 16 —1 Year
22
Sunday. 031712021
= 0.199 cfs
= 1110 min
= 26,781 cult
= 17.72 ft
= 20,631 tuft
Q (cfs)
10.00
t
6.00
f�1,
2.00
0.00
1200 1800 2400 3000 3600 4200 4800 5400 6000
Hyd No. 10 Total storage used = 20,631 cuf# Time (min)

Pond
Report
23
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 03 17 / 2021
Pond No. 1 - Dry Pond - WEST
Pond Data
Contours -User-defined contour areas. Average end area method used
for volume calculation. Begining Elevation =
14.50 ft
Stage i Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (tuft)
Total storage (tuft)
0.00
14.50
00
0
0
0.50
15.00
238
60
60
1.50
16.00
4,173
2,206
2,265
2.50
17.00
12,673
8,423
10,688
3.50
18.00
15,040
13,857
24,545
4.50
19.00
17,922
16,481
41,026
5.50
20.00
20,792
19,357
50,383
6.25
20.75
23,021
16,430
76,812
l Culvert 1 Orifice Structures
Weir Structures
[A]
[B] [C] [PrfRsr]
[A] [Bl
[C]
[D]
Rise (in)
15.00
1.50 4.00 0.00
Crest Len (ft)
Inactive 15.00
Inactive 0.00
Span (in)
= 15.00
1.50 30.00 0.00
Crest El. (ft)
= 18.75 19.25
0.00
0.00
No. Barrels
1
1 2 0
Weir Coeff.
= 3.33 2.60
3.33
3.33
Invert El. (ft)
14.35
14.50 17.70 0.00
Weir Type
1 Broad
Rect
---
Length (ft)
60.00
5.00 5.00 0.00
Multi -Stage
= Yes No
No
No
Slope (%)
0.25
1.00 1.00 n/a
N-Value
.013
.013 .013 n/a
Orifice Coeff.
0.60
0.60 0.60 0.60
Exfll.(in/hr)
= 0.000 (by Contour)
Multistage
= n/a
Yes Yes No
TW Elev. (ft)
= 0.00
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (a).
Stage ! Storage / Discharge
Table
Stage Storage Elevation
Clv A Clv B
Clv C
PrfRsr Wr A
Wr B Wr C
Wr D
Exfll User Total
ft tuft ft
cfs cfs
cfs
cfs cfs
cfs cfs
cfs
cfs cfs cfs
0.00
0 14.50
0.00 0.UU
0.00
--- 0.00
0.00
--- --- 0.000
0.05
6 14.55
0.10 oc 0.001C
0.00
--- 0.00
0.00
--- 0.004
0.10
12 14.60
0.10 oc 0.01 is
0.00
0.00
0.00
---
--- 0.011
0.15
18 14.65
0.10 oc 0.02 is
0.00
0.00
0.00
---
--- 0.017
0.20
24 14.70
0.10 oc 0.02 is
0.00
0.00
0.00 ---
--
--- --- 0.022
0.25
30 14.75
0.10 oc 0.03 is
0.00
0.00
0.00
--
-- n roc
0.30
36 14.80
0.10 oc 0.03 is
0.00-
0.00
0.00 ---
--
- 0.029
0.35
42 14.85
0.10 OC 0.03 is
0.00
0.00
0.00 ---
--
- 0.032
0.40
48 14.90
0.10 oc 0.03 is
0.00
0.00
0.00 --
--
--- 0.034
0.45
54 14.95
0.10 oc 0.04 is
0.00
--- 0.00
0.00 --
---
--- 0.037
0.50
60 15.00
0.10 OC 0.04 is
0.00
-- 0.00
0.00 --
---
--- 0.039
0.60
280 15.10
0.10 OC 0.04 is
0.00
--- 0.00
0.00 -
--
- --- 0.043
0.70
501 15.20
0.10 oc 0.05 is
0.00
--- 0.00
0.00 --
--
-- 0.047
0.80
721 15.30
0.10 oc 0.05 is
0.00
--- 0.00
0.00 ---
--
--- --- 0.051
I 0.90
942 15.40
0.10 oc 0.05 is
0.00
0.00
0.00
--
- -- 0.054
1.00
1,162 15.50
0.10 oc 0.06 is
0.00
0.00
0.00 ---
-
--- 0.057
1.10
1,383 15.60
0.10 OC 0.06 is
0.00
0.00
0.00 -
-
-- 0.060
1.20
1,603 15.70
0.10 oc 0.06 is
0.00
-- 0.00
0.00 ---
-
--- --- 0.063
I 1.30
1,824 15.80
0.10 oc 0.07 is
0.00
- 0.00
0.00 ---
-
--- --- 0.066
1.40
2,044 15.90
0.10 oc 0.07 is
0.00
0.00
0.00 ---
---
-- 0.068
1.50
2,265 16.00
0.10 oc 0.07 is
0.00
0.00
0.00
-
--- --- 0.071
1.60
3,107 16.10
0.10 oc 0.07 is
0.00
0.00
0.00 --
---
--- --- 0.073
1.70
3,950 16.20
0.10 oc 0.08 is
0.00
-- 0.00
0.00 ---
---
--- --- 0.076
1.80
4,792 16.30
0.10 OC 0.08 is
0.00
-- 0.00
0.00 ---
- -
-- --- 0.078
1.90
5,634 16.40
0.10 OC 0.08 is
0.00
0.00
0.00
---
-- --- 0.080
2.00
6,476 16.50
0.10 oc 0.08 is
0.00
--- 0.00
0.00 ---
---
--- 0.082
2.10
7,319 i6.60
0.10 oc U.08 is
U.UU
--- 0.00
0.00
0.084
l 2.20
8,161 16.70
0.10 oc 0.09 is
0.00
--- 0.00
0.00 --
0.086
2.30
9,003 16.80
0.10 oc 0.09 is
0.00
--- 0.00
0.00 ---
--
--- 0.088
2.40
9,846 16.90
0.10 oc 0.09 is
0.00
--- 0.00
0.00 ---
--
- 0.090
2.50
10,688 17.00
0.10 oc 0.09 is
0.00
--- 0.00
0.00 ---
--
--- 0.092
2.60
12,074 17.10
0.10 oc 0.09 is
0.00
--- 0.00
0.00 ---
-
--- ... 0.094
2.70
13,459 17.20
0.10 OC 0.10 is
0.00
0.00
0.00
-
--- 0.096
2.80
14,845 17.30
0.11 oc 0.10 is
0.00
0.00
___
0.00
--- 0.098
2.90
16,231 17.40
0.11 OC 0.10 is
0.00
0.00
0.00 ---
---
- --- 0.100
LContinues
on next page...

24
Dry Pond
-WEST
Stage /
Storage / Discharge Table
Stage
Storage
Elevation
Clv A
Clv B
Clv C
PrfRsr
Wr A
Wr B
Wr C Wr D Exfil User
Total
ft
cuft
ft
cis
cfs
efs
cfs
cfs
cfs
cis cfs cfs cfs
cis
3.00
17,616
17.50
0.11 oc
0.10 is
0.00
--
0.00
0.00
-- --- --- --
0.101
3.10
19,002
17.60
0.11 oc
0.10 is
0.00
--
0.00
0.00
-- --- --- --
0.103
3.20
20,388
17.70
0.11 cc
0.10 is
0.00 is
---
0.00
0.00
-- --- --- --
0.105
3.30
21,773
17.80
0.65 oc
0.10 is
0.54 is
0.00
0.00
--- -- ---
0.641
3.40
23,159
17.90
1.63 oc
0.10 is
1.52 is
---
0.00
0.00
--- -- ---
1.620
3.50
24,545
18.00
2.89 oc
0.09 is
2.80 is
---
0.00
0.00
--- --- - ---
2.887
3.60
26,193
18.10
3.96 oc
0.09 is
3.88 is
---
0.00
0.00
--- --- -- --
3.964
3.70
27,841
18.20
4.72 oc
0.09 is
4.63 is
--
0.00
0.00
--- --- --
4.719
3.80
29,489
18.30
5.37 oc
0.08 is
5.28 is
0.00
0.00
--- --- -- ---
5.366
3.90
31,137
18.40
5.94 oc
0.08 is
5.86 is
--
0.00
0.00
-- --- --- ---
5.942
4.00
32,785
18.50
6.47 oc
0.08 is
6.39 is
--
0.00
0.00
-- -- --
6.466
4.10
34,433
18.60
6.95 oc
0.08 is
6.87 is
0.00
0.00
--- ---
6.950
4.20
36,081
18.70
7.40 oc
0.08 is
7.33 is
---
0.00
0.00
-- --- --- ---
7.401
4.30
37,729
18.80
7.83 oc
0.07 is
7.75 is
0.00
0.00
--- --
7.826
4.40
39,377
18.90
8.23 oc
0.07 is
8.16 is
---
0.00
0.00
R 99R
4.50
41,026
19.00
8.61 oc
0.07 is
8.54 is
---
0.00
0.00
--- --- ---
8.612
4.60
42,961
19.10
8.98 oc
0.07 is
8.91 is
---
0.00
0.00
--- ---
8.978
4.70
44,897
19.20
9.13 oc
0.07 is
9.06 is
0.00
0.00
-- --
9.126
4.80
46,833
19.30
9.25 oc
0.07 is
9.18 is
---
0.00
0.44
--- ---
9.683
4.90
48,768
19.40
9.37 oc
0.07 is
9.30 is
--
0.00
2.27
--- --- --
11.63
5.00
50,704
19.50
9.48 oc
0.07 is
9.42 is
--
0.00
4.88
--- -- --- ---
14.36
5.10
52,640
19.60
9.60 oc
0.07 is
9.53 is
---
0.00
8.08
-- -
17.58
5.20
54,575
19.70
9.72 oc
0.07 is
9.64 is
0.00
11.77
--- -- - ---
21.49
5.30
56,511
19.80
9.83 oc
0.07 is
9.76 is
---
0.00
15.91
- --- ---
25.74
5.40
58,447
19.90
9.94 oc
0.07 is
9.87 is
---
0.00
20.44
--- -- ---
30.38
5.50
60,383
20.00
10.05 oc
0.07 is
9.98 is
0.00
25.33
--- ---
35.38
5.57
62,025
20.08
10.14 oc
0.07 is
10.06 is
0.00
29.22
--- --- -- ---
39.36
5.65
63,668
20.15
10.22 oc
0.07 is
10.14 is
0.00
33.30
--- ---
43,52
5.72
65,311
20.23
10.30 oc
0.08 is
10.22 is
0.00
37.55
- --- ---
47.85
5.80
66,954
20.30
10.38 oc
0.08 is
10.30 is
--
0.00
41.96
--- -- ---
52.34
5.87
68,597
20.38
10.46 oc
0.08 is
10.38 is
---
0.00
46.54
-
57.00
5.95
70,240
20.45
10.54 oc
0.08 is
10.46 is
---
0.00
51.27
- --
61.81
6.02
71,883
20.53
10.62 oc
0.08 is
10.54 is
---
0.00
56.15
--- -- ---
66.76
6.10
73,526
20.60
10.70 oc
0.08 is
10.62 is
---
0.00
61.17
--- -- __
71.87
6.17
75,169
20.68
10.77 oc
0.08 is
10.69 is
---
0.00
66.34
_--
77.12
6.25
76,812
20.75
10.85 oc
0.08 is
10.77 is
---
0.00
71.65
- -- ---
82.50
...End

Hydrograph
Report
25
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 12021
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
= 34.29 cfs
Storm frequency
= 1 yrs
Time to peak
= 718 min
Time interval
= 2 min
Hyd. volume
= 101,070 cuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
Q (cfs)
35.00
30.00
25.00
i
20.00
I
15.00
10.00
5.00
Post Inflow to East Pond
Hyd. No. 17 -- 1 Year
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 17 Hyd No. 11 - - Hyd No. 12 Time (min)

Hydrograph Report
26
Hydra OW Hydr0gr8yhs Extension for Autode" Civil 3138 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 18
DRY POND - EAST
Hydrograph type
= Reservoir
Peak discharge
= 1.352 cfs
Storm frequency
= 1 yrs
Time to peak
= 936 min
Time interval
= 2 min
Hyd. volume
= 101,065 cult
Inflow hyd. No.
= 17 - Post Inflow to East Pond
Max. Elevation
= 16.60 fi
Reservoir name
= Dry Pond -EAST
Max. Storage
= 66,934 cuft
Storage indication method used.
DRY POND - EAST
Q (S) Q (cis)
Hyd. No. 18 —1 Year
36.00
35.E
i
30.00 30.00
Y
1 j ,
25.00
25.00
1
20.00 20.00
15.00 15.00
L
10.00 o.0a
S.Oti 5.00
j
0.00
0 480 960 1440 1920 2400 2880 3360 3840 4320 4800
Time (min)
—Hyd No. 18 —Hyd No. 17 Total storage used = 66,934 cuff

Pond
Report
27
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Pond No. 2 - Dry Pond - EAST
Pond Data
Contours -User-defined contour areas. Average end area method used
for volume calculation. Beginina Elevation =
13.25 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cult)
Total storage (cult)
0.00
13.25
00
0
0
0.75
14.00
1,529
573
573
1.75
15.00
18,850
10,190
10,763
2.75
16.00
40,779
29,815
40,577
3.75
17.00
47,595
44,187
84,764
4.75
18.00
53,426
50,511
135,275
5.75
19.00
59,262
56,344
191,610
6.75
20.00
65,401
62,332
253,950
Culvert ! Orifice Structures
Weir Structures
[A]
[B] [C] [PrfRsr]
[A] [B]
[C]
[D]
Rise (in)
= 36.00
3.00 12.00 0.00
Crest Len (ft)
= 20.00 50.00
Inactive
0.00
Span (in)
= 36.00
3.00 36.00 0.00
Crest El. (ft)
= 18.00 18.50
0.00
0.00
No. Barrels
1
1 3 0
Weir Coeff.
= 3.33 2.60
3.33
3.33
Invert El. (ft)
13.05
13.25 16.50 0.00
Weir Type
= 1 Broad
Rect
Length (ft)
30.00
5.00 5.00 0.00
Multi -Stage
= Yes No
No
No
Slope (%)
0.50
1.00 1.00 n/a
N-Value
.013
.013 .013 n/a
Orifice Coeff.
0.60
0.60 0.60 0.60
Exfil.(in/hr)
= 0.00n thv r:nntnrrrl
Multi -Stage
- n/a
Yes Yes No
TW Elev. (ft)
= 0.00
Note: Culvert/Orifice outflows are
analyzed under inlet (ic) and outlet (uu) curdrul. Weir risers checked for orifice conditions (ic) and submergence (a).
Stage / Storage / Discharge
Table
Stage Storage Elevation
Civ A Clv B
Clv C
PrFRsr Wr A
Wr B Wr C
Wr D
Exfil User Total
ft cuft ft
cfs cfs
cfs
cfs cfs
cfs cis
cfs
cfs cfs cfs
i0.00
0 13.25
0.00 0.00
0.00
0.00
0.00
--- --- 0.000
0.08
57 13.32
0.33 is 0.01 is
0.00
--- 0.00
0.00
---
--- 0.012
0.15
115 13.40
0.33 is 0.04 is
0.00
- 0.00
0.00 ---
---
--- 0.041
0.22
172 13.48
0.33 is 0.08 is
0.00
- 0.00
0.00 ---
--- 0.075
0.30
229 13.55
0.33 is 0.10 is
0.00
0.00
0.00
0.099
0.38
287 13.63
0.33 is 0.12 is
0.00
0.00
0.00
---
n_1119
0.45
344 13.70
0.33 is 0.13 is
0.00
--- 0.00
0.00
---
--- 0.135
0.52
401 13.77
0.33 is 0.15 is
0.00
0.00
0.00 --
-
--- 0.149
0.60
459 13.85
0.33 is 0.16 is
0.00
- 0.00
0.00 -
--
0.163
0.68
,l
516 13.93
0.33 is 0.18 is
0.00
- 0.00
0.00 ---
--
--- 0.175
0.75
573 14.00
0.33 is 0.19 ir.
0.00
-- 0.00
0.00 -
--
--- --- 0.187
0.85
1,592 14.10
0.33 is 0.20 is
0.00
-- 0.00
0.00
--
--- --- 0.201
0.95
2,611 14.20
0.33 is 0.21 is
0,00
0.00
0.00
-_- 0.215
1.05
3,630 14.30
0.33 is 0.23 is
0.00
0.00
0.00
0.227
1.15
4,649 14.40
0.33 is 0.24 is
0.00
0.00
_--
0.00
0.239
1.25
5,668 14.50
0.33 is 0.25 is
0.00
0.00
0.00
--
0.251
1.35
6,687 14.60
0.33 is 0.26 is
0.00
--- 0.00
0.00 ---
---
--- 0.262
1.45
7,706 14.70
0.33 is 0.27 is
0.00
0.00
0.00 ---
-
- 0.272
1.55
I
8,725 14.80
0.33 is 0.28 is
0.00
0.00
0.00
i
-__0.282
1.65
9,744 14.90
0.33 is 0.29 is
0.00
0.00
0.00
0.292
1.75
10,763 15.00
0.33 is 0.30 is
0.00
-- 0.00
0.00 ---
-
-- --- 0.301
1.85
13,744 15.10
0.33 is 0.31 ir.
0.00
- 0.00
0.00
--
-- --- 0.310
1.95
16,726 15.20
0.33 is 0.32 is
0.00
0.00
0.00
0.319
2.05
19,707 15.30
0.33 is 0.33 is
0.00
0.00
___
0.00
___
__ ___
0.328
2.15
22,689 15.40
0.37 is 0.34 is
0.00
--- 0.00
0.00 ---
---
--- --- 0.336
2.25
25,670 15.50
0.37 is 0.34 is
0.00
0.00
0.00 ---
--
--- --- 0.345
2.35
28,652 15.60
0.37 Ic 0.35 is
0.00
0.00
0.00 -
--
--- 0.353
2.45
31,633 15.70
0.37 is 0.36 is
0.00
0.00
0.00 ---
--- --- 0.360
2.55
34,614 15.80
0.37 is 0.37 is
0.00
0.00
0.00 ---
--
--- --- 0.368
2.65
37,596 15.90
0.41 is 0.38 is
0.00
--- 0.00
0.00 ---
--
--- --- 0.376
2.75
40,577 16.00
0.41 is 0.38 is
0.00
0.00
0.00 ---
--
--- --- 0.383
2.85
44,996 16.10
0.41 is 0.39 is
0.00
- 0.00
0.00 ---
--
0.390
2.95
49,415 16.20
0.41 is 0.40 is
0.00
--- 0.00
0.00
---
0.397
t 3.05
53,833 16.30
0.41 is 0.40 is
0.00
- 0.00
0.00 ---
--
--- 0.404
3.15
58,252 16.40
0.41 is 0.41 is
0.00
- 0.00
0.00 ---
--
0.411
Continues on next page...

28
Dry Pond
- EAST
Stage /
Storage / Discharge Table
Stage
Storage
Elevation
Civ A
Clv B
Clv C
PrFRSr
Wr A
Wr B
Wr C Wr D EMI
User Total
ft
cuft
ft
cis
cfs
cfs
cis
cis
cfs
cis cis cfs
cfs cfs
3.25
62,671
16.50
0.42 is
0.42 is
0.00
0.00
0.00
-- --
-- 0.418
3.35
67,090
16.60
1.39 oc
0.42 is
0.97 is
0.00
0.00
--- --
-- 1.386
3.45
71,508
16.70
3.26 oc
0.40 is
2.74 is
---
0.00
0.00
--- -
-- 3.143
3.55
75,927
16.80
5.49 oc
0.39 is
5.04 is
---
0.00
0.00
--- ---
5.421
3.65
80,346
16.90
8.21 oc
0.37 is
7.75 is
---
0.00
0.00
--- --- ---
--- 8.118
3.75
84,764
17.00
11.28 oc
0.34 is
10.83 is
---
0.00
0.00
--- ---
-- 11.17
3.85
89,815
17.10
14.60 oc
0.31 is
14.24 is
---
0.00
0.00
--- --- ---
--- 14.55
3.95
94,866
17.20
18.20 oc
0.25 is
17.95 is
--
0.00
0.00
--- --- ---
--- 18.20
4.05
99,918
17.30
22.18 oc
0.25 is
21.93 is
--
0.00
0.00
--- --- ---
--- 22.18
4.15
104,969
17.40
26.41 oc
0.25 is
26.16 is
0.00
0.00
-- --- -
--- 26.41
4.25
110,020
17.50
30.89 oc
0.25 is
30.64 is
--
0.00
0.00
-- -- --
--- 30.89
4.35
115,071
17.60
33.81 oc
0.25 is
33.57 is
-
0.00
0.00
-- --
-- 33.81
4.45
120,122
17.70
36.51 oc
0.25 is
36.26 is
-
0.00
0.00
-- ---
-- 36.50
4.55
125,173
17.80
39.01 oc
0.25 is
38.76 is
---
0.00
0.00
--- -- --
-- 39.01
4.65
130,224
17.90
41.36 oc
0.25 is
41.11 is
---
0.00
0.00
-- --- ---
--- 41.36
4.75
135,275
18.00
43.58 oc
0.25 is
43.33 is
---
0.00
0.00
--- --- --
-- 43.58
4.85
140,909
18.10
46.59 oc
0.24 is
44.24 is
-
2.11
0.00
--- - --
-- 46.59
4.95
146,544
18.20
49.45 oc
0.24 is
43.25 is
--
5.96
0.00
-- ---
--- 49.44
5.05
152,178
18.30
52.70 oc
0.23 is
41.53 is
-
10.94
0.00
--- - --
52.70
5.15
157,813
18.40
56.20 oc
0.21 is
39.14 is
--
16.85
0.00
--- -- ---
--- 56.20
5.25
163,447
18.50
59.81 oc
0.20 is
36.06 is
23.55
0.00
--- --- --
--- 59.81
5.35
169,081
18.60
63.35 oc
0.18 is
32.42 is
30.75 s
4.11
-- --
67.46
5.45
174,716
18.70
65.37 is
0.16 is
29.41 is
35.79 s
11.63
- -- --
- 76.99
5.55
180,350
18.80
66.90 is
0.15 is
26.92 is
39.83 s
21.36
- --- --
-- 88.25
5.65
185,985
18.90
68.25 is
0.14 is
24.81 is
---
43.31 s
32.89
- -- --
101.14
5.75
191,619
19.00
69.48 is
0.13 is
22.98 is
---
46.38 s
45.96
-- --- ---
115.44
5.85
197,852
19.10
70.62 is
0.12 is
21.38 is
---
49.12 s
60.42
--- --- ---
--- 131.03
5.95
204,085
19.20
71.69 is
0.11 is
19.97 is
---
51.61 s
76.14
--- --- --
--- 141.82
6.05
210,318
19.30
72.70 is
0.10 is
18.72 is
---
53.87 s
93.02
--- --- ---
--- 165.71
6.15
216,552
19.40
73.66 is
0.10 is
17.60 is
---
55.95 s
111.00
--- - ---
--- 184.65
6.25
222,785
19.50
74.58 is
0.09 is
16.60 ir.
---
57.89 s
130.00
--- ---
--- 204.58
6.35
229,018
19.60
75.47 is
0.09 is
15.70 is
---
59.67 s
149.98
--- ---
--- 225.43
6.45
235,251
19.70
76.34 is
0.08 is
14.89 is
61.37 s
170.89
- ---
247.22
6.55
241,484
19.80
77.18 is
0.08 is
14.14 is
62.94 s
192.69
---
269.85
6.65
247,717
19.90
78.00 is
0.07 is
13.47 is
64.44 s
215.35
---
--- 293.32
6.75
253,950
20.00
78.80 is
0.07 is
12.86 is
65.87 s
238.83
--- --- --
- 317.62
... End

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil MOD 2019 by Autodesk, Inc. v2019.2
Hyd. No. 20
Post-Dev Outlet B (Detained)
Hydrograph type = Combine
Peak discharge
Storm frequency = 1 yrs
Time to peak
Time interval = 2 min
Hyd. volume
Inflow hyds. = 14, 16
Contrib. drain. area
1.00
0.00
0
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 1 Year
600 1200 1800 2400 3000 3600
Hyd No. 20 Hyd No. 14 Hyd No. 16
29
Sunday, 03 / 7 / 2021
= 1.334 cfs
= 732 min
= 32,653 cuft
= 2.020 ac
4200 4800 5400
Q (cfs
1.00
0.00
6000
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 21
Post-Dev Outlet C (Detained)
Hydrograph type = Combine
Peak discharge
Storm frequency = 1 yrs
Time to peak
Time interval = 2 min
Hyd. volume
Inflow hyds. = 13, 18
Contrib. drain. area
Q (cfs)
2.00
1.00
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 1 Year
30
Sunday, 03 / 7 / 2021
= 1.378 cfs
= 934 min
= 102,873 cuft
= 0.510 ac
480 960 1440 1920 2400 2880 3360 3840 4320
Hyd No. 21 Hyd No. 13 Hyd No. 18
Q (cfs)
2.00
1.00
0.00
4800
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk(D Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 22
Post Out Total (Detained)
31
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 2.553 cfs
Storm frequency
= 1 yrs
Time to peak
= 734 min
Time interval
= 2 min
Hyd. volume
= 140,222 cuft
Inflow hyds.
= 9, 20, 21
Contrib. drain. area
= 2.040 ac
2.00
1.00
Post Out Total (Detained)
Hyd. No. 22 -- 1 Year
600 1200
1800 2400
3000 3600 4200
4800 5400
— Hyd No. 22
— Hyd No. 9
, Hyd No. 20 —
Hyd No. 21
Q (cfs)
3.00
i•-91I17
1.00
0.00
6000
Time (min)

32
Hydrograph Summary Report
ydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
1.271
2
744
9,066
----
-----
Pre DA 1.1 (Outlet A)
2
SCS Runoff
1.564
2
726
8,668
--
Pre DA 1.2
3
SCS Runoff
15.50
2
730
67,075
----
------
Pre DA 1.3 (Outlet C)
4
SCS Runoff
1.720
2
730
7,592
----- ------
----
Pre DA 1.4
6
Combine
3.170
2
728
16,261
2, 4, ------
---
Pre-Dev Outlet B
7
Combine
19.26
2
730
92,402
" "
Pre-Dev TOTAL OUT
9
SCS Runoff
1.482
2
736
7,670
--
--
Post DA 2.1 (Outlet A)
10
SCS Runoff
12.45
2
724
37,311
------
Post DA 2.2
11
SCS Runoff
14.37
2
730
56,192
— —
-----
Post DA 2.3A
12
SCS Runoff
41.40
2
716
83,979
---
Post DA 2.3B
13
SCS Runoff
1.350
2
718
2,702
-----
---
Post DA 2.3C
14
SCS Runoff
2.170
2
730
9,236
--
Post DA 2.4
16
Reservoir
0.872
2
830
37,309
10 1 t.82
22,100
DRY POND - WEST
17
Combine
46.85
2
718
140,171
11, 12, ----
-----
Post Inflow to East Pond
18
Reservoir
4.553
2
776
140,166
17 16.76
74,244
DRY POND - EAST
20
Combine
2.266
2
730
46,546
14, 16,
Post-Dev Outlet B (Detained)
21
Combine
4.640
2
774
142,868
13, 18,
--
Post-Dev Outlet C (Detained)
22
Combine
5.781
2
780
197,083
9, 20, 21
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 2 Year
Sunday, 03 1712021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil MOD 2019 by Autodesk, Inc. v2019.2
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
' Composite (Area/CN) = [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
1.00
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 1
33
Sunday, 03 / 7 / 2021
= 1.271 cfs
= 744 min
= 9,066 cuft
= 50*
= 0 ft
= 17.50 min
= Type III
= 484
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 300 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.620 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74))/4.620
Q (cfs)
1.00
Pre DA 1.2
Hyd. No. 2 -- 2 Year
120 240 360 480 600 720 840
Hyd No. 2
34
Sunday, 03 17 / 2021
= 1.564 cfs
= 726 min
= 8,668 cult
= 50*
= Oft
= 6.40 min
= Type III
= 484
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.470 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
' Composite (Area/CN) = [(1.840 x 98) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 61)] / 15.470
Q (cfs)
15.00
12.00
9.00
6.00
3.00
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 2 Year
35
Sunday, 03/7/2021
= 15.50 cfs
= 730 min
= 67,075 cuft
= 61*
= Oft
= 12.90 min
= Type III
= 484
Q (cfs)
18.00
15.00
12.00
AM
M
3.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3
Time (min)

L
L
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
SCS Runoff
Peak discharge
Storm frequency
2 yrs
Time to peak
Time interval
2 min
Hyd. volume
Drainage area
1.850 ac
Curve number
Basin Slope
0.0 %
Hydraulic length
Tc method
TR55
Time of conc. (Tc)
Total precip.
4.64 in
Distribution
Storm duration
24 hrs
Shape factor
' Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Q (cfs)
1.00
Pre DA 1.4
Hyd. No. 4 -- 2 Year
36
Sunday, 03 17 12021
= 1.720 cfs
= 730 min
= 7,592 cuft
= 60*
= Oft
= 12.30 min
= Type III
= 484
Q (cfs)
2.00
1.00
0.00 -' 1 1 1 1 1 J 1 1—. _ I i_ L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 6
Pre-Dev Outlet B
37
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 3.170 cfs
Storm frequency
= 2 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 16,261 cuff
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
3.00
2.00
1.00
Pre-Dev Outlet B
Hyd. No. 6 -- 2 Year
Q (cfs)
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 Hyd No. 2 Hyd No. 4

Hydrograph Report 38
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 0317 / 2021
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type
= Combine
Peak discharge
= 19.26 cfs
Storm frequency
= 2 yrs
Time to peak
= 730 min
Time interval
= 2 min
Hyd. volume
= 92,402 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
Q (cfs)
21.00
I
i 18.00
I
15.00
12.00
9.00
6.00
3.00
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 2 Year
Q (cfs)
21.00
18.00
15.00
12.00
9.00
6.00
3.00
0.00 1 i I I », �.� L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 Hyd No. 3 � Hyd No. 6

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.040 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) - [(0.690 x 98) + (1.350 x 39)] / 2.040
1.00
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 2 Year
120 240 360 480 600 720 840
Hyd No. 9
39
Sunday, 03 / 7 / 2021
= 1.482 cfs
= 736 min
= 7,670 cuft
= 59*
= 0 ft
= 16.70 min
= Type III
= 484
Q (cfs)
2.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 10
Post DA 2.2
40
Sunday, 03 / 7 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 12.45 cfs
Storm frequency
= 2 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 37,311 cuft
Drainage area
= 4.890 ac
Curve number
= 76*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 4.64 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
Post DA 2.2
Q WS) Hyd. No. 10 -- 2 Year
14.00 -
12.00
10.00
6.00
4.00
WE
Q (cfs)
14.00
12.00
10.00
8.00
MM
4.00
2.00
0.00 -1 1 1 1 1 1 1 1 1- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 10
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.800 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] 17.800
Q (cfs)
15.00
12.00
I 9.00
I
I 6.00
I
I
3.00
0.00
0
I
Post DA 2.3A
Hyd. No. 11 -- 2 Year
41
Sunday, 03 17 / 2021
= 14.37 cfs
= 730 min
= 56,192 cuft
= 72*
= 0 ft
= 12.90 min
= Type III
= 484
Q (cfs)
15.00
12.00
We'
. Me
3.00
- 0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 31382019 by Autodesk, Inc. v2019.2
Hyd. No. 12
Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 9.560 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
0
Post DA 2.3113
Hyd. No. 12 -- 2 Year
42
Sunday, 03 1712021
= 41.40 cfs
= 716 min
= 83,979 cuft
= 80
= Oft
= 5.00 min
= Type II
= 484
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 12 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 0.510 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 4.64 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q WS)
2.00
1.0(
Post DA 2.3C
Hyd. No. 13 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 13
43
Sunday, 03 / 7 / 2021
= 1.350 cfs
= 718 min
= 2,702 tuft
= 67
= 0 ft
= 5.00 min
= Type II
= 484
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph
Report
44
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
= 2.170 cfs
Storm frequency
= 2 yrs
Time to peak
= 730 min
Time interval
= 2 min
Hyd. volume
= 9,236 cuft
Drainage area
= 2.020 ac
Curve number
= 62*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 12.30 min
Total precip.
= 4.64 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
2.00
1.00
Post DA 2.4
Hyd. No. 14 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 14
Q (cfs)
3.00
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
HY hlydFKVaPhs Extension for AuWdwk@ Chit 3 2919 by Autodesk. Inc. vM19.2
Hyd. No. 16
DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Wow hyd. No.
= 10 - Post DA 2.2
Max. Elevation
Reservoir name
= Dry Pond - W EST
Max. Storage
Storage Indication medal used.
Q (cfs)
14.00
12.00
10.00
8.00
M.
4.00
2.00
600
Hyd No. 16
DRY POND - WEST
Hyd. No. 16 — 2 Year
45
Sunday, 0317 12021
= 0.872 cis
= 830 min
= 37,309 cult
_ '17.82 ft
= 22,100 tuft
Q (Cfs)
14.00
12.00
10.00
ME(
6.00
4.00
U
L.0®
1200 1800 2400 3000 3600 4200 4800 5400 6000
-- Hyd No. 10 Total storage used = 22,100 cuR Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
Storm frequency
= 2 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyds.
= 11, 12
Contrib. drain. area
40.00
30.00
20.00
10.00
Post Inflow to East Pond
Hyd. No. 17 -- 2 Year
120 240 360 480 600 720
Hyd No. 17 Hyd No. 11
46
Sunday, 03 / 7 / 2021
= 46.85 cfs
= 718 min
= 140,171 cuft
= 17.360 ac
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
840 960 1080 1200 1320 1440 1560
- Hyd No. 12 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodeskl9 Civic 3DV 2019 by Autodesk, Inc. v2019.2
Hyd. No. 18
DRY POND - EAST
Hydrograph type
= Reservoir
Peale discharge
Storm frequency
= 2 yrs
Time to peals
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 17 - Post Inflow to ,East Pond
Max. Elevation
Reservoir name
= Dry Pond -EAST
Max. Storage
storage Indication method used.
Q WS)
50.00
40.00
20.00
10.00
0.Od
0
DRY POND - EAST
Hyd. No. 18 — 2 Year
47
Sunday. 0317 f 2021
= 4.553 cfs
= 776 min
= 140,166 cult
= 16.7£ ft
= 74,244 cult
r
f
i
�
�
1
!
1
e
I
1r
480 960 1440 1920 2400
Hyd No. 18 Hyd No. 17
Q (cfs)
50.00
40.00
30.00
20.00
10.00
�- 0.00
2880 3360 3840 4320 4800
Time (min)
Total storage used = 74,244 cuff

Hydrograph Report
48
Hydreflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 20
Post-Dev Outlet B (Detained)
Hydrograph type = Combine
Peak discharge
= 2.266 cfs
Storm frequency = 2 yrs
Time to peak
= 730 min
Time interval = 2 min
Hyd. volume
= 46,546 cuft
Inflow hyds. = 14, 16
Contrib. drain. area
= 2.020 ac
2.00
1.00
1.
L
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 2 Year
600 1200 1800 2400 3000 3600 4200 4800 5400
Hyd No. 20 Hyd No. 14 Hyd No. 16
Q (cfs)
3.00
rW
1.00
0.00
6000
Time (min)

Hydrograph Report 49
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 21
Post-Dev Outlet C (Detained)
Hydrograph type
= Combine
Peak discharge
= 4.640 cfs
Storm frequency
= 2 yrs
Time to peak
= 774 min
Time interval
= 2 min
Hyd. volume
= 142,868 cuft
Inflow hyds.
= 13, 18
Contrib. drain. area
= 0.510 ac
Q (cfs)
5.00
4.00
3.00
2.00
1.00
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 2 Year
480 960 1440 1920 2400 2880 3360 3840 432(
Hyd No. 21 Hyd No. 13 Hyd No. 18
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
4800
Time (min)

Hydrograph Report
50
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 22
Post Out Total (Detained)
Hydrograph type = Combine
Peak discharge
= 5.781 cfs
Storm frequency = 2 yrs
Time to peak
= 780 min
Time interval = 2 min
Hyd. volume
= 197,083 cuft
Inflow hyds. = 9, 20, 21
Contrib. drain. area
= 2.040 ac
Q (cfs)
5.00
4.00
3.00
WC
1.00
480 960
Hyd No. 22
Post Out Total (Detained)
Hyd. No. 22 -- 2 Year
Q (cfs)
6.00
5.00
4.00
3.00
r M
1.00
0.00
1440 1920 2400 2880 3360 3840 4320 4800 5280
Hyd No. 9 Hyd No. 20 Hyd No. 21 Time (min)

51
Hydrograph Summary Repo rlydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(tuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(tuft)
Hydrograph
Description
1
SCS Runoff
3.427
2
738
18,873
----
------
Pre DA 1.1 (Outlet A)
2
SCS Runoff
4.704
2
726
18,045
----
Pre DA 1.2
3
SCS Runoff
28.97
2
730
116,529
--
---
Pre DA 1.3 (Outlet C)
4
SCS Runoff
3.293
2
730
13,353
-----
------
----
Pre DA 1.4
6
Combine
7.674
2
726
31,398
2, 4,
-----
Pre-Dev Outlet B
7
Combine
38.43
2
730
166,800
--
Pre-Dev TOTAL OUT
9
SCS Runoff
2.891
2
734
13,663
-----
Post DA 2.1 (Outlet A)
10
SCS Runoff
18.86
2
724
56,393
------
Post DA 2.2
11
SCS Runoff
22.76
2
728
87,637
----
Post DA 2.3A
12
SCS Runoff
60.07
2
716
123,312
--
Post DA 2.3B
13
SCS Runoff
2.196
2
718
4,404
---
------
Post DA 2.3C
14
SCS Runoff
3.970
2
730
15,859
----
----
Post DA 2.4
16
Reservoir
4.031
2
750
56,391
10
26,339
DRY POND - WEST
17
Combine
68.89
2
718
210,950
11, 12,
--
Post Inflow to East Pond
18
Reservoir
17.14
:
744
210,945
17
17.11
93,398
DRY POND - EAST
20
Combine
6.225
i
3
72,251
14, 16,
----
------
Post-Dev Outlet B (Detained)
21
Combine
17.37
t
- 215,349
13, 18,
----
Post-Dev Outlet C (Detained)
22
Combine
26.06
2
301,262
9, 20, 21
—
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 5 Year
Sunday, 03 / 7 / 2021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
I
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
Q (cfs)
4.00 —
3.00
2.00
1.00
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 5 Year
52
Sunday, 03 / 7 / 2021
= 3.427 cfs
= 738 min
= 18,873 cuft
= 50*
= 0 ft
= 17.50 min
= Type III
= 484
Q (cfs)
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.620 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74)] 14.620
Q (cfs)
5.00
4.00
3.00
2.00
1.00
Pre DA 1.2
Hyd. No. 2 -- 5 Year
53
Sunday, 03 / 7 / 2021
= 4.704 cfs
= 726 min
= 18,045 cuft
= 50*
= 0 ft
= 6.40 min
= Type III
= 484
Q (cfs)
5.00
4.00
3.00
99
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.470 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
*Composite (Area/CN) = [(1.840 x 98) + (5.710 x 55) + (0.260x70) + (1.740 x 39) + (5.920 x 61)] / 15.470
25.00
20.00
15.00
10.00
5.00
54
Sunday, 03 / 7 / 2021
= 28.97 cfs
= 730 min
= 116,529 cult
= 61*
= 0 ft
= 12.90 min
= Type III
= 484
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 5 Year
Q (cfs)
30.00
25.00
20.00
15.00
10.00
5.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 1.850 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Q (cfs)
4.00
3.00
t
I 2.00
1.00
Pre DA 1.4
Hyd. No. 4 -- 5 Year
55
Sunday, 03 / 7 / 2021
= 3.293 cfs
= 730 min
= 13,353 cuft
= 60*
= Oft
= 12.30 min
= Type III
= 484
Q (cfs)
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 6
Pre-Dev Outlet B
56
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 7.674 cfs
Storm frequency
= 5 yrs
Time to peak
= 726 min
Time interval
= 2 min
Hyd. volume
= 31,398 cuft
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
Q (cfs)
8.00
6.00
4.00
2.00
Pre-Dev Outlet B
Hyd. No. 6 -- 5 Year
Q (cfs)
8.00
6.00
4.00
2.00
0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 6 Hyd No. 2 , Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type = Combine Peak discharge
Storm frequency = 5 yrs Time to peak
Time interval = 2 min Hyd. volume
Inflow hyds. = 1, 3,6 Contrib. drain. area
Q (cfs)
40.00
30.00
10.00
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 5 Year
120 240 360 480 600 720 840
Hyd No. 7 Hyd No. 1
57
Sunday, 03 / 7 / 2021
= 38.43 cfs
= 730 min
= 166,800 cuft
= 20.000 ac
40.00
30.00
20.00
10.00
0.00
960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 6

Hydrograph Report
58
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type = SCS Runoff
Peak discharge
= 2.891 cfs
Storm frequency = 5 yrs
Time to peak
= 734 min
Time interval = 2 min
Hyd. volume
= 13,663 cuft
Drainage area = 2.040 ac
Curve number
= 59*
Basin Slope = 0.0 %
Hydraulic length
= 0 ft
Tc method = TR55
Time of conc. (Tc)
= 16.70 min
Total precip. = 6.01 in
Distribution
= Type III
Storm duration = 24 hrs
Shape factor
= 484
* Composite (Area/CN) _ [(0.690 x 98) + (1.350 x 39)] / 2.040
2.00
1.00
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 5 Year
Q (cfs)
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 9 Time (min)

i Hydrograph
Report
59
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
= 18.86 cfs
Storm frequency
= 5 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 56,393 cuft
Drainage area
= 4.890 ac
Curve number
= 76*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 6.01 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
Post DA 2.2
Hyd. No. 10 -- 5 Year
15.00
i
12.00
9.00
6.00
f
i
3.00
Q (cfs)
21.00
18.00
15.00
12.00
WE
1M.
0.00 1 1 1 1_ I i i i I I I L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 10 Time (min)

Hydrograph
i
Report
60
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 11
Post DA 2.3A
i
Hydrograph type
= SCS Runoff
Peak discharge
= 22.76 cfs
Storm frequency
= 5 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 87,637 cuft
Drainage area
= 7.800 ac
Curve number
= 72*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 12.90 min
Total precip.
= 6.01 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] 17.800
Q (cfs)
24.00 —
I
20.00
16:00
12.00
8.00
4.00
Post DA 2.3A
Hyd. No. 11 -- 5 Year
Q (cfs)
24.00
20.00
16.00
12.00
M
4.00
0.00 1 1 1 1 _1r" i i 1 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 12
Post DA 2.3B
i
61
Sunday, 03 / 7 12021
i Hydrograph type
= SCS Runoff
Peak discharge
= 60.07 cfs
Storm frequency
= 5 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 123,312 cuft
Drainage area
= 9.560 ac
Curve number
= 80
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 6.01 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post DA 2.313
Q (cfs) Hyd. No. 12 -- 5 Year Q (Cfs)
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 - — 20.00
10.00 10.00
I
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 12
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 0.510 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
3.00 T-
2.00
1.00
M
Post DA 2.3C
Hyd. No. 13 -- 5 Year
I
62
Sunday, 03 / 7 / 2021
= 2.196 cfs
= 718 min
= 4,404 tuft
= 67
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 13
Time (min)

Hydrograph Report
I
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 5 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.020 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 6.01 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
3.00
1.00
63
Sunday, 03 / 7 / 2021
= 3.970 cfs
= 730 min
= 15,859 cuft
= 62*
= Oft
= 12.30 min
= Type III
= 484
Post DA 2.4
Hyd. No. 14 -- 5 Year
Q (cfs)
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14 Time (min)
L

Hydrograph Report
64
Hydraflow Hydmgraphs Extension for AutodeskV Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday. 03 / 7 / 2021
I
Hyd. No. 16
DRY POND - WEST
I Hydrograph type
= Reservoir
Pear discharge
= 4.031 cfs
Storm frequency
= 5 yrs
Time to peak
= 750 min
Time interval
= 2 min
Hyd. volume
= 56,391 cult
Inflow hyd. No.
= 10 -Post DA 2.2
Max. Elevation
= 18.11 ft
Reservoir name
= Dry Pond -WEST
Max. Storage
= 26,339 tuft
Storage Indicabw method used.
I
i
I
DRY POND - WEST
�c) Hyd. No. 16 — 5 Year
21.00
18.00
15.00
12.00
I
9.00
6.00
3.00
I
i
i
1
�
I
�
I
i
�
1
1
1
I
�
i
i
s
ii
Q (cts)
21.00
18.00
15.00
12.00
9.00
6.00
3.00
0.00 0.00
0 480 960 1440 1920 2400 2880 3360 3840 4320 4800 5280 5760
Time (min)
--- Hyd No. 16 -- Hyd No. 10 Total storage used = 26,339 cult

Hydrograph
Report
65
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 17 / 2021
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
= 68.89 cfs
Storm frequency
= 5 yrs
Time to peak
= 718 min
Time interval
= 2 min
Hyd. volume
= 210,950 tuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
60.00
50.00
40.00
30.00
20.00
10.00
Post Inflow to East Pond
Hyd. No. 17 -- 5 Year
Q (cfs)
70.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 17 Hyd No. 11 Hyd No. 12 Time (min)

Hydr©graph Report
tS
Hydraflnw Hydm9whs Extension
for AutodesM Civil 3138 2019 by Autodesk, Inc. v2019.2
Sunday, 03 17 ! 2021
Hyd. No. 18
DRY POND - EAST
Hydrograph tyke
=Reservoir
Peak discharge
= 17.14 cis
Storm frequency
= 5 yrs
Time to peak
= 744 min
Time interval
= 2 min
Hyd. volume
= 210,945 cuff
Inflow hyd. No.
= 17 - Post Inflow to East Pond
Max. Elevation
= 17.17 ft
Reservoir name
= Dry Pond -EAST
Max. Storage
= 93,398 cult
Stomp Indicabon metiwd used.
DRY POND - EAST
Q (ds) Hyd. No. 18 — 5 Year Q (S)
70.00
70.00
1
60.00 60.00
I � i
50.00 50.00
a
a 1
y
40.00 40.00
d P
� I
I
30.00 30.00
20.00 �
—__.
20.00
1
10.00 10.00
0.00 - 0.00
0 480 960 1440 1920 2400 2880 3360 3840 4320 4800
Time (min)
--- Hyd No. 18 -- Hyd No. 17 Total storage used = 93,398 cuff

Hydrograph Report
67
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 20
Post-Dev Outlet B (Detained)
Hydrograph type = Combine
Peak discharge
= 6.225 cfs
Storm frequency = 5 yrs
Time to peak
= 738 min
Time interval = 2 min
Hyd. volume
= 72,251 cuft
Inflow hyds. = 14, 16
Contrib. drain. area
= 2.020 ac
Q (cfs)
r .00
6.00
5.00
4.00
3.00
2.00
1.00
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 5 Year
Q (Cfs)
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
0.00
0 480 960 1440 1920 2400 2880 3360 3840 4320 4800 5280
Hyd No. 20 — Hyd No. 14 , Hyd No. 16 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 21
Post-Dev Outlet C (Detained)
68
Sunday, 03 17 / 2021
Hydrograph type
= Combine
Peak discharge
= 17.37 cfs
Storm frequency
= 5 yrs
Time to peak
= 744 min
Time interval
= 2 min
Hyd. volume
= 215,349 cuft
Inflow hyds.
= 13, 18
Contrib. drain. area
= 0.510 ac
15.00
12.00
'M
M
3.00
480 960
— Hyd No. 21
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 5 Year
Q (cfs)
18.00
15.00
12.00
MM
M
3.00
0.00
1440 1920 2400 2880 3360 3840 4320 4800
Hyd No. 13 Hyd No. 18 Time (min)

Hydrograph Report 69
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 12021
Hyd. No. 22
Post Out Total (Detained)
Hydrograph type = Combine Peak discharge = 26.06 cfs
Storm frequency = 5 yrs Time to peak = 742 min
Time interval = 2 min Hyd. volume = 301,262 cuft
Inflow hyds. = 9, 20, 21 Contrib. drain. area = 2.040 ac
24.00
20.00
16.00
12.00
8.00
4.00
480 960
Hyd No. 22
Post Out Total (Detained)
Hyd. No. 22 -- 5 Year
Q (cfs)
28.00
24.00
20.00
16.00
12.00
8.00
4.00
0.00
1440 1920 2400 2880 3360 3840 4320 4800
Hyd No. 9 Hyd No. 20 Hyd No. 21 Time (min)

70
Hydrograph Summary Repo rlydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
5.875
2
736
29,346
-----
------
Pre DA 1.1 (Outlet A)
2
SCS Runoff
8.264
2
724
28,058
----
------
----
Pre DA 1.2
3
SCS Runoff
42.08
2
730
165,304
---
------
------
Pre DA 1.3 (Outlet C)
4
SCS Runoff
4.834
2
730
19,067
----
----
----
Pre DA 1.4
6
Combine
12.43
2
726
47,126
2, 4,
--
---
Pre-Dev Outlet B
7
Combine
57.88
2
728
241,776
1, 3, 6
-
----
Pre-Dev TOTAL OUT
9
SCS Runoff
4.308
2
734
19,644
---
-----
Post DA 2.1 (Outlet A)
10
SCS Runoff
24.64
2
724
73,967
----
-----
Post DA 2.2
11
SCS Runoff
30.53
2
728
117,047
------
Post DA 2.3A
12
SCS Runoff
76.61
2
716
159,046
----
---
Post DA 2.313
13
SCS Runoff
2.987
2
716
6,032
---
----
Post DA 2.3C
14
SCS Runoff
5.712
730
22,355
---
------
Post DA 2.4
16
Reservoir
6.352
746
73,965
10
18.48
32,427
DRY POND - WEST
17
Combine
88.65
716
276,093
11, 12,
Post Inflow to East Pond
18
Reservoir
30.75
738
276,088
17
1
109,859
DRY POND - EAST
20
Combine
11.02
732
96,320
14, 16,
-----
Post-Dev Outlet B (Detained)
21
Combine
31.10
738
282,119
13, 18,
------
Post-Dev Outlet C (Detained)
22
Combine
45.98
736
398,084
9, 20, 21
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 10 Year
Sunday, 03 / 7 / 2021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) _ [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
Q (cfs)
5.00
4.00
3.00
1.00
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 10 Year
71
Sunday, 03 / 7 / 2021
= 5.875 cfs
= 736 min
= 29,346 cuft
= 50*
= 0 ft
= 17.50 min
= Type III
= 484
Q (cfs)
6.00
Me
4.00
c 1t
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.620 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) [(0.680 x 30) + (3.200 x 55) + (0.l40 x 70) + (0.470 x 39) + (0.100 x 6l) + (0.030 x 74)] / 4.620
Q (cfs)
QI
6.00
4.00
2.00
Pre DA 1.2
Hyd. No. 2 -- 10 Year
72
Sunday, 03 / 7 / 2021
= 8.264 cfs
= 724 min
= 28,058 cuft
= 50*
= Oft
= 6.40 min
= Type III
= 484
Q (cfs)
10.00
M
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No 2 Time (min)

Hydrograph
Report
73
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 12021
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
= 42.08 cfs
Storm frequency
= 10 yrs
Time to peak
= 730 min
Time interval
= 2 min
Hyd. volume
= 165,304 cuft
Drainage area
= 15.470 ac
Curve number
= 61*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 12.90 min
Total precip.
= 7.21 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
" Composite (Area/CN) = [(1.840 x 98) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 61)] / 15.470
i
Pre DA 1.3 (Outlet C)
(S) Hyd. No. 3 -- 10 Year Q (afS)
50.00 �— 50.00
40.00
30.00
20.00
10.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 1.850 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)]11.850
Q (cfs)
4.00
3.00
2.00
1.00
Pre DA 1.4
Hyd. No. 4 -- 10 Year
74
Sunday, 03 17 / 2021
= 4.834 cfs
= 730 min
= 19,067 cuft
= 60*
= 0 ft
= 12.30 min
= Type III
= 484
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph
Report
75
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 6
Pre-Dev Outlet B
Hydrograph type
= Combine
Peak discharge
= 12.43 cfs
Storm frequency
= 10 yrs
Time to peak
= 726 min
Time interval
= 2 min
Hyd. volume
= 47,126 cuft
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
E
Q (cfs)
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
0
Pre-Dev Outlet B
Hyd. No. 6 -- 10 Year
Q (cfs)
14.00
12.00
10.00
KI
6.00
4.00
f• i
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 Hyd No. 2 Hyd No. 4

Hydrograph
Report
76
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type
= Combine
Peak discharge
= 57.88 cfs
Storm frequency
= 10 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 241,776 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
Q (cfs)
50.00
40.00
30.00
20.00
10.00
l
L
M
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 10 Year
Q (cfs)
60.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 Hyd No. 3 Hyd No. 6

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.040 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) _ [(0.690 x 98) + (1.350 x 39)] / 2.040
Q (cfs)
4.00
3.00
2.00
1.00
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 10 Year
120 240 360 480 600 720
Hyd No. 9
77
Sunday, 03 / 7 / 2021
= 4.308 cfs
= 734 min
= 19,644 cuft
= 59*
= 0 ft
= 16.70 min
= Type III
= 484
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.890 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) = [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
24.00
20.00
16.00
12.00
8.00
4.00
78
Sunday, 03 / 7 / 2021
= 24.64 cfs
= 724 min
= 73,967 cuft
= 76*
= Oft
= 5.00 min
= Type III
= 484
Post DA 2.2
Hyd. No. 10 -- 10 Year
Q (cfs)
28.00
24.00
20.00
16.00
12.00
8.00
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 10
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
79
Sunday, 03 17 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 30.53 cfs
Storm frequency
= 10 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 117,047 cuft
Drainage area
= 7.800 ac
Curve number
= 72*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 12.90 min
Total precip.
= 7.21 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] / 7.800
Q (cfs)
35.00
30.00
25.00
20.00
,I
15.00
10.00
5.00
Post DA 2.3A
Hyd. No. 11 -- 10 Year
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00 -I 1 1 1 1 1 i .. i i i I i
L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11 Time (min)

Hydrograph Report 80
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 12021
Hyd. No. 12
Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
= 76.61 cfs
Storm frequency
= 10 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 159,046 cuft
Drainage area
= 9.560 ac
Curve number
= 80
Basin Slope
= 0.0 %
Hydraulic length
= Oft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 7.21 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
Post DA 2.313
Hyd. No. 12 -- 10 Year
Q (cfs)
80.00
70.00
60.00
50.00
40.00
30.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 12 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 0.510 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
Q (cfs)
3.00
2.00
1.00
Post DA 2.3C
Hyd. No. 13 -- 10 Year
120 240 360 480 600 720 840 960
Hyd No. 13
81
Sunday, 03 / 7 / 2021
= 2.987 cfs
= 716 min
= 6,032 cuft
= 67
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
3.00
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.020 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 7.21 in
Distribution
Storm duration
= 24 hrs
Shape factor
*Composite (Area/CN) [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
5.00
4.00
3.00
2.00
1.00
82
Sunday, 03 / 7 / 2021
= 5.712 cfs
= 730 min
= 22,355 cuft
= 62*
= Oft
= 12.30 min
= Type III
= 484
Post DA 2.4
Hyd. No. 14 -- 10 Year
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14
Time (min)

Hydrog� aph Report
$3
E Hydraffaw Hydrographs Extension
for AutodeskJ Civil 3M 2019 by Autmdesk, Inc. v2019.2
Sunday. 0317 / 2021
Hyd. No. 1 6
DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
= 6.352 cfs
Storm frequency
= 10 yrs
Time to peak
= 746 min
Time interval
= 2 min
Hyd. volume
= 73,965 cult
Inflow hyd. No.
= 10 - Post DA 2.2
Max. Elevation
= 18.48 ft
Reservoir name
= Dry Pond -WEST
Max. Storage
= 32,427 tuft
Storage Indication mettW used.
DRY POND - !NEST
Q WS) Hyd. No. 16 —10 Year a (ds)
28A0
24.00
20.00
16.00
12.00
8.00
4.00
0.00
28.00
24.00
20.00
16.00
12.00
8.00
4.00
0 00
0 480 960 1440 1920 2400 2880 3360 3840 4320 4800 5280
Time (train)
Hyd No. 16 Hyd No. 10 Total storage used = 32,427 cult

Hydrograph
Report
84
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
= 88.65 cfs
Storm frequency
= 10 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 276,093 cuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
Post Inflow to East Pond
Hyd. No. 17 -- 10 Year
80.00
70.00
'60.00
50.00
40.00
30.00
20.00
10.00
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00 -f 1 1 1 1— 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 17 Hyd No. 11 Hyd No. 12 Time (min)

Hydrograph Report $5
HydraBow Hydrographs Extension for Autodesk3) Civil 3D@ 2019 by Autodesk, Inc. VM19.2
Sunday. 031712W I
Hyd. No. 18
DRY POND - EAST
Hydrograph type
= Reservoir
Peak discharge
= 30.75 cfs
Storm frequency
= 10 yrs
Time to peak
= 738 min
Time interval
= 2 min
Hyd. volume
= 276,088 cult
Inflow hyd. No.
= 17 - Post Inflow to East Pond
Max. Elevation
= 17.50 ft
Reservoir name
= Dry Pond - EAST
Max. Storage
= 109,859 tuft
Storage Indication anethod used.
Q {cis;
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
DRY POND - EAST
Hyd. No. 18 --10 Year
a f i E
i
1 ,
r
9 � A
qq
a
1 �
3
i
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00 --- - - 0.00
0 360 720 1080 1440 1800 2160 2520 2880 3240 3600 3960
Time (min)
Hyd No. 18 -- Hyd No. 17 Total storage used=109,869 cuff

Hydrograph Report
86
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 03 17 / 2021
Hyd. No. 20
Post-Dev Outlet B (Detained)
Hydrograph type = Combine
Peak discharge
= 11.02 cfs
Storm frequency = 10 yrs
Time to peak
= 732 min
Time interval = 2 min
Hyd. volume
= 96,320 cuft
Inflow hyds. = 14, 16
Contrib. drain. area
= 2.020 ac
10.00
8.00
WC
4.00
2.00
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 10 Year
Q (cfs)
12.00
10.00
8.00
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 20 Hyd No. 14 ,Hyd No. 16 Time (min)

Hydrograph Report 87
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 21
Post-Dev Outlet C (Detained)
Hydrograph type = Combine Peak discharge = 31.10 cfs
Storm frequency = 10 yrs Time to peak = 738 min
Time interval = 2 min Hyd. volume = 282,119 cuft
Inflow hyds. = 13, 18 Contrib. drain. area = 0.510 ac
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
0
360 720
Hyd No. 21
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 10 Year
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
1080 1440 1800 2160 2520 2880 3240 3600 3960
Hyd No. 13 Hyd No. 18 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 22
Post Out Total (Detained)
Hydrograph type = Combine
Peak discharge
Storm frequency = 10 yrs
Time to peak
Time interval = 2 min
Hyd. volume
Inflow hyds. = 9, 20, 21
Contrib. drain. area
Q (cfs)
50.00 —
40.00
30.00
9MM
10.00
0.00
0 240 480
Hyd No. 22
Post Out Total (Detained)
Hyd. No. 22 -- 10 Year
88
Sunday, 03 17 / 2021
n
= 45.98 cfs
= 736 min
= 398,084 cuft
= 2.040 ac
Q (cfs)
50.00
40.00
30.00
20.00
10.00
-- 0.00
720 960 1200 1440 1680 1920 2160 2400 2640 2880
Hyd No. 9 Hyd No. 20 Hyd No. 21 Time (min)

89
Hydrograph Summary Repo rlydraflowHydrographsExtension for Autodesk® Civil 3D®2019byAutodesk,Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(tuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(tuft)
Hydrograph
Description
1
SCS Runoff
10.28
2
734
48,044
--
-----
Pre DA 1.1 (Outlet A)
2
SCS Runoff
14.57
2
724
45,936
----
------
Pre DA 1.2
3
SCS Runoff
63.97
2
728
247,372
-----
---
Pre DA 1.3 (Outlet C)
4
SCS Runoff
7.407
2
728
28,725
-----
---
Pre DA 1.4
6
Combine
20.67
2
726
74,661
2, 4,
-----
Pre-Dev Outlet B
7
Combine
91.16
2
728
370,077
4 C
------
Pre-Dev TOTAL OUT
9
SCS Runoff
6.685
2
734
29,800
------
Post DA 2.1 (Outlet A)
10
SCS Runoff
33.68
2
724
102,031
---
---
Post DA 2.2
11
SCS Runoff
42.87
2
728
164,562
---
-----
Post DA 2.3A
12
SCS Runoff
102.15
2
716
215,540
-----
----
Post DA 2.3B
13
SCS Runoff
4.293
2
716
8,705
-----
----
Post DA 2.3C
14
SCS Runoff
8.615
1
728
33,237
----
Post DA 2.4
16
Reservoir
9.034
2
744
102,030
10
43,686
DRY POND - WEST
17
Combine
119.75
2
716
380,102
11, 12,
-----
Post Inflow to East Pond
18
Reservoir
46.57
2
734
380,097
17
18.1u
140,880
DRY POND - EAST
20
Combine
16.97
2
730
135,267
14, 16,
Post-Dev Outlet B (Detained)
21
Combine
47.12
2
734
388,803
13, 18,
--
Post-Dev Outlet C (Detained)
22
Combine
70.29
2
732
553,869
9, 20, 21
----
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 25 Year
Sunday, 03 / 7 / 2021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) _ [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)) / 4.530
Q (cfs)
12.00
10.00
"
Me]
4.00
r 1i
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 25 Year
90
Sunday, 03 17 / 2021
= 10.28 cfs
= 734 min
= 48,044 cuft
= 50*
= Oft
= 17.50 min
= Type III
= 484
Q (cfs)
12.00
10.00
8.00
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3170 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.620 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of cons. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74)] / 4.620
Q (cfs)
15.00 —
12.00
6.00
i 11
Pre DA 1.2
Hyd. No. 2 -- 25 Year
91
Sunday, 03 / 7 / 2021
= 14.57 cfs
= 724 min
= 45,936 cuft
= 50"
= Oft
= 6.40 min
= Type III
= 484
Q (cfs)
15.00
12.00
6.00
3.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No 2 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.470 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) [(1.840 x 98) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 6l )] / l5.470
Q (Cfs)
60.00
50.00
40.00
30.00
1 11
10.00
0.00
0
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 25 Year
92
Sunday, 03 / 7 / 2021
= 63.97 cfs
= 728 min
= 247,372 cuft
= 61*
= Oft
= 12.90 min
= Type III
= 484
Q (cfs)
70.00
50.00
40.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 1.850 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = ((0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Q (cfs)
a nr%
MM
4.00
YX
0.00
0
Pre DA 1.4
Hyd. No. 4 -- 25 Year
93
Sunday, 03 / 7 / 2021
= 7.407 cfs
= 728 min
= 28,725 cuft
= 60*
= Oft
= 12.30 min
= Type III
= 484
Q (cfs)
8.00
. 11
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph
Report
94
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 6
Pre-Dev Outlet B
Hydrograph type
= Combine
Peak discharge
= 20.67 cfs
Storm frequency
= 25 yrs
Time to peak
= 726 min
Time interval
= 2 min
Hyd. volume
= 74,661 cuft
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
Q (cfs)
21.00
18.00
15.00
12.00
9.00
6.00
3.00
Pre-Dev Outlet B
Hyd. No. 6 -- 25 Year
Q (cfs)
21.00
18.00
15.00
12.00
M
6.00
3.00
0.00 -I 1 1 1 1 _- 1 - L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 Hyd No. 2 ' Hyd No. 4

Hydrograph
Report
95
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type
= Combine
Peak discharge
= 91.16 cfs
Storm frequency
= 25 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 370,077 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
Pre-Dev TOTAL OUT
Q (Cfs) Hyd. No. 7 -- 25 Year Q (Cfs)
100.00 100.00
90.00 90.00
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
{
10.00
�i
10.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 I Hyd No. 3 Hyd No. 6

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2019.2
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.040 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
*Composite (Area/CN) _ [(0.690 x 98) + (1.350 x39)]12.040
6.00
5.00
4.00
3.00
2.00
1.00
96
Sunday, 03 / 7 / 2021
= 6.685 cfs
= 734 min
= 29,800 cuft
= 59*
= Oft
= 16.70 min
= Type III
= 484
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 25 Year
Q (cis)
7.00
Am
5.00
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 9 Time (min)

Hydrograph
Report
97
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
= 33.68 cfs
Storm frequency
= 25 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 102,031 cuft
Drainage area
= 4.890 ac
Curve number
= 76*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 9.06 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
Post DA 2.2
Hyd. No. 10 -- 25 Year
30.00
25.00
20.00
15.00
10.00
5.00
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
4 11
0.00 - I I I I I I _L i 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 10 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 25 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.800 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 9.06 in
Distribution
Storm duration
= 24 hrs
Shape factor
` Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] / 7.800
Q (cfs)
50.00
40.00
30.00
20.00
10.00
Post DA 2.3A
Hyd. No. 11 -- 25 Year
98
Sunday, 03 / 7 12021
= 42.87 cfs
= 728 min
= 164,562 cuft
= 72*
= 0 ft
= 12.90 min
= Type III
= 484
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11
Time (min)

r
Hydrograph
Report
99
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 12
I Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
= 102.15 cfs
Storm frequency
= 25 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 215,540 cuft
Drainage area
= 9.560 ac
Curve number
= 80
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 9.06 in
Distribution
= Type II
j Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
120.00
100.00
-80.00
60.00
40.00
20.00
Post DA 2.3113
Hyd. No. 12 -- 25 Year
Q (cfs)
120.00
100.00
80.00
40.00
0.00
120 240 360 480 600 720 840 960 1080 1200
Hyd No 12 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 13
Post DA 2.3C
100
Sunday, 03 / 7 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 4.293 cfs
Storm frequency
= 25 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 8,705 cuft
Drainage area
= 0.510 ac
Curve number
= 67
Basin Slope
= 0.0 %
Hydraulic length
= Oft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 9.06 in
Distribution
= Type ll
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
4.00
3.00
l
j 2.00
1.00
Post DA 2.3C
Hyd. No. 13 -- 25 Year
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 13 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
101
Sunday, 03 / 7 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 8.615 cfs
Storm frequency
= 25 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 33,237 cuft
Drainage area
= 2.020 ac
Curve number
= 62*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 12.30 min
Total precip.
= 9.06 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
Q (cfs)
10.00 -
8.00
6.00
4.00
2.00
Post DA 2.4
Hyd. No. 14 -- 25 Year
Q (cfs)
10.00
8.00
M
4.00
2.00
0.00 -I 1 1 1 1 - I i i i 1- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14 Time (min)

Hydrograph
Report
102
Hydrallow Hydrographs Extension for AutodeskV Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 0317 J 2MI
Hyd, No. 16
DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
= 9.034 cfs
Storm frequency
= 25 yrs
Time to peak
= 744 min
Time interval
= 2 min
Hyd. volume
= 102,030 tuft
Inflow hyd. No.
= 10 - Post DA 2.2
Max. Elevation
= 19.14 ft
Reservoir name
= Dry Pond -WEST
Max. Storage
= 43,686 cult
Storage Indication Tnethod used.
Q {cfs;
35.00
30.00
25.00
20.00
15.00
MCA
DRY POND - WEST
Hyd. No. 16 — 25 Year
I
Y
s
i
}
1
4
1
d
s
4
1
4
1
I � �
I
I
Q (cis)
35.00
30.00
25.00
t
15.00
10.00
5.00
0.00 -L— . ' 0.00
0 360 720 1080 1440 1800 2160 2520 2880 3240 3600
Time (min)
Hyd No. 16 Hyd No. 10 Total storage used = 43,686 cult

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
l Hyd. No. 17
Post Inflow to East Pond
103
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 119.75 cfs
Storm frequency
= 25 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 380,102 cuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
Post Inflow to East Pond
Hyd. No. 17 -- 25 Year
100.00
80.00
I 60.00
4
I
40.00
20.00
I
Q (Cfs)
120.00
100.00
40.00
20.00
0.00 1 1 1 i i L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 17 Hyd No. 11 Hyd No. 12 Time (min)

Hydrograph Report
1
104
Hydras = Hydrographs E4wsion
for Autodeskg Civil 3D@ 2019 by Autodesk. Inc. Y2019.2
Sunday. 03 / 7 / 2021
Hyd. No. 18
DRY POND - EAST
Hydrograph type
= Reservoir
Peak discharge
= 46.57 cls
Storm frequency
= 25 yrs
Time to peak
= 734 min
Time interval
= 2 min
Hyd. volume
= 380,097 cult
Inflow hyd. No.
= 17 - Post Inflow to East Pond
Max. Elevation
= 18.10 ft
Reservoir name
= Dry Pond -EAST
Max. Storage
= 140,880 cult
storage Indicabon inethod used.
DRY POND - EAST
Q (`s)
Hyd. No. 18 — 25 Year
Q (ds)
i 120.00
�
120.00
100.00
a
100.00
J I
80.00 -
'
1
i
80.00
`
� J{
V
{ 60.00
1
60.00
I
40.00
9
40.00
7
i
20.00
20.00
0.00 -
l
I
__ i._-
0.00
0
120
240
360
480
600 720 840
960
1080
1200
1320 1440
1560
i
Hyd
No. 18
—Hyd
No. 17
Total
storage
used=140,880 cult
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Hyd. No. 20
Post-Dev Outlet B (Detained)
105
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 16.97 cfs
Storm frequency
= 25 yrs
Time to peak
= 730 min
Time interval
= 2 min
Hyd. volume
= 135,267 cult
Inflow hyds.
= 14, 16
Contrib. drain. area
= 2.020 ac
Q (cfs)
' 18.00 -
15.00
12.00
9.00
6.00
3.00
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 25 Year
Q (cfs)
18.00
15.00
12.00
9.00
6.00
3.00
0.00 1 1 1 ' -- — ...� i I I- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 20 Hyd No. 14 Hyd No. 16 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 21
Post-Dev Outlet C (Detained)
Hydrograph type = Combine
Peak discharge
Storm frequency = 25 yrs
Time to peak
Time interval = 2 min
Hyd. volume
Inflow hyds. = 13, 18
Contrib. drain. area
40.00
30.00
20.00
10.00
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 25 Year
120 240 360 480 600
Hyd No. 21 Hyd No. 13
106
Sunday, 03 / 7 / 2021
= 47.12 cfs
= 734 min
= 388,803 cuft
= 0.510 ac
Q (cfs)
50.00
40.00
30.00
20.00
10.00
0.00
720 840 960 1080 1200 1320 1440 1560
, Hyd No. 18 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 22
Post Out Total (Detained)
107
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 70.29 cfs
Storm frequency
= 25 yrs
Time to peak
= 732 min
Time interval
= 2 min
Hyd. volume
= 553,869 tuft
Inflow hyds.
= 9, 20, 21
Contrib. drain. area
= 2.040 ac
Q (cfs
80.00 - 80.00
70.00 70.00
60.00 - 60.00
50.00 — 50.00
40.00 - 40.00
30.00 30.00
20.00 20.00
{
i
10.00 10.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 22 Hyd No. 9 - Hyd No. 20 Hyd No. 21 Time (min)
Post Out Total (Detained)
Hyd. No. 22 -- 25 Year

108
jI
L
Hydrograph Summary Report
ydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(tuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(tuft)
Hydrograph
Description
1
SCS Runoff
14.66
2
734
66,558
-----
-
Pre DA 1.1 (Outlet A)
2
SCS Runoff
20.75
2
724
63,638
--- ------
-----
Pre DA 1.2
3
SCS Runoff
84.64
2
728
325,029
----- ---
------
Pre DA 1.3 (Outlet C)
4
SCS Runoff
9.856
2
728
37,896
---- ------
------
Pre DA 1.4
6
Combine
28.88
2
724
101,534
2, 4, ----
------
Pre-Dev Outlet B
7
Combine
122.66
2
728
493,120
1, ' ------
----
Pre-Dev TOTAL OUT
9
SCS Runoff
8.920
2
734
39,477
-----
----
Post DA 2.1 (Outlet A)
10
SCS Runoff
41.72
2
724
127,547
----
-----
Past DA 2.2
11
SCS Runoff
53.97
2
728
208,139
----
------
Post DA 2.3A
12
SCS Runoff
124.71
2
716
266,522
--
----
Post DA 2.313
13
SCS Runoff
5.480
2
716
11,189
---
------
Post DA 2.3C
14
SCS Runoff
11.34
'
728
43,500
---
----
Post DA 2.4
16
Reservoir
15.16
2
738
127,545
10 19.52
51,171
DRY POND - WEST
17
Combine
147.41
2
716
474,661
11, 12, ----
-----
Post Inflow to East Pond
18
Reservoir
64.45
'
732
474,656
17 18.56
166,868
DRY POND - EAST
20
Combine
24.39
2
732
171,046
14, 16,
Post-Dev Outlet B (Detained)
21
Combine
65.16
2
732
485,845
13, 18,
-----
Past-Dev Outlet C (Detained)
22
Combine
98.41
732
696,368
9, 20, 21
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 50 Year
Sunday, 03 17 12021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) _ [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
Q (cfs)
15.00
12.00
9.00
6.00
3.00
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 50 Year
109
Sunday, 03 / 7 / 2021
= 14.66 cfs
= 734 min
= 66,558 cuft
= 50*
= Oft
= 17.50 min
= Type III
= 484
Q (cfs)
15.00
12.00
M
. 11
3.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report 110
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
= 20.75 cfs
Storm frequency
= 50 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 63,638 cuft
Drainage area
= 4.620 ac
Curve number
= 50*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 6.40 min
Total precip.
= 10.70 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
` Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74)] / 4.620
Q (cfs)
21
18.00
15.00
12.00
WE
6.00
3.00
Pre DA 1.2
Hyd. No. 2 -- 50 Year
Q (cfs)
21.00
18.00
15.00
12.00
9.00
6.00
3.00
0.00 -' 1 1 1 I I I I -_ i I i
L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
111
Sunday, 03 / 7 / 2021
Hydrograph type
= SCS Runoff
Peak discharge
= 84.64 cfs
Storm frequency
= 50 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 325,029 cuft
Drainage area
= 15.470 ac
Curve number
= 61 *
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= TR55
Time of conc. (Tc)
= 12.90 min
Total precip.
= 10.70 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
' Composite (Area/CN) = [(1.840 x 98) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 61)] / 15.470
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 50 Year
80.00
70.00
60.00
50.00
40.00
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 - I
- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 31W2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 1.850 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Q (cfs)
10.00
M
. 1X
4.00
2.00
Pre DA 1.4
Hyd. No. 4 -- 50 Year
112
Sunday, 03 17 / 2021
= 9.856 cfs
= 728 min
= 37,896 cuft
= 60*
= Oft
= 12.30 min
= Type III
= 484
Q (Cfs)
10.00
KI
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 6
Pre-Dev Outlet B
113
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 28.88 cfs
Storm frequency
= 50 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 101,534 cuft
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
25.00
20.00
15.00
10.00
5.00
t
' 0.00
0
Pre-Dev Outlet B
Hyd. No. 6 -- 50 Year
Q (cfs)
30.00
25.00
20.00
15.00
10.00
5.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 Hyd No. 2 Hyd No. 4

Hydrograph
Report
114
Hydraflow Hydrographs Extension
for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type
= Combine
Peak discharge
= 122.66 cfs
Storm frequency
= 50 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 493,120 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
120.00
100.00
80.00
60.00
40.00
20.00
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 60 Year
Q (cfs)
140.00
120.00
100.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 Hyd No. 3 Hyd No. 6

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.040 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.690 x 98) + (1.350 x 39)] / 2.040
Q (cfs)
10.00 —
8.00
6.00
4.00
2.00
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 50 Year
115
Sunday, 03 17 / 2021
= 8.920 cfs
= 734 min
= 39,477 tuft
= 59*
= 0 ft
= 16.70 min
= Type III
= 484
Q (cfs)
10.00
8.00
Ace
4.00
WC
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 9 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.890 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
Q (cfs)
50.00
30.00
20.00
10.00
Post DA 2.2
Hyd. No. 10 -- 50 Year
120 240 360 480 600 720 840
Hyd No. 10
116
Sunday, 03 / 7 / 2021
= 41.72 cfs
= 724 min
= 127,547 cuft
= 76*
= Oft
= 5.00 min
= Type III
= 484
Q (cfs)
50.00
40.00
20.00
10.00
0.00
960 1080 1200 1320 1440
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.800 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
' Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] / 7.800
Q (cfs)
50.00
40.00
30.00
20.00
10.00
Post DA 2.3A
Hyd. No. 11 -- 50 Year
117
Sunday, 03 / 7 12021
= 53.97 cfs
= 728 min
= 208,139 tuft
= 72*
= Oft
= 12.90 min
= Type III
= 484
Q (cfs)
60.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11 Time (min)

Hydrograph Report 118
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 0317 12021
Hyd. No. 12
Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
= 124.71 cfs
Storm frequency
= 50 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 266,522 cuft
Drainage area
= 9.560 ac
Curve number
= 80
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 10.70 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
120.00
100.00
80.00
60.00
40.00
20.00
Post DA 2.31B
Hyd. No. 12 -- 50 Year
Q (cfs)
140.00
120.00
100.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200
Hyd No. 12
Time (min)

Hydrograph
Report
119
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
= 5.480 cfs
Storm frequency
= 50 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 11,189 cuft
Drainage area
= 0.510 ac
Curve number
= 67
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 10.70 in
Distribution
= Type II
l
l Storm duration
= 24 hrs
Shape factor
= 484
5.00
4.00
3.00
2.00
1.00
0.00
0
Post DA 2.3C
Hyd. No. 13 -- 50 Year
120 240 360 480 600 720 840
Hyd No. 13
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.020 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 10.70 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
Q (cfs)
12.00 —
10.00
6.00
4.00
2.00
Post DA 2.4
Hyd. No. 14 -- 50 Year
120
Sunday, 03 / 7 / 2021
= 11.34 cfs
= 728 min
= 43,500 tuft
= 62*
= 0 ft
= 12.30 min
= Type III
= 484
Q (cfs)
12.00
10.00
w
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14
Time (min)

Hydrograph Report
Hydmllio r WWmWaphs Extension
for Autode" cirri 3D& 2019 by Autodesk. Inc. M192
Hyd. No. 1 G
DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 10 - Post DA 2.2
Max. Elevation
Reservoir name
= Dry Pond -WEST
Max. Storage
Storage lndicafaon method used.
DRY POND - WEST
Hyd. No. 16 — 50 Year
40.00
30.00
20.00
10.00
121
Sunday, 031712021
= 15.16 cfs
= 738 min
= 127,545 c uft
_ 19.52 ft
= 51,171 cuft
Q (ds)
50.00
40.00
d t�
20.00
10.00
0.00 1 1 1 -- - . i_ O.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 16 Hyd No. 10 Total storage used = 51,171 cult Time (min)

Hydrograph
Report
122
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
= 147.41 cfs
Storm frequency
= 50 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 474,661 cuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
Post Inflow to East Pond
Hyd. No. 17 -- 50 Year
140.00
120.00
100.00
80.00
.M
40.00
20.00
Q (cfs)
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00 -I --r - - - I i- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 17 Hyd No. 11 Hyd No. 12 Time (min)

Hydrograph Report 123
Hydraflow Hydrographs Extension for AutodeskV OW 3D@ 2019 by Autodesk, Inc, v2019.2
DRY POND - EAST
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 50 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 17 - Post Inflow to East Pond
Max. Elevation
Reservoir name
= Dry Pond - EAST
Max. Storage
Storage Indication rnedW used.
DRY POND - EAST
Sunday, 031712021
= 64.45 cfs
= 732 mitt
= 474,656 cult
= 18.56 ft
= 166,868 cult
Q (cfs)
Hyd. No. 18 -- 50 Year
Q (cfs)
160.00
160.00
a
140.00
,
140.00
120.00
120.00
i
j J
--....-.—
__
1
100.00
100.00
80.00
80.00
60.00
I
�,
60.00
i
40.00
I
40.00
�
l
t
20.00
20.00
0.00 -
i
- 0.00
L 0
120 240
360 480 600 720 840 960 1080 1200 1320 1440
1560
Time (min)
Hyd No. 18
Hyd No. 17 Total storage used=166,868 cuff

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Hyd. No. 20
Post-Dev Outlet B (Detained)
124
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 24.39 cfs
Storm frequency
= 50 yrs
Time to peak
= 732 min
Time interval
= 2 min
Hyd. volume
= 171,046 cuft
Inflow hyds.
= 14, 16
Contrib. drain. area
= 2.020 ac
24.00
20.00
16.00
12.00
8.00
4.00
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 50 Year
Q (cfs)
28.00
24.00
20.00
16.00
12.00
8.00
4.00
- 0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 20 Hyd No. 14 Hyd No. 16 Time (min)

Hydrograph Report 125
Hydraflow Hydrographs Extension for Autodesk® Civil 3139) 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 21
Post-Dev Outlet C (Detained)
Hydrograph type = Combine Peak discharge = 65.16 cfs
Storm frequency = 50 yrs Time to peak = 732 min
Time interval = 2 min Hyd. volume = 485,845 cuft
Inflow hyds. = 13, 18 Contrib. drain. area = 0.510 ac
60.00
50.00
40.00
30.00
20.00
10.00
0.00
0
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 50 Year
Q (cfs)
70.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 21 Hyd No. 13 Hyd No. 18 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 22
Post Out Total (Detained)
Hydrograph type = Combine
Peak discharge
Storm frequency = 50 yrs
Time to peak
Time interval = 2 min
Hyd. volume
Inflow hyds. = 9, 20, 21
Contrib. drain. area
60.00
40.00
20.00
Post Out Total (Detained)
Hyd. No. 22 -- 50 Year
120 240 360 480 600 720 840
Hyd No. 22 Hyd No. 9
126
Sunday, 03 / 7 / 2021
= 98.41 cfs
= 732 min
= 696,368 cuft
= 2.040 ac
Q (cfs)
100.00
60.00
40.00
20.00
0.00
960 1080 1200 1320 1440 1560
Hyd No. 20 Hyd No. 21 Time (min)

127
Hydrograph Summary Report
ydraflow Hydrographs Extension for Autodesk0 Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
20.07
2
734
89,691
----
------
Pre DA 1.1 (Outlet A)
2
SCS Runoff
28.40
2
724
85,756
-----
-----
Pre DA 1.2
3
SCS Runoff
109.34
2
728
419,006
-----
------
Pre DA 1.3 (Outlet C)
4
SCS Runoff
12.79
2
728
49,020
---
------
---
Pre DA 1.4
6
Combine
39.04
2
724
134,776
2, 4,
------
-----
Pre-Dev Outlet B
7
Combine
160.65
2
728
643,472
' '
----
Pre-Dev TOTAL OUT
9
SCS Runoff
11.60
2
734
51,246
--
Post DA 2.1 (Outlet A)
10
SCS Runoff
51.02
2
724
157,590
------
Post DA 2.2
11
SCS Runoff
66.91
2
728
269,751
---
Post DA 2.3A
12
SCS Runoff
150.72
2
716
326,252
--
----
Post DA 2.313
13
SCS Runoff
6.871
2
716
14,156
--•
-----
Post DA 2.3C
14
SCS Runoff
14.58
7
728
55,891
-
--
—
Post DA 2.4
16
Reservoir
5.57
2
32
157,588
10
19.80
56,436
DRY POND - WEST
17
Combine
79.43
2
16
586,003
11, 12,
--
Post Inflow to East Pond
18
Reservoir
19.84
r24
585,998
17
1f
185,415
DRY POND- EAST
20
Combine
39.90
2
730
213,479
14, 16,
--
------
Post-Dev Outlet B (Detained)
21
Combine
101.69
2
724
600,154
- 13, 18,
--
Post-Dev Outlet C (Detained)
22
Combine
144.99
730
864,879
9, 20, 21
---
Post Out Total (Detained)
37630.054 - Hydraflow - 2021.03.04.gpw
Return Period: 100 Year
Sunday, 03 / 7 / 2021

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 1
Pre DA 1.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.530 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
Composite (Area/CN) _ [(0.700 x 98) + (0.010 x 55) + (3.470 x 39) + (0.350 x 61)] / 4.530
Q (cfs)
21.00 —
18.00
15.00
12.00
9.00
. ��
3.00
Pre DA 1.1 (Outlet A)
Hyd. No. 1 -- 100 Year
128
Sunday, 03 / 7 / 2021
= 20.07 cfs
= 734 min
= 89,691 cuft
= 50*
= 0 ft
= 17.50 min
= Type III
= 484
Q (cfs)
21.00
18.00
15.00
12.00
M
6.00
3.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Pre DA 1.2
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 4.620 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.680 x 30) + (3.200 x 55) + (0.140 x 70) + (0.470 x 39) + (0.100 x 61) + (0.030 x 74)] / 4.620
25.00
20:00
15.00
10.00
5.00
0.00
0
Pre DA 1.2
Hyd. No. 2 -- 100 Year
129
Sunday, 03 / 7 / 2021
= 28.40 cfs
= 724 min
= 85,756 cuft
= 50*
= Oft
= 6.40 min
= Type III
= 484
Q (cfs)
30.00
25.00
20.00
15.00
10.00
4 YX
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 3
Pre DA 1.3 (Outlet C)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 15.470 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
*Composite (Area/CN) [(1.B40 x 9B) + (5.710 x 55) + (0.260 x 70) + (1.740 x 39) + (5.920 x 61)] / 15.470
100.00
60.00
40.00
20.00
130
Sunday, 03 / 7 / 2021
= 109.34 cfs
= 728 min
= 419,006 cuft
= 61*
= 0 ft
= 12.90 min
= Type III
= 484
Pre DA 1.3 (Outlet C)
Hyd. No. 3 -- 100 Year
Q (Cfs)
120.00
100.00
60.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 4
Pre DA 1.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 1.850 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(0.020 x 30) + (0.060 x 55) + (0.240 x 39) + (1.360 x 61) + (0.090 x 74) + (0.080 x 98)] / 1.850
Q (cfs)
14.00
12.00
10.00
6.00
4.00
2.00
Pre DA 1.4
Hyd. No. 4 -- 100 Year
131
Sunday, 03 / 7 / 2021
= 12.79 cfs
= 728 min
= 49,020 cuft
= 60*
= 0 ft
= 12.30 min
= Type III
= 484
Q (cfs)
14.00
12.00
10.00
M
* KI
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 6
Pre-Dev Outlet B
132
Sunday, 03 / 7 / 2021
Hydrograph type
=Combine
Peak discharge
= 39.04 cfs
Storm frequency
= 100 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 134,776 cult
Inflow hyds.
= 2, 4
Contrib. drain. area
= 6.470 ac
Q (cfs)
40.00
30.00
20.00
10.00
Pre-Dev Outlet B
Hyd. No. 6 -- 100 Year
120 240 360 480 600 720 840
Hyd No. 6 Hyd No.
Q (cfs)
40.00
30.00
20.00
10.00
- 0.00
960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph
Report
133
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 7
Pre-Dev TOTAL OUT
Hydrograph type
= Combine
Peak discharge
= 160.65 cfs
Storm frequency
= 100 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 643,472 cuft
Inflow hyds.
= 1, 3, 6
Contrib. drain. area
= 20.000 ac
Q (cfs)
180.00
160.00
140.00
120.00
100.00
80.00
Pre-Dev TOTAL OUT
Hyd. No. 7 -- 100 Year
Q (cfs)
180.00
160.00
140.00
120.00
100.00
80.00
60.00 60.00
40.00 40.00
I
20.00 ; 20.00
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 7 Hyd No. 1 � Hyd No. 3 Hyd No. 6

Hydrograph Report
Hydreflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 9
Post DA 2.1 (Outlet A)
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.040 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
'Composite (Area/CN) _ [(0.690 x 98) + (1.350 x 39)] / 2.040
Q (cfs)
12.00
10.00
8.00
.M
4.00
2.00
0.00
0
Post DA 2.1 (Outlet A)
Hyd. No. 9 -- 100 Year
134
Sunday, 03 / 7 / 2021
= 11.60 cfs
= 734 min
= 51,246 tuft
= 59*
= 0 ft
= 16.70 min
= Type III
= 484
Q (cfs)
12.00
10.00
8.00
6.00
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 9
Time (min)

Hydrograph
Report
135
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 10
Post DA 2.2
Hydrograph type
= SCS Runoff
Peak discharge
= 51.02 cfs
Storm frequency
= 100 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 157,590 cuft
Drainage area
= 4.890 ac
Curve number
= 76*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 12.60 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
* Composite (Area/CN) = [(1.600 x 98) + (1.280 x 39) + (0.580 x 61) + (0.060 x 74)] / 4.890
50.00
40.00
30.00
20.00
10.00
we
Post DA 2.2
Hyd. No. 10 -- 100 Year
Q (cfs)
60.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 10 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2019.2
Hyd. No. 11
Post DA 2.3A
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 7.800 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= User
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shape factor
* Composite (Area/CN) = [(3.350 x 98) + (1.800 x 39) + (2.650 x 61)] 17.800
60.00
50.00
40.00
30.00
20.00
10.00
136
Sunday, 03 / 7 / 2021
= 66.91 cfs
= 728 min
= 259,751 cuft
= 72*
= Oft
= 12.90 min
= Type III
= 484
Post DA 2.3A
Hyd. No. 11 -- 100 Year
Q (cfs)
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 11 Time (min)

Hydrograph Report 137
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 / 2021
Hyd. No. 12
Post DA 2.3B
Hydrograph type
= SCS Runoff
Peak discharge
= 150.72 cfs
Storm frequency
= 100 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 326,252 cuft
Drainage area
= 9.560 ac
Curve number
= 80
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 12.60 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
0
Post DA 2.31B
Hyd. No. 12 -- 100 Year Q (cfs)
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200
Hyd No. 12
Time (min)

Hydrograph Report 138
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Sunday, 0317 / 2021
Hyd. No. 13
Post DA 2.3C
Hydrograph type
= SCS Runoff
Peak discharge
= 6.871 cfs
Storm frequency
= 100 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 14,156 cuft
Drainage area
= 0.510 ac
Curve number
= 67
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 12.60 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post DA 2.3C
Q (cfs) Hyd. No. 13 -- 100 Year Q (Cfs)
7.00 7.00
6.00 6.00
5.00 5.00
4.00 4.00
3.00 3.00
2.00 - - 2.00
1.00 1.00
0.00 - — 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 13 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2
Hyd. No. 14
Post DA 2.4
Hydrograph type
= SCS Runoff
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Drainage area
= 2.020 ac
Curve number
Basin Slope
= 0.0 %
Hydraulic length
Tc method
= TR55
Time of conc. (Tc)
Total precip.
= 12.60 in
Distribution
Storm duration
= 24 hrs
Shaoe factor
* Composite (Area/CN) = [(0.170 x 98) + (0.270 x 39) + (1.420 x 61) + (0.160 x 74)] / 2.020
Q (cfs)
15.00 —
12.00
• 11
6.00
3.00
0.00
0
Post DA 2.4
Hyd. No. 14 -- 100 Year
139
Sunday, 03 / 7 / 2021
= 14.58 cfs
= 728 min
= 55,891 cuft
= 62*
= Oft
= 12.30 min
= Type III
= 484
Q (cfs)
15.00
12.00
M
M
3.00
0.-no
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 14
Time (min)

Hydrograph Report
Hydra#1ow Hydrographs Extension for AuiodesW Civil 3D@ 2019 by Autodesk, Inc. v2019.2
Hyd. No. 16
DRY POND - WEST
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 10 -Post DA 2.2
Max. Elevation
Reservoir name
= Dry Pond -WEST
Max. Storage
Skorage Indication meUmd used.
0 (cfs
60.00
40.00
30.00
20.00
10.00
DRY POND - WEST
Hyd. No. 16 —100 Year
140
Sunday. 03 J 712021
= 25.57 cfs
= 732 min
= 157,588 cult
= 19.80 ft
= 56,436 cult
i
I
i
d
lilt
.... ..:..........
.. ,
..
0 (+CPS)
60.00
50.00
i $A
20.00
10.00
0.00 - I i _
- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 16 -- Hyd No. 10 Total storage used = 56,436 CA

Hydrograph
Report
141
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 17
Post Inflow to East Pond
Hydrograph type
= Combine
Peak discharge
= 179.43 cfs
Storm frequency
= 100 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 586,003 tuft
Inflow hyds.
= 11, 12
Contrib. drain. area
= 17.360 ac
Q (cfs)
150.00
120.00
90.00
60.00
30.00
Post Inflow to East Pond
Hyd. No. 17 — 100 Year
Q (cfs)
180.00
150.00
120.00
90.00
60.00
30.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd Na. 17 Hyd No. 11 Hyd No. 12 Time (min)

e Hydrograph Report 142
Hydraflow Hydrographs Extension for Autodesk@) civil 3131D 2019 by Autodesk, Inc, v2019.2 Sunday, 031712021
Hyd. No. 18
f
DRY POND - EAST
Hydrograph type = Reservoir Peak discharge = 99.84 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 585,998 cult
Inflow hyd. No. = 17 - Post Inflow to East Pond Max. Elevation = 18.89 ft
Reservoir name = Dry Pond - EAST Max. Storage = 185,415 cuff
Storage Indication meftaod used.
i
1
DRY POND - EAST
Q (ds) Q (ds)
' Hyd- No. 18 —100 Year
180.00 180.00
j
I 1 I 1 1
1
150.00
150.00
120.00 120.00
90.00 j' 90.00
1 x
a � i
a
60.00 60.00
i
I
30.00 +— — 30.00
1
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
- Hyd No. 18 Hyd No. 17 Total storage used = 185,415 cult

Hydrograph Report 143
Hydraflow Hydrographs Extension for Autodesk® Civil 3130 2019 by Autodesk, Inc. v2019.2 Sunday, 03 17 / 2021
Hyd. No. 20
Post-Dev Outlet B (Detained)
Hydrograph type = Combine Peak discharge = 39.90 cfs
Storm frequency = 100 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 213,479 cuft
Inflow hyds. = 14, 16 Contrib. drain. area = 2.020 ac
Q (cfs)
30.00
20.00
10.00
Post-Dev Outlet B (Detained)
Hyd. No. 20 -- 100 Year
Q (cfs)
40.00
30.00
20.00
10.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 20 Hyd No. 14 Hyd No. 16 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 21
Post-Dev Outlet C (Detained)
144
Sunday, 03 / 7 / 2021
Hydrograph type
= Combine
Peak discharge
= 101.69 cfs
Storm frequency
= 100 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 600,154 cuft
Inflow hyds.
= 13, 18
Contrib. drain. area
= 0.510 ac
f
Q (cfs)
120.00
100.00
80.00
60.00
40.00
20.00
0.00
0
Post-Dev Outlet C (Detained)
Hyd. No. 21 -- 100 Year
Q (cfs)
120.00
100.00
80.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 21 -Hyd No. 13 Hyd No. 18 Time (min)

Hydrograph Report
145
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Sunday, 03 / 7 / 2021
Hyd. No. 22
Post Out Total (Detained)
Hydrograph type = Combine
Peak discharge
= 144.99 cfs
Storm frequency = 100 yrs
Time to peak
= 730 min
Time interval = 2 min
Hyd. volume
= 864,879 cuft
Inflow hyds. = 9, 20, 21
Contrib. drain. area
= 2.040 ac
140.00
120.00
100.00
80.00
60.00
40.00
Post Out Total (Detained)
Hyd. No. 22 -- 100 Year
Q (cfs)
160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 22 Hyd No. 9 - Hyd No. 20 Hyd No. 21 Time (min)

Hydraflow Rainfall Report
146
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Sunday, 03 / 7 12021
Return
Period
Intensity -Duration -Frequency Equation Coefficients (FHA)
(Yrs)
B
D
E
(NIA)
1
76.3783
12.3000
0.8781
-----
2
93.3058
12.8000
0.8794
--
3
0.0000
0.0000
0.0000
--------
5
0.0000
0.0000
0.0000
----
10
98.4973
12.6000
0.8087
---
25
82.9919
10.7000
0.7342
-----
50
78.7190
10.1000
0.6964
-
100
71.4527
8.9000
0.6506
----
File name: WILMINGTON IDF 2020-08-24 SJB.IDF
Intensity = B / (Tc + D)"E
Return
Period
Intensity Values (in/hr)
(Yrs)
5 min
10
15
20
25
30
35
40
45
50
55
60
1
6.25
5.00
4.19
3.61
3.18
2.85
2.58
2.37
2.18
2.03
1.90
1.78
2
7.42
5.97
5.01
4.33
3.83
3.43
3.11
2.85
2.63
2.45
2.29
2.15
3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
10
9.69
7.91
6.73
5.88
5.24
4.74
4.33
4.00
3.71
3.47
3.26
3.08
25
10A9
8.97
7.65
6.72
6.01
5.46
5.01
4:65
4.34
4.07
3.84
3.64
50
11.89
9.74
8.34
7.35
6.61
6.02
5.55
5.16
4.82
4.54
4.30
4.08
100
12.89
10.56
9.06
8.01
7.22
6.60
6.10
5.69
5.34
5.04
4.78
4.55
Tc = time in minutes. Values may exceed 60.
PreciD. file name: R:1332141352-Durham Marrintt1nn1-339-rlurh=m iw=rri. ff%r1n1Acrm%errni n �;-%r%110UARA ___
Storm
Distribution
Rainfall Precipitation Table (in)
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
SCS 24--hour
3.83
4.64
0.00
6.01
7.21
9.06
10.70
12.60
SCS 6-Hr
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff -1st
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-2nd
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-3rd
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-4th
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-Indy
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Custom
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

Hydraflow Table of Contents
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
37630.054 - Hydraflow - 2021.03.04.gpw
Sunday, 03 17 / 2021
Watershed Model Schematic...................................................................................... 1
HydrographReturn Period Recap............................................................................. 2
1 -Year
SummaryReport ......................................................................................................................... 3
HydrographReports................................................................................................................... 4
Hydrograph No. 1, SCS Runoff, Pre DA 1.1 (Outlet A�...........................................................
4
TR-55 Tc Worksheet...........................................................................................................
5
Hydrograph No. 2, SCS Runoff, Pre DA 1.2.............................................................................
6
TR-55 Tc Worksheet...........................................................................................................
7
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)............................................................
8
TR-55 Tc Worksheet...........................................................................................................
9
Hydrograph No. 4, SCS Runoff, Pre DA 1.4...........................................................................
10
TR-55 Tc Worksheet.........................................................................................................
11
Hydrograph No. 6, Combine, Pre-Dev Outlet B.....................................................................
12
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT...............................................................
13
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A) ........................................................
14
TR-55 Tc Worksheet.........................................................................................................
15
Hydrograph No. 10, SCS Runoff, Post DA 2.2.......................................................................
16
Hydrograph No. 11, SCS Runoff, Post DA 2.3A....................................................................
17
Hydrograph No. 12, SCS Runoff, Post DA 2.313 .....................................................................
18
Hydrograph No. 13, SCS Runoff, Post DA 2.3C....................................................................
19
Hydrograph No. 14, SCS Runoff, Post DA 2.4.......................................................................
20
TR-55 Tc Worksheet.........................................................................................................
21
Hydrograph No. 16, Reservoir, DRY POND - WEST.............................................................
22
PondReport - Dry Pond - WEST......................................................................................
23
Hydrograph No. 17, Combine, Post Inflow to East Pond .......................................................
25
Hydrograph No. 18, Reservoir, DRY POND - EAST ............................ :................................
26.
PondReport - Dry Pond - EAST........................................................................................
27
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ................................................
29
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ................................................
30
Hydrograph No. 22, Combine, Post Out Total (Detained.....................................................
31
2 - Year
SummaryReport.......................................................................................................................
32
HydrographReports.................................................................................................................
Hydrograph No. 1, SCS Runoff, Pre DA 1.1 (Outlet A) .........................................................
33
33
Hydrograph No. 2, SCS Runoff, Pre DA 1.2...........................................................................
34
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)..........................................................
35
Hydrograph No. 4, SCS Runoff, Pre DA 1.4...........................................................................
36
Hydrograph No. 6, Combine, Pre-Dev Outlet B.....................................................................
37
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT...............................................................
38
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A) ........................................................
39
Hydrograph No. 10, SCS Runoff, Post DA 2.2.......................................................................
40
Hydrograph No. 11, SCS Runoff, Post DA 2.3A....................................................................
41
Hydrograph No. 12, SCS Runoff, Post DA 2.313 .....................................................................
42
Hydrograph No. 13, SCS Runoff, Post DA 2.3C....................................................................
43

Contents continued...
37630.054 - Hydraflow - 2021.03.04.gpw
Hydrograph No. 14, SCS Runoff, Post DA 2.4.......................................................................
44
f Hydrograph No. 16, Reservoir, DRY POND - WEST.............................................................
45
I Hydrograph No. 17, Combine, Post Inflow to East Pond .......................................................
46
Hydrograph No. 18, Reservoir, DRY POND - EAST..............................................................
47
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ................................................
48
f Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ................................................
49
Hydrograph No. 22, Combine, Post Out Total (Detained.....................................................
50
5 - Year
SummaryReport .......................................................................................................................
51
HydrographReports.................................................................................................................
Hydrograph No. 1, SCS Runoff, Pre DA 1.1(Outlet A) .........................................................
52
52
Hydrograph No. 2, SCS Runoff, Pre DA 1.2...........................................................................
53
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)..........................................................
54
Hydrograph No. 4, SCS Runoff, Pre DA 1.4...........................................................................
55
Hydrograph No. 6, Combine, Pre-Dev Outlet B.....................................................................
56
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT...............................................................
57
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet Al ........................................................
58
Hydrograph No. 10, SCS Runoff, Post DA 2.2.......................................................................
59
Hydrograph No. 11, SCS Runoff, Post DA 2.3A....................................................................
60
Hydrograph No. 12, SCS Runoff, Post DA 2.313 .....................................................................
61
Hydrograph No. 13, SCS Runoff, Post DA 2.3C....................................................................
62
Hydrograph No. 14, SCS Runoff, Post DA 2.4.......................................................................
63
Hydrograph No. 16, Reservoir, DRY POND - WEST.............................................................
64
Hydrograph No. 17, Combine, Post Inflow to East Pond .......................................................
65
Hydrograph No. 18, Reservoir, DRY POND - EAST.............................................................
66
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ................................................
67
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ................................................
68
Hydrograph No. 22, Combine, Post Out Total (Detained......................................................
69
10 -Year
SummaryReport.......................................................................................................................
70
HydrographReports.................................................................................................................
Hydrograph No. 1, SCS Runoff, Pre DA 1.1 (Outlet Al .........................................................
71
71
Hydrograph No. 2, SCS Runoff, Pre DA 1.2...........................................................................
72
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)..........................................................
73
Hydrograph No. 4, SCS Runoff, Pre DA 1.4...........................................................................
74
Hydrograph No. 6, Combine, Pre-Dev Outlet B.....................................................................
75
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT...............................................................
76
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A�........................................................
77
Hydrograph No. 10, SCS Runoff, Post DA 2.2.......................................................................
78
Hydrograph No. 11, SCS Runoff, Post DA 2.3A....................................................................
79
Hydrograph No. 12, SCS Runoff, Post DA 2.313 .....................................................................
80
Hydrograph No. 13, SCS Runoff, Post DA 2.3C....................................................................
81
Hydrograph No. 14, SCS Runoff, Post DA 2.4.......................................................................
82
Hydrograph No. 16, Reservoir, DRY POND - WEST............................................................
83
Hydrograph No. 17, Combine, Post Inflow to East Pond .......................................................
84
Hydrograph No. 18, Reservoir, DRY POND - EAST..............................................................
85
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ................................................
86
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ................................................
87

Contents continued...
37630.054 - Hydraflow - 2021.03.04.gpw
Hydrograph No. 22, Combine, Post Out Total (Detained ................................................. 88
25 - Year
SummaryReport .......................................................................................................................
89
HydrographReports................................................................................................................. 90
Hydrograph No. 1, SCS Runoff, Pre DA 1.1 (Outlet A) .........................................................
90
Hydrograph No. 2, SCS Runoff, Pre DA 1.2...........................................................................
91
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C).......................................................... 92
Hydrograph No. 4, SCS Runoff, Pre DA 1.4...........................................................................
93
Hydrograph No. 6, Combine, Pre-Dev Outlet B.....................................................................
94
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT...............................................................
95
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A) ........................................................
96
Hydrograph No. 10, SCS Runoff, Post DA 2.2.......................................................................
97
Hydrograph No. 11, SCS Runoff, Post DA 2.3A....................................................................
98
Hydrograph No. 12, SCS Runoff, Post DA 2.36.....................................................................
99
Hydrograph No. 13, SCS Runoff, Post DA 2.3C..................................................................
100
Hydrograph No. 14, SCS Runoff, Post DA 2.4.....................................................................
101
Hydrograph No. 16, Reservoir, DRY POND - WEST..........................................................
102
Hydrograph No. 17, Combine, Post Inflow to East Pond .....................................................
103
Hydrograph No. 18, Reservoir, DRY POND - EAST............................................................
104
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ..............................................
105
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ..............................................
106
Hydrograph No. 22, Combine, Post Out Total (Detained) ...................................................
107
50 - Year
SummaryReport .....................................................................................................................
108
HydrographReports...............................................................................................................
109
Hydrograph No. 1, SCS Runoff, Pre DA 1.1(OutletA�.......................................................
109
Hydrograph No. 2, SCS Runoff, Pre DA 1.2.........................................................................
110
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)........................................................
111
Hydrograph No. 4, SCS Runoff, Pre DA 1.4.........................................................................
112
Hydrograph No. 6, Combine, Pre-Dev Outlet B...................................................................
113
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT.............................................................
114
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A�......................................................
115
Hydrograph No. 10, SCS Runoff, Post DA 2.2.....................................................................
116
Hydrograph No. 11, SCS Runoff, Post DA 2.3A..................................................................
117
Hydrograph No. 12, SCS Runoff, Post DA 2.313 ...................................................................
118
Hydrograph No. 13, SCS Runoff, Post DA 2.3C..................................................................
119
Hydrograph No. 14, SCS Runoff, Post DA 2.4.....................................................................
120
Hydrograph No. 16, Reservoir, DRY POND - WEST..........................................................
121
Hydrograph No. 17, Combine, Post Inflow to East Pond .....................................................
122
Hydrograph No. 18, Reservoir, DRY POND - EAST...........................................................
123
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ..............................................
124
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ..............................................
125
Hydrograph No. 22, Combine, Post Out Total (Detained) ...................................................
126
100 -Year
jSummary Report ..................................................................................................................... 127
LHydrograph Reports............................................................................................................... 128
Hydrograph No. 1, SCS Runoff, Pre DA 1.1 (Outlet A�....................................................... 128

Contents continued...
37630.054 - Hydraflow - 2021.03.04.gpw
Hydrograph No. 2, SCS Runoff, Pre DA 1.2.........................................................................
129
Hydrograph No. 3, SCS Runoff, Pre DA 1.3 (Outlet C)........................................................
130
Hydrograph No. 4, SCS Runoff, Pre DA 1.4.........................................................................
131
Hydrograph No. 6, Combine, Pre-Dev Outlet B...................................................................
132
Hydrograph No. 7, Combine, Pre-Dev TOTAL OUT.............................................................
133
Hydrograph No. 9, SCS Runoff, Post DA 2.1 (Outlet A�......................................................
134
Hydrograph No. 10, SCS Runoff, Post DA 2.2.....................................................................
135
Hydrograph No. 11, SCS Runoff, Post DA 2.3A..................................................................
136
Hydrograph No. 12, SCS Runoff, Post DA 2.313 ...................................................................
137
Hydrograph No. 13, SCS Runoff, Post DA 2.3C..................................................................
138
Hydrograph No. 14, SCS Runoff, Post DA 2.4.....................................................................
139
Hydrograph No. 16, Reservoir, DRY POND - WEST..........................................................
140
Hydrograph No. 17, Combine, Post Inflow to East Pond .....................................................
141
Hydrograph No. 18, Reservoir, DRY POND - EAST............................................................
142
Hydrograph No. 20, Combine, Post-Dev Outlet B (Detained) ..............................................
143
Hydrograph No. 21, Combine, Post-Dev Outlet C (Detained) ..............................................
144
Hydrograph No. 22, Combine, Post Out Total(Detainedl...................................................
145
OFReport................................................................................................................ 146
L

WATER QUALITY CALCULATIONS

Project: Circle K - Wilmington Airport Project No.: 37630.054
Calculated By: JCD Date: 03/05/2021
Dry Extended Detention Basin Design
Area
Aria to
Offsite Impervious Area
0.00
Onsite Impervious Area
2.67
Total Impervious Are
2.67
Total Drainage Area To BMP
1 4.89
A_
2.A) Water Quality Runoff Volume Calculation (Required
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(I) Where: Rv = Runoff Coefficient, in/in
I I = Percent Impervious
1= 55%
j Rv = 0.541
Yttatra Ruutaf!`'1o(u► ".
Runoff volume, S= Desi n rainfall Rv (Drainage Area
Design Rainfall
inch
Drainage Area =
4.89 acres
Storage R utred = 1. 416 .cu. ft.
r
must nave Toreoay it storage required is over 10 acre -inches (36,300 c.f.)
i
Detention Volume Required 14,416 cu ft
25% Additonal Sed. Storage 18,020 cu ft
2.113) Water Quality Runoff Volume Calculation (Provided)
cantow
contow etevadon Area 'V61um 1.0Cfatrre. " 1b a , 2
ft .. cap it
14.50
0
0
0
0.00
15.00
238
60
60
0.50
16.00
4,173
2,206
2,265
1.50
17.00
12,673
8,423
10,688
2.50
8,419
20,107
3.20
18.00
15,040
4,392
24,499
3.50
18.75
17,302
12,128
36,627
4.25
19.25
18,515
8,954
45,581
4.75
20.00
20,792
14,740
60,321
5.50
20.75
23,021
16,430
76,751
6.25
- I . =u,',y ,a W-1 yuau,y aiovauun, iviaalmwn anuweu ueptn of ary pony = IU Tt
Provided Volume of Dry Basin 45,581 cu ft (to bottom of spillway)
3) Size Water Quality Orifice for (2-5) Day Drawdown for Runoff Volume
Q= CdA(2gh)T2 (Orifice Equation; Cd=0.60 & h=h/3; Pg 3-13 BMP Manual)
3.20
Water Quality Stage (ft)
1.50
Orfice Diameter (inches)
1.05
Driving Head (h/3) to Centroid of Orifice (ft)
0.06
Drawdown Rate (cfs)
20,107
Water Quality Volume (1(,o)
Vwo/(Q x 86,400)
Drawdown Time (days)
3.9
Drawdown Time (days) (2 - 5 days)
Bottom of Basin/Outlet
Orifice for Water Quality
Fop of Control Structure
Spillway Crest
fop of Basin
L

Project: Circle K -1
Calculated By: JCD
Dry Extended Detention Basin Design
f _ tous-
Offsite Impervious Area
0.00
Onsite Impervious Area
8.43
Total Impervious Area
8.43
Total Drainage Area To BMP
17.36
:t No.: 37630.054
Date: 03/05/2021
2.A) Water Quality Runoff Volume Calculation (Required
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) Where: Rv = Runoff Coefficient, in/in
I = Percent Impervious
1= 49%
Rv = 0.487
Runoff volume, S=(Desigin rainfall Rv (Drainage Area
Design Rainfall
inch
Drainage Area =1
17.36 acres
Stomge Required x
4f407 cu. ft.
' Must have forebay if storage required is over 10 acre -inches (36,300 c.f.)
Detention Volume Required 46,037 cu ft
25% Additonal Sed. Storage 57,547 cu ft
2.113) Water Quality Runoff Volume Calculation (Provided)
C IFrtavaito>4# Arad " fd�ttttne V,13 t 6 Sta Z
ft ft;. t9tft ft
13.25
0
0
0
0.00
14.00
1529
573
573
0.75
15.00
13,850
10,190
10,763
1.75
16.00
An 779
29,815
40,577
2.75
21,271
.61 848
3.25
17.00
47,595
22,975
84,822
3.75
18.00
53,426
50,511
135,333
4.75
18.50
56,235
27,415
162,748
5.25
20.00
65,401
91,227
253,975
6.75
Green shading is water quality elevation; Maximum allowed depth of dry pond = 10 ft
Provided Volume of Dry Basin 162,748 cu ft (to bottom of spillway)
3) Size Water Quality Orifice for (2-5) Day Drawdown for Runoff Volumi
Q = CdA(2gh)"
(Orifice Equation; Cd=0.60 & h=h/3; Pg 3-13 BMP Manual)
' 3.25
Water Quality Stage (ft)
` 3.00
Orfice Diameter (inches)
1.04
Driving Head (11/3) to Centroid of Orifice (ft)
0.24
Drawdown Rate (cfs)
61,848
Water Quality Volume (moo)
Vwo/(Q x 86,400)
Drawdown Time (days)
3.0
Drawdown Time (days) (2 - 5 days)
Bottom of Basin/Outlet
WQE
Top of Control Structure
Spillway Crest
Top of Basin

Pre Treatment Grass Swale - IIIA Circle K - Airport Blvd
TIMMOMS GROUP ■ -«t
Jacob Dooley 37630.054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) = 4.36 (Acres)
Coef. (C) = 0.77 (Dimensionless)
Inte. (1) = 0.75 (in/hr)
Flow (Q10) = 2.5 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.040 (Dimensionless) Ditch Length = 150 LF
Slope = 0.001 (ft/ft) Highest Elevation = 16.5
Z Required = 2.14 Ratio Lowest Elevation = 16.35
Side Slope (M) = :1
• - r A,_•." --
Flow Depth (Y) = •0.5o ft 6.0 in
Bottom Width (B) = 6.00 ft 72.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.03 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 1 0.45 i...
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18'7HK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
New A = 4.50 SF Hydraulic Residence Time
New P = 12.08 Wetted perimeter L=240V
New R = 0.37 Hydraulic radius V< 0.625
Z Actual = 2-33 Must be greater than z required=> 2.14 Okay
New V = 0.61 fps
HRT = 4.1 min
Liner: Grass #N/A LB/SF > 0.04 LB/SF #NIA
---------------------------------------------
Top Width = 18 ft
Min. Ditch Depth = 1 ft -------------
6 Flow Depth (Y) = 0.5 ft
1
Bottom Width (B) = 6 ft
Min. Ditch Depth ft Bottom Width ft Flow Depth (ft) , Top Width (ft) Side Slope
1.00 6.00 0,150 18 1 6:1
Ditch Liner
`RED IS USER INPUT
LATEST REVISION: 8/27/2020 4:03 PM

Pre Treatment Grass Swale - IIIB ' C
TIMMOMS GROW
Jacob Dooley +«.11c=_n NI oe'lc•4 atc- r a '.
Circle K - Airport Blvd
37630.054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) = 15.61 (Acres)
Coef. (C) = 0.75 (Dimensionless)
Inte. (1) = 0.75 (in/hr)
Flow (Q10) = 8.8 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.060 (Dimensionless) Ditch Length = 150 LF
Slope = 0.002 (ft/ft) Highest Elevation = 14.8
Z Required = 8.66 Ratio Lowest Elevation = 14.55
Side Slope (M) = :1
• ■
Flow Depth (Y) = 0.50 ft . , 6.0 in
Bottom Width (B) = 27.00 ft 324.0 in
Freeboard = 0.25 ft 3.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.05 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
Determine If Z Actual Is Greater Thar, Z Recuired - - - - ------------
New A = 14.75 SF Hydraulic Residence Time
New P = 32.10 Wetted perimeter L=240V
New R = 0.46 Hydraulic radius V- 0.625
Z Actual = 8.78 Must be greater than z required=> 8.66 Okay
New V = 0.60 fps
HRT = 4.1 min
Minimum E
Liner: North American Green, S75 1.55 LB/SF > 0-06 LB/SF Okay
F----------- ------------------------------- ---i
Top Width = 34.5 ft
Min. Ditch Depth = 0.75 \
r' Flow Depth (Y) = 0.5 It
i1
Bottom Width (B) = 27 ft
Min. Ditch Depth ft Bottom Width ft ; Flow Depth (ft) Top Width (ft) Side Slope
0,75 27-00 i 0.50 1 34-5 1 5.1
North American Green, S75 1 *RED IS USER INPUT
ii LATEST REVISION: 1/14/2021 10:34 AM
IL

:Ir f s . ■ gar '�
Pre Treatment Grass Swale - IIIB .2 YEAR" Circle KC Airport Blvd
Jacob Dooley .-.::ibis t 7--k q oft•N.,..at:;r._ 37630.654
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Area (A) = 15.61 (Acres)
Coef. (C) = CI-75 (Dimensionless)
Inte. (1) = 7.42 (inlhr)
Flow (Q10) = 86.9 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = (Dimensionless) Ditch Length = 150 LF
Slope = 0.002 (ft/ft) Highest Elevation = 14.8
Z Required = 85.69 Ratio Lowest Elevation = 14.55
Side Slope (M) _ :1
Flow Depth (Y) = 1-85 It 22.2 in
Bottom Width (B) = 27.00 it 324-0 in
Freeboard = 0.25 ft 3.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.19 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
--
Jute Net 0.45 c•. r_
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12" @22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
Determine
New A = 67.06 SF Hydraulic Residence Time
New P = 46.87 Wetted perimeter L=240V
New R = 1.46 Hydraulic radius V- 0.625
Z Actual = 86.40 Must be greater than z required=> 85.69 Okay
New V = 1.31 fps
HRT= 1.9 min
Minimum Desigeornetrj
n
North American Green, S75 1.55 LB/SF > 0.2 LB/SF Okay
F------------------- ---------------------------- i
N
Top Width = 48 ft
Min. Ditch Depth = 2.1
5 Flow Depth (Y) = 1.85 ft
1
Bottom Width (B) = 27 ft
j Min. Ditch Depth ft Bottom Wldth ft Flow Depth (ft) Top Width (ft) Side SI,
2-10 27.00 1,Ei5 48 5:1
North American Green, S75 "ED IS'
I
t-
LLATEST REVISION: 3/25/2021 10:25 AM

Pre Treatment Grass Swale - IIIB -10 YEA'R 0 % Circle K - Airport Blvd
TWIIIooleye TIMMONSGR©UPJacob
_,rr uos- 9 vu _ YIr•; ,y.. ., 37630.054
Drainage Ditch Design (Velocity Constraint)
tA
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0-03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Area (A) _- r 15.61 (Acres)
Coef. (C) = 0.75 (Dimensionless)
Inte. (1) = 9.70 (in/hr)
Flow (Q10) = 113.6 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.060 (Dimensionless) Ditch Length - 150 LF
Slope = 0.002 (ft/It) Highest Elevation = 14.8
Z Required = 112.02 Ratio Lowest Elevation = 14.55
Side Slope (M) = :1
Flow Depth (Y) = 2.15 ft - 25.8 in
Bottom Width (B) = 27.00 ft 324.0 in
Freeboard =_ _ 0.25 ft 3.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.22 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45 M _
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@1871-11K) 3.50 SC150 2.10
Class I (12" A22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
1�.:+i•: if,, ,'P• i l :`�''°i'-',f L. t.�r,.: � 1 icy -- _...
New A = 81.16 SF Hydraulic Residence Time
New P = 48.93 Wetted perimeter L=240V
New R = 1.66 Hydraulic radius V- 0.625
Z Actual = 113.76 Must be greater than z required=> 112-02 Okay
New V = 1.42 fps
HRT = 1.8 min
Liner: North American Green, S75 1.55 LB/SF > 0.23 LB/SF Okay
-----------------------------------------------
�N
Top Width = 51 ft
Min. Ditch Depth '= 2.4
\1,11 Flow Depth (Y) = 2.15 ft
Bottom Width (B) = 27 ft
Min. Ditch Depth ft Bottom Width ft Flow Depth ftTop Width ftSide Slope
2.40 27.00 2.15 51 1 5:1
s
North American Green, S75
*RED IS USER INPUT
LATEST REVISION: 3/25/2021 10:24 AM

Pre Treatment Graass Swale - IIIA - 2 YEAR, circle K -Airport Blvd
Jacob ' 1131yTajIMMdNs GaRkJuF' - • 37630054
_.
Drainage Ditch Design (Velocity Constraint)
l a
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
Area (A) = 4.36 (Acres)
Coef. (C) = 0.77 (Dimensionless)
Inte. (1) = 7.42 (in/hr)
Flow (Q10) = 24.9 (cfs)
Iuua,`rt ■
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = (Dimensionless) Ditch Length = 150 LF
Slope = 0.001 (ft/ft) Highest Elevation = 16.5
Z Required = 21.15 Ratio Lowest Elevation = 16.35
Side Slope (M) _ :1
Flow Depth (Y) = 1.50 It 18.0 in
Bottom Width (B)= 6.00 ft 72.0 in
Freeboard = 0.50 ft 6-0 in
.
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.09 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45 tr, a•..:
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"022"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
New A = 22.50 SF Hydraulic Residence Time
New P = 24.25 Wetted perimeter L=240V
New R = 0.93 Hydraulic radius V< 0.625
Z Actual = 21.40 Must be greater than z required=> 21.15 Okay
New V = 1.12 fps
HRT= _ 2.2'
tii lii•Ifi ii'1.� D-::; i"'• C. r'.NI
Liner: Grass #NIA LB/SF> 0 1 LB/SF #NIA
t------ --------- -------------------- ----------i
Top Width = 30 ft
Min. Ditch Depth = 2 ft _--___-_____�_____
B Flow Depth (Y) = 1.5 ft
�1
Bottom Width (B) = 6 ft
IIIIJINMAUQU
Min. Ditch Depth ft Bottom Width ft Flow De th ft Top Width ft Side Slope
2.00 6-00 1.50 30 1 6:1
_ Ditch Liner i
*RED IS USER INPUT
II LATEST REVISION: 3/25/2021 10:26 AM
L..

r / I y• a o% J;tfal"�
Pre Treatment Grass, � wale - IIIA -10 YEAR E Circle K - Airport Blvd
Jacob Dooley Tfl�'it+ ONS GROUP � E 3
_. as. I TL'e•la'lO :?" 37630.054
Drainage Ditch Design (Velocity Constraint)
trassed r YEAR
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Area (A) = 4-36 (Acres)
Coef. (C) = 0.77 (Dimensionless)
Inte. (1) = 9.70 (in/hr)
Flow (Q,a) = 32.6 (cfs)
211 -wom
a
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = (Dimensionless) Ditch Length = 150 LF
Slope = 0.001 (ftlft) Highest Elevation = 16.5
Z Required = 27.65 Ratio Lowest Elevation = 16.35
Side Slope (M) _ :1
Flow Depth (Y) = 1.75 ft 21-0 in
Bottom Width (B) = 6.00 ft 72.0 in
Freeboard = 0,.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.11 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45 A.
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12" 922"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 IP300 8.00
New A = 28.88 SF Hydraulic Residence Time
New P = 27.29 Wetted perimeter L=240V
New R = 1.06 Hydraulic radius V- 0.625
Z Actual = 29.98 Must be greater than z required=> 27.65 Okay
New V = 1.22 fps
HRT= 2.0'
Liner: Grass #NIA LB/SF > 0.11 LB/SF #NIA
Top Width 33 ft =
Min. Ditch Depth = 2.25 ft r-------------
_____
Flow Depth (Y) = 1.75 ft
1
Bottom Width (B) = 6 ft
I Min. Ditch De th ft Bottom Width ft Flow Depth ft Top Width ft Side Slorm
2.25 6.00 1.75 1 33 1 6:1
a
Grass I "RED IS USER INPUT
LATEST REVISION: 3/25/2021 10:27 AM
I-�

_ a s14 C$•4r .••
OBEM
VEGETATIVE SWA: E IIIA ' CIRCLE K - AIRPORT
IRIII T1MMOMS GRQUu' •-•
Jacob Dooley 37630.054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Watershed Data
Area (A) _ (Acres)
Coef. (C) _ (Dimensionless)
Inte. (1) _ (inlhr)
Flow (Q10) = 7.5 (cfs)
'F )
Line channel with: a " rip -rap (Assume 6" even if using grass)
Manning n = (Dimensionless) Ditch Length = LF
Slope = 0.003 (ft/ft) Highest Elevation =
Z Required = 2.62 Ratio Lowest Elevation =
Side Slope (M) _ :1
Flow Depth (Y) _ ,0.85 ft 7.8 in U1111111111111mi
Bottom Width (B) = 5.00 ft 60.0 in
T = 0.14 LB/SF
Jute Net 0.45
Curled Mat 1.55
Class A (4"@9"THK) 2.00
Class B (8"@18"THK) 3.50
Class 1 (12"@22"THK) 6.00
Class II 18" 30"THK 7.50
NewA= 4.52 SF
0.35 ft 4.2 in
Y = Weight of water (62.4 LBX
D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
r.
S75
-
1.55
S150
1.75
SC150
2.10
C125
2.25
P300
8.00
New P = 9.11 Wetted perimeter
New R = 0.50 Hydraulic radius
Z Actual = 2.83 Must be greater than z required=> 2.62 Okay
New V = 1.80 fps
DesignMinimum ry
Liner: North American Green, S75 1.55 LB/SF > 0.14 LB/SF Okay
h-----------------------------------------------
Top Width = 11 ft
Min. Ditch Depth, = 1 ft ______________
3 Flow Depth (Y) = 0.65 ft
1
Bottom Width (B) = 5 ft
r
Min. Ditch Depth ft Bottom Width ft
Flow Depth ftTop Width (ft) Side Slope
1.00 5.00
0.65 11 1 3:1
r
North American Green, S75
'RED IS USER INPUT
LATEST REVISION: 1/14/2021 10:40 AM

s �4
VEGETATIVE SWALE: 11113 f e' •�t�s��
0 CIRCLE K-AJRPORT
TIMMOMS GROUP -• �'
Jacob Dooley x - 37630.054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) _ (Acres)
Coef. (C) _ (Dimensionless)
Inte. (1) = (in/hr)
Flow (Q10) _._ (cfs)
IT
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = 60 LF
Slope = 0.003 (ft/ft) Highest Elevation = 12.8
Z Required = 9.05 Ratio Lowest Elevation = 12.61
Side Slope (M) _ :1
P Quintiti et IbitchWidth
Dept
Flow Depth (Y) = 1.15 ft 13.8 in
Bottom Width (B) = 6.00 ft 72.0 in
Freeboard = 0-10 ft 1.2 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.23 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
'I i-e1..� _
Jute Net 0.45 �::,- ;
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
bete nn i ne If Z-
New A = 10.87 SF
New P = 13.27 Wetted perimeter
New R = 0.82 Hydraulic radius
Z Actual = 9.51 Must be greater than z required=> 9.05 Okay
New V = 2.45 fps
■. .
Liner: North American Green, S75 1.55 LB/SF > 0,23 LB/SF Okay
t-------------------------------------- ------ -�
Top Width = 13.5 ft
Min. Ditch Depth = 1.25 X -------------------
3 Flow Depth (Y) = 1.15 ft
1
Bottom Width (B) = 6 ft
Min. Ditch Depth ft Bottom Width ftFlow Depth (ft) , Top Width (ft) 'Side Slope i
1.25 6,00 IIA5 13.5 1 3:1
North American Green, S75 *RED IS USER INPUT
LATEST REVISION: 1/14/2021 10:42 AM

PeMI NG,
00 be Poo tyVW Q)
**4r4
7pM
� ■ S r ORMWATER MANAGEMENT PERM 7 A.PPL ICATIO � FORM
f� a_
a►EWR �� 4' 1 GE.i3TIFiCAMON APFLICATtGa FORM
}yT
■✓1N`t MTERMN EV QI,l
This form mint be %d ctd, prj5d and su m iVed.
+he Rei, red Marra Chaddi.t (Pout 111) mvzf Je primed, Red (;ft and submitted &n &M a7 #m rpked jnfomtatfon.
L FIRDAWNFONAMil
I
PmAcenarne
CIRCLE K-YnAiRF_GRTBIVD7j'1Lf71NG'Tt'j-,m.115
cvw pn=
RICK w5o FE
Pt= nLmber
Date
3MMI
DalTop area rur1w
PHASE 3A
Site Chwavbristics
Dro-m3e am
213,2'&00
1rperft s area
110,59&00
D a &n 4rWl
1 ED 'n
Pear Ffm Catdati ills
1-7, `vlati dep1h
3..83
n
Ratmi 0, p%4ws1i*nwd
50.0E
fulTem)
Rewal G,
76M
(im llow)
P,G- %i! irl n tf l-} , 24,4-r storm
016
arts
Pre -se imf 1-i'r, 244upew Em
1.38
*%.
P0514 etap+aeent 1-j, 24-tmr L"ealt C=
1.34
I last
Ffw?=1 yr. 244 r ,et cer,:ml
-0,04
`ttm
Stange Vdvmr. Noma -SA 1 asm
1tir m regii� vclunre
14,416,10
fe
FM ded veltore
20.107.30
fe
�'m+�iai ram P�
5�91.00
,1a
Songs voknow sAwabm
1.5'r mmof -ma m
ftv
cm4kvei*mffl yT 20'r=0vdum
Qcst4evdcpmmt 1-w 24-1rr nmA wiLme
vTlatta^e rmdmd voluifle
fe
Pis i&d vtlwr'e
fe
. SefmW shrdge Ytr1wm pvAded
fp
Basin Design Paramebrs
Dmvdwm Ome
3.90
days
SHWT elevation
19.00
isrsl
Basin bob" elevation
14.50
fmsl
Slorage elevation
17.70
fr e1
Bashi side son
3.0
:1
Top elevation
20.75
>rr A
Frees oraidded
1.50
ft
Basil Boftm Dartensions
' Basin IWO
220.30
R
L_ Basin wkldi
27.PO
ft
LerO b oath ratio
800
:1
OK
Raise basin b3tter*:, VLi-it o� a least 2-ft above SF:JVT
OK
OK
OK
OK
F— O"401-Dry EAMAed Del eagm Bm:w%v 3 Paris 1. 611, Design Summary, Page 1 of 3

Additional Information
Total runoff volume captured by basin
Forebay provided
Is basin in a recorded drainage easement?
Does basin capture all runoff at ultimate build -out?
1s a sediment depth indicator included?
Does the basin include a drain?
12.55
ac-in
Forebay is required
N
(Y or N)
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Permit
(to be provided by DWQ)
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & H. Design Summary, Page 2 of 3
L

Permit
l#l, WORED.f117115111l5 CF 0411S'T :
(to be provided by DWQ)
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
_RB 1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Basin dimensions,
Pretreatment system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Overflow device, and
Boundaries of drainage easement.
RB_ 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
- Basin dimensions
- Pretreatment system,
Maintenance access,
- Outlet structure,
- Overflow device,
Flow distribution detail for basin inflow, and
Vegetation specifications.
_RB 3. Section view of the basin 0" - 20' or larger) showing:
- Side slopes, 3:1 or lower,
Pretreatment and treatment areas, and
- Inlet and outlet structures.
_RB 6. A construction sequence that shows how the dry detention basin will be protected from sediment until the
entire drainage area is stabilized.
_RB 7. The supporting calculations.
_RB _ 8. A copy of the signed and notarized operation and maintenance (0$M) agreement.
_R8 9. A copy of the deed restrictions (if required).
_RB _ 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Dry Extended Detention Basin-Rev.3 Part III. Required Items Checklist, Page 3 of 3

Peatiit 0-
(10 beWmgdigd by DM)
870R 1b"LATER PAMAGEADF PEPIAIT APPLJCA,T40N 'FORE,
401 COMFiCATION AMICA71ON FORM
1�� fcrm rrsrs3 to f'�'ed rxit, yrira#erl and s�mQl>?d.
Tfe Required Gems CheckV fPeo fib; rrW be pMed, %. d flu# and a&rrft-d afar rrdh aR the required inbmatior.
"L PRQ,IECT#�ORMRi�OM
Ptied nacre
ORaE K- Nn A1;0KW. 3Oy D ill I1. 111.1Gr^.;1- a � 116
FIiCT.e 77L'IrT.]ur
9194664939
Late
3162321
vra'nape a malt be,
PHAS 30
W. Mm NVINIO 1—M
Sft Characbrisdos
Dr*.age ara
7=59 co ie
3rrp it cw as
v67, :i;0 e
% ms
OAD
zfttr :i'de;h
11-9 in
tts Flow C"loons
1 yr,24-Jirrainfall
3M
fttm 3 C,1 "Oprzem
50.00
{w,vv+�ms)
WCnal C,
noo
wiseg)
idama8 zAnsity 1yr, 24-hralorm
0.16
inAsr
Pna-isatis 3 3 y , 24'n;zh Raga
8A9
ielsoc
Fast developrwd 1yr 24-a rr pe* fj=
1.37
lelwc
Preftait1y1,24-}Tpeak
722
R?,WC
'�%k CAijG-.
StorageWm ; Norr-tiAWaha
;nrim aeg:lmd vclma
46,037.00
l?
4
$1,i;4&g-u
##'
OK
g' t
Sedivwtat slo mp Valm provided
15P 1 SD
f?
OK
a �
r
> a 17olame: SA Waters
y�
1.5° r.MV Mucus
Prs-d€vel tl-yr,244uT4mcfiwiy7re
* W. & `
PedAeudopmelt'-Yr,24-tirroe-ic'u%e
P3
/iN1NM
#Yz4n era rmitke d vz!um
1?
POovided vd UM
Se&W4 sisrege vDtume prfl`r'dJ
Basin Design paramours
OtaltkAM time
3.00
says
OK
SHWreleva6an
MOD
fnw
Bay bum ekwayGn
13.25
brA
Raise basin bottom, klust be at ieast 2-ft above SHWT
Swrapekvalim
16.50
faw
Basin side slopes
3.0
:1
OK
Top ohrre m
20.00
hTW
OK
Fm*wM pied
1.5c
tt
OK
Basin Bottom 011monsilorts
Basin 160
MOM
A
Be* width
51.00
is
Length to WWth ratio
13.00
:1
OK
Fcrm SW401-Ory Ex�srdW 5e! ndw flasin-Rov.3 Parts ! & V aeear. Summary Page ' d 2

Additional Information
Total runoff volume raptured by basin
Forebay provided
Is basin in a recorded drainage easement?
Does basin capture all runoff at ultimate build -out?
Is a sediment depth indicator included?
Does the basin include a drain?
44.83
ac-in
Forebay is required
N
(Y or N)
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Permit
(to be provided by DWQ)
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 2 a12

Permit No
. ITEMS 01FECKLI.Sl1'
(to be provided by DWQ)
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
_RB 1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
Basin dimensions,
Pretreatment system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Overflow device, and
Boundaries of drainage easement.
_RB 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
- Basin dimensions
- Pretreatment system,
Maintenance access,
Outlet structure,
Overflow device,
Flow distribution detail for basin inflow, and
Vegetation specifications.
3. Section view of the basin (1" 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
_RB 6. A construction sequence that shows how the dry detention basin will be protected from sediment until the
entire drainage area is stabilized.
_RB 7. The supporting calculations.
_RB 8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
_RB 9. A copy of the deed restrictions (if required).
_RB _ _ 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
LForm SW401-Dry Extended Detention Basin-Rev.3
Part III. Required Items Checklist, Page 3 of 3

Permit Number
(to be provided by OWQ)
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
GRASSED SWALE SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must also be filled out, printed and submitted along with all of the required information.
#" IN . _,lye , .
Project name
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
Contact name
RICK BAKER, PE
Phone number
919-066-4939
Date
January 14, 2021
Drainage area number
Phase 3B
Site Characteristics
Drainage area
680,076.00 ft
Impervious area
367,596.00 ft2
Percent impervious
54.1 % %
Design rainfall depth
0.75 inch
Peak Flow Calculations
10-yr storm runoff depth
NIA in
10-yr storm intensity
0.75 inlhr
Post -development 10-yr storm peak flow
8.80 ft3lsec
Velocity
Maximum non -erosive velocity (peak 10-year storm)
5.00 ft/sec
Soil characteristics (enter "x" below)
Sand/silt (easily erodible)
x
Clay mix (erosion resistant)
Grass Type (enter "x" below)
Bermuda
x.
Tall fescue
Bahiagrass
Kentucky bluegrass
Grass -legume mixture
Swale type: Fill out one of the options below:
Ootion 1: Curb Outlet Swale:
N
(Y or N)
Maximum velocity
Side slopes
:1
Swale length
R
Option 2: Swale Seeking Pollutant Credit ("For -Credit' Swalel:
Y
(Y or N)
Maximum velocity for 10-yr storm
0.60
ftlsec OK
Side slopes
5.00
:1 OK
Swale length
150.00
ft OK
Ql i114tJZ#
Form SW401-Grassed Swale-Rev.4 Parts I and H. Project Design Summary, Page 1 e 3

Permit Number:
(to be provided by DWQ)
Swale Characteristics
Swale Shape: Enter an Y' in the appropriate cell below:
Trapezoidal
x
Parabolic
V-shaped
Width of the bottom of the swale
27.00 ft
Width of the top of the swale
34.50 ft
Additional Information
Is the Swale sized for all runoff from ultimate build -Out?
Y, or N)
OK
Is the BMP located in a proposed drainage easement with a
recorded access easement to a public Right of Way (ROW)?
Y (Y or N)
OK
What is the distance from the bottom of the Swale to the SHWT?
-5.45 ft
Insufficient distance to SHWT, unless conveyance swale only.
What is the ground level elevation?
20.67 fmsl
What is the elevation of the bottom of the swale?
14.55 fmsl
What is the SHWT elevation?
20.00 fmsl
What is the longitudinal slope of the swale?
0.20 %
OK
What is the depth of freeboard?
0.26 ft
OK
Form SW401-Grassed Swale-Rev.4 Pa,'s I and II. Protect Design Summary, Page 2 of 3

Permit No:
(to be assigned by DWQ)
n. gpqwkw tru Q KKUST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package
will result in a request for additional information. This will delay final review and approval of the project. Initial in the space
provided to indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial
below. If a requirement has not been met, attach justification.
Initials Pagel Plan
Sheet No.
RB 1: Plans 0" = 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Swale dimensions (width, length, depth),
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
Grass species, and
Boundaries of drainage easement.
_RB 2. Plan details (1" = 50' or larger) for the grassed Swale showing:
Swale dimensions (width, length, depth),
Maintenance access,
- Proposed drainage easement and public right of way (ROW),
Design at ultimate build -out,
- Grass species,
- Off -site drainage (if applicable),and
Boundaries of drainage easement.
_RB 3. Section view of the grassed swale (1" = 20' or larger) showing:
Side slopes,
Longitudinal slope,
- Freeboard
Swale dimensions, and
- SHWT level(s)
_RB 4. Supporting calculations (including maximum velocity calculations for applicable storms)
_RB _ 5. A copy of the signed and notarized operation and maintenance (0&M) agreement.
_RB _ 6. A copy of the deed restrictions (if required).
SW401-Grassed Swale. Rev.3 Part III, Page 3 of 3

STORMWATER OPERATION AND MAINTENANCE
AGREEMENT

Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Dry Extended Detention Basin
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
The dry extended detention basin system is defined as the dry detention basin, outlet
structure, pretreatment including forebays and the vegetated filter if one is provided.
This system (check one):
® does ❑ does not incorporate a vegetated filter at the outlet.
This system (check one):
® does ❑ does not incorporate pretreatment other than a forebay.
Important maintenance procedures:
- The drainage area will be managed to reduce the sediment load to the dry
extended detention basin.
- Immediately after the dry extended detention basin is established, the vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- No portion of the dry extended detention pond will be fertilized after the first
initial fertilization that is required to establish the vegetation.
- I will maintain the vegetation in and around the basin at a height of
approximately six inches.
- Once a year, a dam safety expert will inspect the embankment.
After the dry extended detention basin is established, it will be inspected once a quarter
and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in
a Coastal County). Records of operation and maintenance will be kept in a known set
location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
Potential roblem:
How I will remediate the roblem:
The entire BMP
Trash debris is present.
Remove the trash/debris.
The perimeter of the dry
Areas of bare soil and/or
Regrade the soil if necessary to
extended detention
erosive gullies have formed.
remove the gully, and then plant a
basin
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Form SW401-Dry Detention O&M-Rev.3
Page I of 4

B,I[F element:
The inlet device: pipe or
swale
main treatment area
Potential problem:
Tiv pipe is clogged f'd
The pipe is cracked or
otherwise damaged (if
Erosion is occurring in the
Swale (if applicable)_
Sediment has accumulated
and reduced the depth to 75-�
of the original design depth
(see diagram below) -
Erosion has occurred or
riprap is displaced.
Weeds are present.
Sediment has accumulated
and reduced the depth to 75%
of the original design depth
(%-,ee diagram below) -
Water is standing more than
5 days after a storm event.
Weeds and noxious plants are
growing in the main
treatment area.
How i will remediate theyrobl
Unclog the pipe. Dispose of the
sediment off -site.
Replace the pipe.
Regrade the Swale if necessary to
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Search for the source of the
sediment and remedy the problem if
pole. Remove the sediment and
dispose of it in a location, where it
will not cause impacts to streams or
the BW.
Phn-ide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problem.
Remove the weeds, preferably by
hand. 7f pesticides are used, wipe
them on the plants rather than
Search for the source of the
sediment and remedy the problem if
possible. Remove the sediment and
dispose of it in a location rdwte it
will not cause impacts to streams or
the B-N4P. Revegetate disturbed
areas immediately with sod
(preferred) or seed protected with
securely staked erosion mat.
Check outlet structure for clogging.
If it is a design issue, consult an
Remove the plants by hand or by
wiping them with pesticide (do not
Form SW401-Dry Detention O&M-Rev-3 Page 2 of 4

BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
I Shrubs or trees have started
Remove shrubs or trees
to grow on the embankment.
immediately.
Grass cover is unhealthy or
Restore the health of the grass cover
eroding,
- consult a professional if necessary.
Signs of seepage on the
Consult a professional.
downstream face.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
The outlet device
Clogging has occurred.
Clean out the outlet device. Dispose
of the sediment off -site.
The outlet device is damaged_Repair
or replace the outlet device.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
The measuring device used to determine the sediment elevation shall be such that it will
give an accurate depth reading and not readily penetrate into accumulated sediments.
When the basin depth reads 15.50 feet in the main pond, the sediment shall be removed.
When the basin depth reads NA feet in the forebay, the sediment shall be removed.
BASIN DIAGRAM
(fill in the blanks)
'temporary Pool Elevalion
Sediment Removal Ek NA T pora Pool
olume Sediment Removal Elevation 13.50
---------------------------I---------
Bottom Etevatio NA 25°to "--"'-
Sediment Bottom Elevation 14.50
Storage
FOREBAY MAIN POND
Form SW401-Dry Detention O&M-Rev3
Page 3 of 4
25%
L

Permit Number:
(to be provided byDWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify D WQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:CIRCLE K - iVTI AIRPORT BLVD WILiVllNGTON - NC 1 i 5
BMP drainage area number -PHASE 3A
Print natne:GRANSEUR DICK
TitleXACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD. WILIdINGTON, NC 28405
Signature:
Date: t/917.0 z 0
Note: The legally responsible party should not be a homamrers assomat en uaiess more than 5w,� of
the lots have been sold and a resident of the subdivision has been named die president.
I, Ram (". -avu , a Notary Public for the State of
�trrt& , County of Nu N-alrodfe- , do hereby certify that
personally appeared before me this
day of ,240Q0, and acknowledge the due execution of the
forgoing dry detention basin maintenance requirements. Witness my hand and official
seal, P40 M - lNoaMt�
'° M N �
a NOTARY
PUBLIC i
ti'
�I,IER COS-5)
SEAL
My commission expires 124 9
Form SW401-Dry Detention O&M-Rev.3 Page 4 of 4

Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Dry Extended Detention Basin
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
The dry extended detention basin system is defined as the dry detention basin, outlet
structure, pretreatment including forebays and the vegetated filter if one is provided.
This system (check one):
® does ❑ does not incorporate a vegetated filter at the outlet.
This system (check one):
® does ❑ does not incorporate pretreatment other than a forebay.
Important maintenance procedures:
- The drainage area will be managed to reduce the sediment load to the dry
extended detention basin.
- Immediately after the dry extended detention basin is established, the vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- No portion of the dry extended detention pond will be fertilized after the first
initial fertilization that is required to establish the vegetation.
-- I will maintain the vegetation in and around the basin at a height of
approximately six inches.
- Once a year, a dam safety expert will inspect the embankment.
After the dry extended detention basin is established, it will be inspected once a quarter
and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in
a Coastal County). Records of operation and maintenance will be kept in a known set
location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
Trash debris is present.
Remove the trash/debris.
The Perimeter of the dry
Areas of bare soil and/or
Regrade the soil if necessary to
extended detention
erosive gullies have formed.
remove the gully, and then plant a
basin
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Form SW401-Dry Detention O&M-Rev.3
Page 1 of 4
N

The inlet devices pipe or The pipe is clogged (If
Swale applicable) -
The pipe is cracked or
vdmwise damaged f of
The main treatment area
Erosion is occurring in the
Swale (if apph;able)-
Sediment has accumulated
and reduced the depth to 75 %
of the original design depth
{see diagram below).
Eresicm has occurred or
dPmP is displaced -
Weeds are present
Sediment has arr•mudated
and reduced the depth to 75,,:
of the original design depth
(seQ diagram below).
Water is standing more than
5 days after a storm event.
Weeds and aoxious plants are
growing in the main
treatment area.
How I will remediate the probl
Unclog the pipe- Dispose of the
sediment off -site
Replace the P4v-
Regrade the ssvale if necessary to
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to a - mid
future problems with erosion.
Search for die source of the
sediment and remedy the problem if
possible. Remove the sediment and
dispose of it in a location where it
will not cause imparts to streams or
the BW.
Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erasion problems.
Remove the weeds, preferably by
hand. If pesticides are used, wipe
them on the plants rather than
Search for the source of the
sediment and remedy the problem if
possible. Remove the sediment and
dispose of it in a location where it
will not cause impacts to streams or
the BW Revegetate disturbed
areas immediately with sod
(preferred) or seed protected with
securely staked erosion mat.
Check outlet structure for clogging.
If it is a design issue, consult an
Remove the plants by hand or by
wiping them with pesticide (do not
Foam SW401-Dry Detention O&M-Rev.3 page 2 of 4

BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
Shrubs or trees have started
Remove shrubs or trees
to grow on the embankment.
immediately.
Grass cover is unhealthy or
eroding,
Restore the health of the grass cover
- consult a professional if necessarV.
Signs of seepage on the
Consult a professional.
downstream face.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
The outlet device
Clogging has occurred.
Clean out the outlet device. Dispose
of the sediment off -site.
The outlet device is damaged
Repair or replace the outlet device.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
The measuring device used to determine the sediment elevation shall be such that it will
give an accurate depth reading and not readily penetrate into accumulated sediments.
When the basin depth reads 15.00 feet in the main pond, the sediment shall be removed.
When the basin depth reads NA feet in the forebay, the sediment shall be removed.
Sediment Removal
Bottom
FOREBAY
BASIN DIAGRAM
011 in the blanks)
Sediment
Storage
Temporary Ppal Elevation 1 00
Pool
-----Sediment Removal_ - Elevation15.00--
Bottom Elevation
MAIN.POND
Form SW401-Dry Detention O&M-Rev.3 Page 3 of 4
25%

Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: —CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
BMP drainage area numberTHASE 3B
Print name:GRANSEUR DICK
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address: 1740 AIRPORT BLVD_ WILMLNGTON NC 28405
Signature:
Date: 90 20 X O
NOW: The legally responsible party should not be a homeowners association unless more than 59% of
the lots have been sold and a resWent of the subdivision has been named the president.
'Rase- M • IbAit S , a Notary Public for the State of
A&- "I tYL. , County of &Q„J HPvtmwr , do hereby certify that
tAtr1�GK r tGk.• Personally appeared before me this
day of t' , and acknowledge the due execution of the
forgoing dry detention basin maintenance requirements. Witness my hand ands oiiicial
seal,. i 1
NOTARY
PU13LIC a
y9y
SEAL
My commission expires qt I a I zY
Form SW401-Dry Detention O&M-Rev.3
Page 4 of 4

Permit Name:
(to be provided by DWQ)
Drainage Area Number:
Grassed Swale Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important maintenance procedures:
— The drainage area of the grassed swale will be carefully managed to reduce the
sediment load to the grassed swale.
— After the first-time fertilization to establish the grass in the swale, fertilizer will
not be applied to the grassed swale.
The grassed swale will be inspected once a quarter. Records of operation and
maintenance will be kept in a known set location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
Potentialproblem:
How I will remediate the problem:
The entire length of the
Trash/debris is present.
Remove the trash/debris.
swale
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then re -sod
(or plant with other appropriate
species) and water until established.
Provide lime and a one -titre
fertilizer application.
Sediment covers the grass at
the bottom of the swale.
Remove sediment and dispose in an
area that will not impact streams or
BMPs. , R—sod i? n&ess
Vegetation is too short or too
Mairtain vegetatiorLat,a height of
long.
approximatelyappr6ximately six inches.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit;at 919-
1
outlet.
733-1786.
Form SW401-Grassed Swale O&M-Rev.3 Page 1 of 2

Permit ',Niunber:
(to bs provided ly MQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: IRCLE K - N I AIRPORT BLVD WILMINGTON - NC. 1 i
BMP drainage area nismber.PHASE 3A
Print name:+GRANSEUR .DICK
TitleXACILiTIES DIRECTOR - NEW HANOVER COC�'TY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD. WILMINGTON NC 28405
Note: The legally responsible patty should not be a homeowners association unless more than 501'm of
the lots have been sold and a resident of the subdivision has been named the presiders.
1, M . i�)QAi V� a rotary Public for the State of
Nkwi ' "1(W% , County of Kko3 +6nawe t , do hereby certify that
i VML&►Vur —D1(.,Lc_ personally appeared before me this IP"
day of , aC00, and acknowledge the due execution of the
forgoing grassed Swale maintenance requirements. Witness my hand d official seal,
p W 44
z NOTARY
t PUBLIC z
4
,tit Cd*
SEAL
fax M. 1'3au+*--J
My commission expires_ o�t"i
Fottr SW401-Grassed Swale O&M-Rev.3
Page 2 of 2

Permit Name:
(to be provided by DWQ)
Drainage Area Number:
Grassed Swale Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important maintenance procedures:
The drainage area of the grassed swale will be carefully managed to reduce the
sediment load to the grassed swale.
After the first-time fertilization to establish the grass in the Swale, fertilizer will
not be applied to the grassed swale.
The grassed Swale will be inspected once a quarter. Records of operation and
maintenance will be kept in a known set location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
PoEential �roblem:
How I will rentediate the roblem:
The entire length of the
swale
Trash/debris is present.
Remove the trash/debris.
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then resod
(or plant with other appropriate
species) and water until established.
Provide lime and a one-time
fertilizer application.
Sediment covers the grass at
the bottom of the Swale.
Remove sediment and dispose in an
area that will not impact streams or
BMPs.. Re=sod,if necessary.
Vegetation is too short or too
Maiptai vegetatfon at "a,�eight of
_
long.
a ioximatel six inches.
The receiving water
Erosion or other signs of
Contact the.NC Division of --Water
damage have occurred at the
outlet.
Quality 401'. Oye�rsight Unit -at 919-
733-1786. " `
Form SW401-Grassed Swale O&M-Rev.3
Page 1 of 2
L

Permit Number:
MP be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC 115
BMP drainage area number:PHASE 3B
Print name:GRANSEUR DICK _
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD. WIL UNGTON NC 28405
Signature:
Date:
yd2-O
Note: lire legally responsible pang► should not be a homeowner association unless mom than We of
the lots ime been sold and a resident of fire mtbd3viston has been natured the pn ssdens.
I, & M� a Notary Public for the State of
KINIL"t t w^3�%l, County of kkoz Hw"JR e— , do hereby certify that
S—CPA4.e-- ick- personally appeared before me this
day of —• ?OZO , and aciknOwledge the due execution of the
forgoing grassed swale maintenance requirements. Witness my hand and official seal,
OP M
a- I P-fq;
(:D
SEAL
Kwm.-,)ruAJ
My commission expires qkiy
Form SW401-Grassed Swale O&M-Rev.3 Page 2 of 2

MISCELLANEOUS CALCULATIONS
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PD1 CIRCLE K - AIRPORT
JacobDoole 0 � YIMMONS GROUP R'
Y :1P . , 37630.054
Drainage Ditch Design (Velocity Constraint)
129-"T MOW "' e a -e
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) =
1.81 (Acres)
Coef. (C) =
0.55 (Dimensionless)
Inte. (1) =
7.75 (in/hr)
Flow (Q10) =
7.7 (cfs)
Line channel with:
6 " rip -rap (Assume 6" even if using grass)
Manning n =
0.030 (Dimensionless) Ditch Length LF
Slope =
0.016 (ft/ft) Highest Elevation
Z Required =
1.24 Ratio Lowest Elevation =
Side Slope (M) =
:1
Variable Quantities (Oiteh WdVIA Depth)
Flow Depth (Y) = 0.35 ft 4.2 in
Bottom Width (B) = 7.75 ft 93.0 in
Freeboard = 0.65 ft 7.8 in
Com,pute Tractive Force
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.34 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net
0.45
Curled Mat
1.55
Class A (4"@9"THK)
2.00
Class B (8'@18"THK)
3.50
Class I (12"@22"THK)
5.00
Class II 18" 30"THK
7.50
S75
1.55
S 150
1.75
SC150
2.10
C125
2.25
P300
8.00
New A = 3.08 SF
New P = 9.96 Wetted perimeter
New R = 0.31 Hydraulic radius
Z Actual = 1.41 Must be greater than z required=> 1.24 Okay
New V = 2.83 fps
Minimum Design Geometry
Liner: North American Green, S75 C55 LB/SF > 0.34 LB/SF Okay
h---------- ---------------------------- - --- --1
jTopidth = 13.75 ft
Min. Ditch Depth= 1 ft Flow Depth (Y) = 0.35 ft
Bottom Width (B) = 7.75 ft
r -
Min. Ditch IDe th ft Bottom Width ft Flow Depth ft Top Width ftSide Slo i
1.00 7,75 1 0.35 1 13.75 1 3:1
North American Green, S75 7 *RED IS USER INPUT
LATEST REVISION: Ill1/2021 9:44 AM

r w191aa0�r -s
PD4 0 % CIRCLE K -AIRPORT
r- MONS GaGV, Nummmmomm
Jacob Dooley rnrs I aT3101h I vtr w vs 37630 054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Area (A) = 1.06 (Acres)
Coef. (C) = 0.81 (Dimensioinle�;s)
Inte. (1) = 9.70 (in/hr)
Flow (Q10) = 8.3 (cfs)
lur"MR4,71M.
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = LF
Slope = 0.011 (ft/ft) Highest Elevation
Z Required = 1.58 Ratio Lowest Elevation
Side Slope (M) = :1
Flow Depth (Y) = 1.00 ft 12.0 in
Bottom Width (B) = 0.00 ft 0.0 in
Freeboard = 0.00 ft 0.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.70 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 IP300 8.00
(Dowmigne W7 Adual 6e &1aWeiftk g
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual = 1.82 Must be greater than z required=> 1.58 Okay
New V = 3.20 fps
■:
Liner: North American Green, S75 1.55 LB/SF> 0.71 LB/SF Okay
Top Width = 6 ft
Min. Ditch Depth '= 1 ft
3 Flow Depth (Y) = 1 ft
1
Bottom Width (B) = 0 It
Min. Ditch Depth ftBottom Width ft Flow Depth (ft) I Top Width (ft) iSide Slopeq
1.00 0,00 1 1.00 i 6 1 3:1
■
North American Green, S75 *RED IS USER INPUT
LATEST REVISION: 3/7/2021 2:21 PM

P05 A CIRCLE K -AIRPORT
Jacob DooleyE 1. 37630 054
Drainage Ditch Design (Velocity Constraint)
Rim
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
EEMM=
Area (A) = 1.53 (Acres)
Coef. (C) = 0.79 (Dimensionless)
Inte. (1) = 9.70 (in/hr)
Flow (010) = 11.7 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = (Dimensionless) Ditch Length = 130 LF
Slope = 0.003 (ft/ft) Highest Elevation = 22.51
Z Required = 4.10 Ratio Lowest Elevation = 22.08
Side Slope (M) _ :1
MIT
Flow Depth (Y) = 1.50 ft 18.0 in
Bottom Width (B) = 0.00 ft 0.0 in
Freeboard = 0.00 ft 0.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.31 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45
Curled Mat 1.55 S75 1.55
Class A (4" @9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 P300 8.00
New A = �6.75 SF
New P = 9.49 Wetted perimeter
New R = - 0.71 Hydraulic radius
Z Actual = 5.38 Must be greater than z required=> 4.10 Okay
New V = 2.28 fps
Design
Liner: North American Green, S75 1.55 LB/SF> 0.31 LB/SF Okay
N
Top Width = 9ft
Min. Ditch Depth= 1.5 ------------------
Xl
Flow Depth (Y) = 1.5 ft
Bottom Width (B) = 0 ft
Min. Ditch Depth ft Bottom Width ft Flow Depth (ft) I Top Width (ft) I Side Slopel
1.50 0.00 1.50 1 9 I Ili
North American Green, S75 *RED IS USER INPUT
LLATEST REVISION: 3/7/2021 2:22 PM

K. aI-E�� *••d - .
PD6 ` W * % CIRCLE K -AIRPORT
• - T1MMa_IS GROUP
Jacob Dooley ..�.... �._.. 1 37630.054
Drainage Ditch Design (Velocity Constraint)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Area (A) = 1.22 (Acres)
Coef. (C) = 0.45 (Dimensionless)
Inte. (1) = 9.70 (in/hr)
Flow (Q10) = 5.3 (cfs)
Known Quantities
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = 685 LF
Slope = 0.007 (ft/ft) Highest Elevation = 23.1
Z Required = 1.33 Ratio Lowest Elevation = 18.64
Side Slope (M) _ :1
Flow Depth (Y) _ " 0.75 ft 9.0 in
Bottom Width (B) = 1.00 It 12.0 in
Freeboard = 0.50 It 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.30 LB/SF D=Depth of flow in channel (ft)
Jute Net
0.45
Curled Mat
1.55
Class A (4" a@9"THK)
2.00
Class B (8"@18"THK)
3.50
Class I (12"A22"THK)
5.00
Class II 18" 30"THK
7.50
S=Slope of channel (ft/ft)
S75
1.55
S150
1.75
SC150
2.10
C125
2.25
P300
8.00
i
NewA= 2.44£SF
New P = 5.74 Wetted perimeter
New R = 0.42 Hydraulic radius
Z Actual = 1.38 Must be greater than z required=> 1.33 Okay
New V = 2.26 fps
Liner: North American Green, S75 1.55 LB/SF > 0.31 LB/SF Okay
Top Width = 8.5 ft
Min. Ditch Depth '= 1.25 ft - _ ___
I 3 Flow Depth (Y) = 0.75 ft
i1
Bottom Width (B) = 1 ft
Min. Ditch Depth ft Bottom Width (ft) Flow Depth (ft) f Top Width (ft) Side Slope
1.25 1 1.00 0.75 8.5 1 3.1
Ditch
North American Green, S75
"RED IS USER INPUT
LATEST REVISION: 3/7/2021 2:22 PM

PD7 CIRCLE K - AIRPORT
TIMMONIS GROUP
Jacob Dooley _ 37630.054
Drainage Ditch Design (Velocity Constraint)
-■
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) = 0.50 (Acres)
Coef. (C) = 0.50 (Dimensionless)
Inte. (1) = 9.70 in/hr
( )
Flow (Q,o) = 2.4 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = LF
Slope = 0.046 (ft/ft) Highest Elevation =
Z Required = 0.23 Ratio Lowest Elevation =
Side Slope (M) = 3 :1
Flow Depth (Y) = 0.50 ft &0 in
Bottom Width (B) = 2.00 ft 24.0 in
Freeboard = 0.50 ft 6.0 in
Compute Tractive ForceL�--
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 1.43 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
RTITATIIII�-_1
Jute Net
0.45
Curled Mat
1.55
Class A (4"@9'7HK)
2.00
Class B (8"@18"THK)
3.50
Class I (12"@22"THK)
5.00
Class II 18" 30"THK
7.50
S75
1.55
S150
1.75
SC150
2.10
C125
2.25
P300
8.00
AM M7 .. _
New A= 1.75 SF
New P = 5.16 Wetted perimeter
New R = 0.34 Hydraulic radius
Z Actual = 0.85 Must be greater than z required=> 0.23 Okay
New V = 5.18 fps
Liner: North American Green, S75 1.55 LB/SF > ; 44 LB/SF Okay
h--------------------------------------------- -",
Top Width = 8 ft
Min. Ditch Depth = 1 ft
3 Flow Depth (Y) = 0.5 ft
11
Bottom Width (B) = 2 ft
a
Min. Ditch Depth(ft) Bottom Width ft Flow Depth ftTop Width ft Side Slope
1.00 2.00 1 0.fi0 8 3:1
e
North American Green, S75 *RED IS USER INPUT
LATEST REVISION: 9/1/2020 2:01 PM

PD8 CIRCLE K - AIRPORT
EA 1'IE�T�iEi`"� TIMMONS GROUP
Jacob Dooley , 37630.054
Drainage Ditch Design (Velocity Constraint)
PERMANIENT DIVERSION DlTr7L.-�D8
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) _ ' "" (Acres) '*
Coef. (C) _ (Dimensionless)
Inte. (1) _ (in/hr)
Flow (il = 7.2 (cfs)
Line channel with: f " rip -rap (Assume 6" even if using grass)
Manning n = 0.0,ar (Dimensionless) Ditch Length = 50 LF
Slope = 0.006 (ftfft) Highest Elevation = 19.16
Z Required = 1.85 Ratio Lowest Elevation = 18.85
Side Slope (M) _ , :1
offirauraffm 51--
Flow Depth (Y) = 0.75 ft 9.0 in
Bottom Width (B) = 2.00 ft 24.0 in
Freeboard = 0.25 ft 3.0 in
I Compute Tractive Fo
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.29 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
Jute Net 0.45 , , ;
Curled Mat 1.55 S75 1.55
Class A (4" Q9"THK) 2.00 S150 1.75
Class B (8" @18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II 18" 30"THK 7.50 1 P300 8.00
a, M.Mml
New A =
3.19 SF
New P =
6.74 Wetted perimeter
New R =
0.47 Hydraulic radius
Z Actual =
1.93 Must be greater than z required=> 1.85 Okay
New V =
2.37 fps
Minimum Design Geometry
Liner: North American Green, S75 1.55 LB/SF > 0.3 LB/SF Okay
---------------------------- ------------------
-
Top Width = 8 ft
Min. Ditch Depth1 ft
3 Flow Depth (Y) = 0.75 ft
1
Bottom Width (B) = 2 ft
Min. Ditch Depth ft Bottom Width ftFlow Dt: th ftTop Width ft Side Slope
1.00 2.00 n 775 I R Iz•,
e
North American Green, S75 *RED IS USER INPUT
L. LATEST REVISION: 9/1/2020 2:03 PM

PD9 *. mil' CIRCLE K - AIRPORT
LITY, TIMMOMS GROUP mcm r:
Jacob Dooley _ 37630.054
Drainage Ditch Design (Velocity Constraint)
',PERMANENT DIVERSION DITCH[ -,•
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) = 0.74 (Acres)
Coef. (C) = 0.65 (Dimensionless)
Inte. (1) = 9.70 (in/hr)
Flow (Q10) = 4.7 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = 432 LF
Slope = 0.004 (ft/ft) Highest Elevation = 24.71
Z Required = 1.49 Ratio Lowest Elevation = 23
Side Slope (M) = 3 :1
FlowDepth(Y) = e 0-78 ft 9.4 in
Bottom Width (B) = 1.00 ft 12.0 in
Freeboard = 0 00 ft 0.0 in
1. N �I•+fr `I : a �t . t.:: -- ---- - --
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.19 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (f 1ft)
Jute Net
0.45
Curled Mat
1.55
Class A (4"@9"THK)
2.00
Class B (8"@18"THK)
3.50
Class I (12"@227HK)
5.00
Class II 18" 30"THK
7.50
_..
S75 1.55
S150 1.75
SC150 2.10
C125 2.25
P300 8.00
Determine If Z Actual Is Greater than Z Requiredr
New P = 5.93 Wetted perimeter
New R = 0.44 Hydraulic radius
Z Actual = 1.50 Must be greater than z required=> 1.49 Okay
New V = 1.81 fps
Minimum Design Geometry
Liner: North American Green, S75 1.55 LB/SF > 0.2 LB/SF Okay
t____ Top Width = 5.68 ft
Min. Ditch Depth= 0.78 ft _____________r____.
3 Flow Depth (Y) = 0.78 ft
�1
Bottom Width (B) = 1 ft
Min. Ditch Depth ft Bottom Width ft j Flow Depth (ft) I Top Width (ft) Side Slope
0.78 1.00 0.78 5.68 3.1
NEIRIMM
North American Green, S75 *RED IS USER INPUT
LATEST REVISION: 1/11/2021 11:37 AM

'c�¢� --•
VEGETATIVE SWALE IIIA * CIRCLE K -AIRPORT
Jacob y TIMMONS GROUP •-• =
,Rrh ::�c - . 37630.054
Drainage Ditch Design (Velocity Constraint)
DIVERSIONPERM ENT •
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) _ (Acres)
Coef. (C) - (Dimensionless)
Inte. (1) = (in/hr)
Flow (Q10) _ (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = " LF
Slope = 0.003 (f tft) Highest Elevation =
Z Required = 2.62 Ratio Lowest Elevation =
Side Slope (M) = 3 :1
Flow Depth (Y) = 0.65 ft 7.8 in
Bottom Width (B) = 5.00 ft 60.0 in
Freeboard = 0.35 ft 4.2 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.14 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
si d.,•
Jute Net 0.45
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class 11 18" 30"THK 7.50 1 1 P300 8.00
Determine ;f Z Actual Is Greater Thar, Z Required -
y
New P = 9.11 Wetted perimeter
New R = 0.50 Hydraulic radius
Z Actual = 2.83 Must be greater than z required=> 2.62 Okay
New V = 1.80 fps
Liner: North American Green, S75 1-55 LB/SF > 0-14 LB/SF Okay
t------------ - ------------- —--- ------ ------�
Top Width = 11 ft
Min. Ditch Depth = 1 ft
3 Flow Depth (Y) = 0.65 ft
'1
Bottom Width (B) = 5 ft
Min. Ditch Depth ft Bottom Width ftFlow Depth ftTop Width ftSide Slope
1.00 5.00 0.65 11 3:1
North American Green, S75 , *RED IS USER INPUT
LATEST REVISION: 1/14/2021 10:40 AM

0 R LAL 01 --dLr-.,tetzi
VEGETATIVE SWALE IIIB "tip CIRCLE K - AIRPORT
1150"T TNMMONS GROUP
Jacob Dooley -•,-s.c;+ti ;.:'r 37630.054
Drainage Ditch Design (Velocity Constraint)
r lip -
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming
n=0.03 for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will
be correct; select appropriate lining based on tractive force)
Area (A) _ • (Acres)
Coef. (C) _ (Dimensionless)
Inte. (1) = (in/hr)
Flow (Q10) = 25.3 (cfs)
Line channel with: 6 " rip -rap (Assume 6" even if using grass)
Manning n = 0.030 (Dimensionless) Ditch Length = LF
Slope = 0.003 (M) Highest Elevation =
Z Required = 9.05 Ratio Lowest Elevation =
Side Slope (M) = 3 :1
(Ditchrjable Quantities : Depth)
-- -
Flow Depth (Y) = 1.15 ft 13.8 in
Bottom Width (B) = 6.00 ft 72.0 in
Freeboard = 0.10 ft _ 1.2 in
T=YxDxS Y =Weight of water (62.4 LB/CUFT)
T = 0.23 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
FEWi'
Jute Net
0.45
Curled Mat
1.55
Class A (4" @9"THK)
2.00
Class B (8" @18" THK)
3.50
Class I (12" @22°THK)
5.00
Class II 18" 30"THK
7.50
S75 1.55
S150
1.75
SC150
2.10
C125
2.25
P300
8.00
A
New A = 10.87 SF
New P = 13.27 Wetted perimeter
New R = 0.82 Hydraulic radius
Z Actual = 9.51 Must be greater than z required=> 9.05 Okay
New V = 2.45 fps
DesignMinimum
Liner: North American Green, S75 1.55 LB/SF > 0.23 LB/SF Okay
-----------------------------------------------
Top Width = 13.5 ft /�-
Min. Ditch Depth,= 1.25X [___------ _- ---_
i 3 Flow Depth (Y) = 1.15 ft
--------------
Bottom Width (B) = 6 ft
Min. Ditch Depth ft Bottom Width ftFlow Depth (ft) i Top Width (ft) I Side Slope
1.25 6.00 1.15 13.5 1 3:1
North American Green, S75
*RED IS USER INPUT
LATEST REVISION: 1/14/2021 10:42 AM

r x i d.tTj lur'lL 11¢M
{� Circkle K - Wilmington Airport
TIMMONS GROUP
Jacob Dooley d . T, 37630.054
Pipe Outlet Protection (NYDOT Method)
Structure Name: 0.
Pipe Diameter = in From Fig. 8.06.c: ZONE = 2
Pipe Slope = ft/ft
Mannings n = o_' Rip Rap Class = B
Velocity Flowing Full = 5.11 fps Apron Thickness = 18 in
Apron Length = 12.0 ft
Apron Width = 3xDia.= 6.0 ft
From Fig. 8.06.e:
Pipe Diameter =
18 in
From Fig. 8.06.c:
ZONE = 1
f Pipe Slope =
0.003 ft/ft
Mannings n =
0.013
Rip Rap Class =
A
Velocity Flowing Full =
3.26 fps
Apron Thickness =
12 in
Apron Length =
6.0 ft
Apron Width = 3xDia.=
4.5 ft
From Fig. 8.06.e:
Structure Narne: EW200
-- J
Pipe Diameter = 30 in
Pipe Slope _ 0.003 ft/ft
Mannings n = 0.013
Velocity Flowing Full = 4.59 fps
From Fig. 8.06.c: ZONE =
Rip Rap Class = B
Apron Thickness = 18 in
Apron Length = 15.0 ft
Apron Width = 3xDia.= 7.5 ft
•;M'•�i�:�:�
From Fig. 8.06.e:
LLATEST REVISION: 317/2021 2:25 PM

IStructure Name:
M01
Pipe Diameter =
18 in
From Fig. 8.06.c:
ZONE = 1
Pipe Slope =
I
0.0035 ft/ft
Mannings In =
0.013
Rip Rap Class =
A
Velocity Flowing Full =
3.53 fps
Apron Thickness =
12 in
Apron Length =
6.0 ft
Apron Width = 3xDia.=
4.5 ft
From Fig. 8.06.e:
Structure Name: FE303
Pipe Diameter =
24 in
From Fig. 8.06.c:
ZONE _
Pipe Slope =
0.005 fttft
Mannings n =
0.013
Rip Rap Class =
A
I Velocity Flowing Full =
5.11 fps
Apron Thickness =
12 in
Apron Length =
8.0 ft
f
Apron Width = 3xDia.=
6.0 ft
From Fig. 8.06.e:
Structure Name: EW1
02
Pipe Diameter =
24 in
From Fig. 8.06.c:
ZONE = 2
Pipe Slope =
0.0085 ft/ft
Mannings In =
0.013
Rip Rap Class =
B
Velocity Flowing Full =
6.66 fps
Apron Thickness =
18 in
Apron Length =
12.0 ft
Apron Width = 3xDia.=
6.0 ft
From Fig. 8.06.e:
LATEST REVISION: 3/7/2021 2:25 PM

St ure Name: EW1011
f Pipe Diameter= in From Fig. 8.06.c: ZONE
IPipe Slope = ft/ft
Mannings n = Rip Rap Class = A
Velocity Flowing Full = 3.37 fps Apron Thickness = 12 in
Apron Length = 6.0 ft
Apron Width = 3xDia.= 4.5 ft
From Fig. 8.06.e:
Structwe Name:
e
l
Pipe Diameter =
30 in
From Fig. 8.06.c:
ZONE _
Pipe Slope =
0.01 ft/ft
Mannings n =
0.013
Rip Rap Class =
B
Velocity Flowing Full =
8.38 fps
Apron Thickness =
18 in
Apron Length =
15.0 ft
'
Apron Width = 3xDia.=
7.5 ft
From Fig. 8.06.e:
Structure Name: EW21
0
Pipe Diameter =
36 in
From Fig. 8.06.c:
ZONE _ ^
Pipe Slope =
0.01 ft/ft
Mannings n =
0.013
Rip Rap Class =
B
Velocity Flowing Full =
9.46 fps
Apron Thickness =
18 in
Apron Length =
18.0 ft
Apron Width = 3xDia.=
9.0 ft
From Fig. 8.06.e:
LATEST REVISION: 3/7/2021 2:25 PM

I
IStructure Name:
kr
-
r Pipe Diameter =
42 in
From Fig. 8.06.c: ZONE
I{ Pipe Slope =
0.01 ft/ft
Mannings n =
0.013
Rip Rap Class = 1
Velocity Flowing Full =
10.49 fps
Apron Thickness = 24 in
I
Apron Length = 28.0 ft
Apron Width = 3xDia.= 10.5 ft
From Fig. 8.06.e:
Name:Structure
a
Pipe Diameter =
42 in
From Fig. 8.06.c:
ZONE = 3
Pipe Slope =
0.01 ft/ft
Mannings n =
0.013
Rip Rap Class =
1
Velocity Flowing Full =
10.49 fps
Apron Thickness =
24 in
Apron Length =
28.0 ft
Apron Width = 3xDia.=
10.5 ft
From Fig. 8.06.e:
I
Pipe Diameter =
18 in
From Fig. 8.06.c:
ZONE _
Pipe Slope =
0.003 f ift
Mannings n =
0.013
Rip Rap Class =
A
Velocity Flowing Full =
3.26 fps
Apron Thickness =
12 in
Apron Length =
6.0 ft
IApron
Width = 3xDia.=
4.5 ft
From Fig. 8.06.e:
LLATEST REVISION: 3/7/2021 2:25 PM

CIRCLE K - AIRPORT
Jacob Dooley
ifMMONS GROUP --,_5,�; ,IEl4a,l ,•;I
mAvi.6iitvs<�� � i �:aa•,-�,ta •isa:;'igra,=x- 37630.054
Ditch Outlet Protection (NYDOT Method)
DName:D
Velocity =
1.81 fps
From Fig. 8.06.c:
ZONE _
Top Width =
5.68 ft
Ditch Area =
2.6052 sf
Rip Rap Class =
A
Equivalent Pipe Diameter =
21.86 in
Apron Thickness =
12 in
Equivalent Pipe Diameter =
18 in
Apron Length =
6.0 ft
Apron Width = Top Width.=
5.7 ft
From Fig. 8.06.e:
LLATEST REVISION: 3/7/2021 2:27 PM

Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3138 by Autodesk, Inc.
ILIA - 50 YEAR
Trapezoidal Weir
Crest
= Sharp
Bottom Length (ft)
= 15.00
Total Depth (ft)
= 1.50
Side Slope (z:1)
= 4.00
Calculations
Weir Coeff. Cw
= 3.10
Compute by:
Q vs Depth
No. Increments
= 30
Depth (ft)
2.00
I
1.50
1.00
0.50
!- 0.00
L -0.50
❑ 5 10
Weir W.S.
IIIA - 50 YEAR
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
15 20 25 30 35
Sunday, Mar 7 2021
= 0.85
= 43.05
= 15.64
= 2.75
= 21.80
Depth (ft)
2.00
1.50
1.00
0.50
MY
-0.50
40
Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.
(� IIIA -100 YEAR
I
Trapezoidal Weir
Crest
= Sharp
Bottom Length (ft)
= 15.00
Total Depth (ft)
= 1.50
Side Slope (z:1)
= 4.00
Calculations
Weir Coeff. Cw
= 3.10
Compute by:
Q vs Depth
No. Increments
= 30
Depth (ft)
2.00
1.50
1.00
0.50
OO
-0.50
U 5 10 15
Weir W.S.
IIIA -100 YEAR
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
20 25 30
Sunday, Mar 7 2021
= 0.95
= 51.78
= 17.86
= 2.90
= 22.60
Depth (ft)
2.00
1.50
1.00
0.50
M
-0.50
35 40
Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.
111 B - 50 YEAR
Trapezoidal Weir
Crest
= Sharp
Bottom Length (ft)
= 50.00
Total Depth (ft)
= 1.50
Side Slope (z:1)
= 4.00
Calculations
Weir Coeff. Cw
= 3.10
Compute by:
Q vs Depth
No. Increments
= 50
Depth (ft)
2.00
1.50
1.00
0.50
,Q 1 1
-0.50
0 5 10 15 20 25
Weir
11113- 50 YEAR
Highlighted
Depth (ft)
Q (Cfs)
Area (sqft)
Velocity (fUs)
Top Width (ft)
Sunday, Mar 7 2021
= 1.05
= 177.98
= 56.91
= 3.13
= 58.40
Depth (ft)
2.00
1.50
1.00
0.50
0.00
-0.50
35 40 45 50 55 60 65 70 75
Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.
IIIB - 100 YEAR
Trapezoidal Weir
Crest
= Sharp
Bottom Length (ft)
= 50.00
Total Depth (ft)
= 1.50
Side Slope (z:1)
= 4.00
Calculations
Weir Coeff. Cw
= 3.10
Compute by:
Q vs Depth
No. Increments
= 50
Depth (ft)
2.00
1:50
1.00
0.50
0.00
-0.50
IIIB -100 YEAR
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (fUs)
Top Width (ft)
Sunday, Mar 7 2021
= 1.20
= 219.40
= 65.76
= 3.34
= 59.60
Depth (ft)
2.00
1.50
1.00
0.50
0.00
-0.50
U b 1U 1b 2U 25 30 35 40 45 50 55 60 65 70 75
Weir W.S. Length (ft)

Zorda, Garrett D
From: Zorda, Garrett D
Sent: Thursday, April 15, 2021 1:49 PM
To: Brian Downs; Rick Baker
Cc: Granseur Dick; Jacob Dooley; Andy Priolo - Couche Tard ([e-mail]); Hall,
Christine
Subject: RE: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8
050547) - Request for Additional Information
Good Afternoon All,
I have completed my review of the subject project and everything is almost good to go, there is just one minor thing that
I need revised before I am able to issue this modification. Section IV.10 of the application was updated to reflect the
drainage area for the Phase I&II drainage area, as requested previously, however, the BUA allocations do not appearto
match the most recent modification to SW8 050547. For example, the submitted table indicates that the "Future"
allocation for the Phase I&II area is 3,012,132 square feet. The most recent issuance, however, lists the "Future"
allocation for the Phase I&II drainage area as 2,223,812 square feet.
In order to ensure consistency, can you please provide an updated Section IV.10 of the application that includes the
correct BUA allocations for the Phase I&II drainage area per the most recent issuance approved on October 6, 2020?
That updated page can be emailed to me and I would be happy to print and slip sheet it into the application package.
Once I receive that updated page, I should have a complete package and be able to issue the modification. With that in
mind, I will go ahead and begin drafting the permit so that it will be ready to go when I receive the update application
page.
In the meantime, please let me know if you have any questions.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct —Please note the change to my direct phone number"
garreft.zorda(M ncden r.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405
_._...;'ar"�:�'1?%i.1"it:C:'iC,a'`.is,''�:_-otp t�1:-,�;1`,dres is;a.il];; if7i'�1r
r,
`1 „7 7111�c`9 t tll: iC..:CC7?[ S Lail. aV �k: disi;ilaf C© [%71E�� �xr'i .

Zorda, Garrett D
From: Zorda, Garrett D
Sent: Thursday, March 11, 2021 1:06 PM
To: Rick Baker, Granseur Dick ([e-mail]); Jacob Dooley; Priolo, Andy
Cc: Hall, Christine
Subject: RE: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8
050547) - Request for Additional Information
Good Afternoon Mr. Baker,
That proposed two week extension is acceptable from our end as long as that timeline is acceptable with the airport and
other parties involved. With that said, please ensure all of the requested information is received by March 29, 2021.
In the meantime, if you have any additional questions or concerns, please let me know.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct ' Please note the change to my direct phone number**
garrett.zordancdenr.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405
Owl
Er,l7 rorresNendence to and from th.fs address is subject to hia
h t:, Car��iina ?ubii Lati., and rna;, to to ti iti►
f�
From: Rick Baker [mailto:[e-mail]]
Sent: Thursday, March 11, 20218:45 AM
To: Zorda, Garrett D <[e-mail]>; Granseur Dick ([e-mail]) <[e-mail]>; Jacob Dooley
<[e-mail]>; Priolo, Andy <[e-mail]>
Cc: Hall, Christine <[e-mail]>
Subject: RE: [External] RE: Wilmington International Airport EDDB Circle K Modification (SW8 050547) Request for
Additional Information
CAUTION: External erra3. Co not cock links or open attach-fnents unless. you �,-Ltrify..Send all sus�iclotus emaol as an at�act'iment to
Report Spam.
Garrett,

Again, we think you and Christine for your time on the call earlier this week.
We are requesting an extension of 14 calendar days for submittal of additional information as requested in your letter
dated February 26, 2021. That would make the deadline for submittal March 29, 2021.
We appreciate your consideration of this request.
Thanks,
Rick Baker, PE
Principal/Group Leader
TlNiMONS GROUP I www.timmons.com
5410 Trinity Rd, Suite 102 1 Raleigh, NC 27607
Office:919.866.4939 1 Mobile:[phone]
Linkedin: www.linkedin/in/rick-baker/
Engineering j Design I Technology
Your Vision Achieved Through Ours
To send me files greater than 20MB click here
From: Zorda, Garrett D <[e-mail]>
Sent: Friday, March 5, 20218:51 AM
To: Rick Baker <[e-mail]>; Granseur Dick ([e-mail]) <[e-mail]>; Jacob Dooley
<[e-mail]>; Priolo, Andy <[e-mail]>
Cc: Hall, Christine <[e-mail]>
Subject: RE: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8 050547) - Request for
Additional Information
Good Morning Mr. Baker,
We are available for a teleconference meeting on Tuesday March 9, 2021 at 10:00am to discuss any questions you may
have. If this date/time works for you, please send us the meeting request so that we may join.
In the meantime, if you have any additional questions, please let me know.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct **Please note the change to my direct phone number"
garrett.zordaa ncden r.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405

J�
D_ E Q
u�ll�f w pr�gRal q��Fry
raa corresprv'.: 1 moo ! 7 -mic tf ;'s : ddres's !$ ka the
PV0!T i C>!'rleOO, i idw+lC Re 3orcis Lis_%v fir.,d r31ay t- .t��ci�� -e 'A � t i;
�- „a r, third 4_�:'tia.
From: Rick Baker <[e-mail]>
Sent: Thursday, March 4, 20215:35 PM
To: Zorda, Garrett D <[e-mail]>; Granseur Dick (gdic;;@flyiim.com) <[e-mail]>; Jacob Dooley
<[e-mail]>; Priolo, Andy <[e-mail]>
Cc: Hall, Christine <[e-mail]>
Subject: [External] RE: Wilmington International Airport EDDB - Circle K Modification (SW8 050547) - Request for
Additional Information
CAiI TO N: External Lmcl Do rvtclick ks or open atta&ments unlass you verify. Send aN sL4picious email as an attachment to
Garrett,
We have reviewed your request for additional information and are requesting a meeting (in person or via ZOOM) to
review your comments and ask for some clarification so we can respond with the information necessary to keep this
project moving forward.
We also have a question about the turn lane in the public right of way inside the airport.
Please let us know some available dates and times so we can schedule.
Thanks,
Rick Baker, PEE
Principal/Group Leader
TII!!liMONS GROUP I www.timmons.com
5410 Trinity Rd, Suite 102 I Raleigh, NC 27607
Office: 919.866.4939 I Mobile: [phone]
Linkedin: www.linkedin/in/rick-baker/
Engineering I Design I Technology
Your Vision Achieved Through Ours
To send me files greater than 20iiiiB click here
From: Zorda, Garrett D <[e-mail]>
Sent: Friday, February 26, 20214:00 PM
To: Granseur Dick ([e-mail]) <gdi::[e-mail]>; Rick Baker <Rick.Baker(@timmojis.ccm>; Jacob Dooley
<[e-mail]>; wrice rircle!r <.com
Cc: Hall, Christine <[e-mail]>

Subject: Wilmington International Airport EDDB Circle K Modification (SW8 050547) Request for Additional
Information
CAliTIC3N: This email originated frc1h outside of the oa ization. too nrl, c'ick itnks or open attachments unless you recognize the
sender and know the content is safe.
All,
Attached is a pdf of the request for additional information for the subject project. There are just a few items that need
to be addressed. Please let me know if you have any questions or concerns.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct **Please note the change to my direct phone number**
garrett.zorda(aZncdenr.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405
Ema ,' ccrrespondenc ,� to aad from, this address is subject to Z he
North Caro nna %blic Records i_a!v and may be -disclosed to third part,as.

Brian Downs
From: Jacob Dooley
Sent: Wednesday, March 3, 2021 9:01 AM
To: Brian Downs
Subject: FW: [External] RE: D-065-20-041 Circle K NTI Airport
FTI Confirmation from DOT hydro for todays discussion. Post -Flows must be less than Pre -Flows for the 10,25,50, and
100 year storms. As discussed, it seems diverting more drainage to basin IIIB is the best option.
Jacob
From: Wurzel, Joseph P<[e-mail]>
Sent: Monday, March 1, 20219:08 AM
To: Jacob Dooley <[e-mail]>
Subject: RE: [External] RE: D-065-20-041 Circle K NTI Airport
That is correct. Once we get the revised plans I will forward it to our hydro department for their review on it again.
Thank you,
Patrick Wurzel
Engineering Technician
North Carolina Department of Transportation
Division 3 District 3
910 398 9100 Office
910 398 9118 Direct
*PwurzelCa)ncdot.4ov
300 Division Drive
Wilmington, NC 28401
Email correspondence to and from this addresz is sui)ject to the
Horth Carolina Public. Records taw and may be disclo3cd to third parties.
From: Jacob Dooley <[e-mail]>
Sent: Monday, March 1, 20218:23 AM
To: Wurzel, Joseph P <[e-mail]>
Subject: RE: [External] RE: D-065-20-041 Circle K NTI Airport
LHu i ON: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
Report Snar.

Good Morning Mr. Wurzel,
We are working on revising our plans to reduce the discharges to the NCDOT right of way. lust to confirm (I know this
may seem obvious), but for DOT hydro approval we just need to reduce post condition discharges to equaVunder the
current predevelopment rates for the below storms?
Thanks,
Jacob Dooley, PE
Project Engineer III
TIMMONS GROUP I www.timmons.com
5410 Trinity Rd, Suite 102 1 Raleigh, NC 27607
Office:919.866.4937 1 Fax: [phone]
Your Vision Achieved Through Ours
To send me files greater than 20MB click here
From: Wurzel, Joseph P <[e-mail]>
Sent: Monday, February 15, 20218:39 AM
To: [man Downs <Brian.Downs @timmons.com>
Cc: Drees, Nick K <[e-mail]>
Subject: RE: [External] RE: D-065-20-041 Circle K NTI Airport
Good Morning,
The comments from hydro are:
-Water is still being diverted to NCDOT right of way, thus there should not be an increase in discharges in the 10,25,50,
and 100 year storms.
Thank you,
Patrick Wurzel
Engineering Technician
North Carolina Department of Transportation
Division 3 District 3
910 398 9100 Office
910 398 9118 Direct
Emurzel(a)_ncdot.gov
300 Division Drive
Wilmington, NC 28401

Pir,oil correspondence to end from this address is subject to the
North Carolina Public Records Law and may he disclosed to ihird parties.
From: Wurzel, Joseph P
Sent: Wednesday, December 30, 2020 9:24 AM
To: Brian Downs <Brian.Downs @timmons.com>
Subject: RE: [External] RE: D-065-20-041 Circle K NTI Airport
Good Morning,
Below are the revised hydro comments.
• Based on the proposed drainage and calculations there are diversions to the two 24" pipes under 23rd Street.
Drainage patterns need to be maintained or the post discharge at the inlet of the two 24" pipes should be equal
or less than the pre. This should be the case for the 10,25,50, and 100-year storms.
• Based on the proposed contours it would seem that the geometry of the ditch along 23'd Street is being reduced.
Please maintain existing ditch geometry with slopes 3:1 or flatter.
Thank you,
Patrick Wurzel
Engineering Technician
North Carolina Department of Transportation
Division 3 District 3
910 398 9100 Office
910 398 9118 Direct
imurzeKcbncdot.aov
300 Division Drive
Wilmington, NC 28401
Email corresnondcncs to and from this address is suhjert to the
North Carolina Pubic Rero: ds Law and maybe disclosed io third parties.
From: Brian Downs <Brian.Downs @timmons.com>
Sent: Thursday, December 10, 2020 2:22 PM
To: Wurzel, Joseph P <[e-mail]>
Subject: [External] RE: D-065-20-041 Circle K NTI Airport

CAUTION- External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
Report Spa, _.
Patrick,
I'm sending our revised plans, the DA maps, comment response, and talc information to you via the DOT FTS system.
Let me know if you have any questions,
Brian
From: Wurzel, Joseph P <ipwurzel(d)ncdot.eov>
Sent: Monday, November 16, 2020 2:45 PM
To: Brian Downs <Brian.Downs @timmons.com>
Subject: D-065-20-041 Circle K NTI Airport
FCCAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the
sender and know the content is safe.
Good Afternoon,
Below are our comments. I will also be sending the file through our FTS system. (with red line comments)
Provide a simple Pre vs Post chart showing the drainage areas and discharges approaching the right of way at
the two cross pipes under 23rd Street. It seems that due to the development some of the existing drainage
patterns/drainage areas have changed in the proposed condition for these two cross pipes. If there is a
diversion, then the Post should not exceed the Pre in the 10, 25, 50, and 100-year storms.
a Providing a drainage area map would be helpful.
Thank you,
Patrick Wurzel
Engineering Technician
North Carolina Department of Transportation
Division 3 District 3
910 398 9100 Office
910 398 9118 Direct
0pwurzelic0cdot.gov
300 Division Drive
Wilmington, NC 28401
Email rorresocndence to and from rhis address is subject if) the
'orth Carolina PuLlic Reco,-ds Law and moy be disclosed to third par&_-s.

RECEIVED
ILM
MAR 0 2 2021
NCDEQ
WILMINGTON RO
March-2, 2021
Airport Authority
Garrett Zorda
Environmental Engineer
Donna Girardot
Division of Energy, Mineral and Land Resources
Chairman
Stormwater Program, NC DEQ
Harry W. Stovall
127 Cardinal Drive Ext.
Vice Chairman
Wilmington, NC 28405
F. Spruill Thompson
Secretary
Julia Olson-Boseman
Ref: Stormwater Applicant Original Documents
Stormwater Project No. SW8 050547
Nick Rhodes
W. Lee Williams
Thomas Wolfe Dear Mr. Zorda-,
Airport Director In accordance with your preliminary comment letter dated Feb. 2611, 2021,
requesting original documents, please find attached one original copy each of the
Julie A. Wilsey, AAE application, maintenance agreement and deed restrictions & protective covenants.
Other items indicated in your letter will be addressed at a later date by the engineer
of record for this project.
If you have any comments for further requests, please do not hesitate to contact me.
Respectfully,
Granseur Dick, PE, CM
ILM Facilities Director
Cc: Brian- Downs, PE, Tian- mons Group -
Wilmington
Intemational Airport
1740 Airport Blvd., Ste. 12
Wilmington, NC 28405
910.341.4333
flyilm.com

e
5410 Trinity Road P 919.866.4951
Suite F 919.859.5663
'�' 1M M O N S GROUP
Raleigh,
NC 27607 www.liUnansoo�n
Project Name: Circle K — NTI Airport Blvd Wilmington — NC.115
Project Number: 37630.054
Project Contact: Brian Downs
Phone: [phone]
Email: brian.downs(cD-timmons.com
• Responses to review comments have been added below comment and are in bold.
Garrett Zorda, Environmental Engineer I email: [e-mail]
1. 15A NCAC 02H.1003(6) and the 2004 approved Stormwater Master Plan document:
This modification is proposing to add two dry detention basins in the area previously
approved under Phase III of the Master Plan and was to be treated in an expansion of
the existing dry detention basin. These two new dry detention basins must either meet
the requirements in the previously approved agreement from 2004 or demonstrate they
are an equal or better variation under the 2017 rules.
Response:
• This submittal is an improvement upon the previously permitted Phase III
basin expansion for the following reasons:
o The proposed design is consistent with the pre-existing drainage
patterns, and releases stormwater at discharge points, which are
consistent with the existing conditions.
o It is not practical to direct all stormwater to the previously permitted
Phase III basin expansion to.the east, due to conflicts with existing
topography, wetlands, and existing critical Airport utilities.
o The previously permitted Phase III basin expansion did not propose
new vegetated pre-treatment swaies. Our design does provide
proposed vegetated pre-treatment swaies.
o The location of the previously permitting Phase III basin expansion now
contains a jurisdictional wetland. Illustrating the SWHT levels at that
location are as high, if not higher, than our proposed SCM locations.
This submittal will provide an equivalent stormwater treatment as the
previously permitted Phase III basin expansion, in that we are providing
equivalent stormwater SCM(s), which are extended dry detention basins.
a. The inlet and outlet of the Phase IIIB extended dry detention pond appear to be
located in a manner that promotes short circuiting and does not appear to
support the minimum flow length- to -basin width ratio as required in the 2004
approved Stormwater Master Plan document for this alternative design. Please
ENGINEERING I DESIGN I TECHNOLOGY

reconsider the design such that the system will meet the minimum length to width
ratio required by the 2004 approved Stormwater Master Plan document or
demonstrate the Phase I I I B system provides equal or better treatment under the
2017 rules.
Response: We revised the low flow channel in the Phase IIIB extended dry
detention pond in order to meet the requirement of the minimum flow
length to width ratio provided in the Stormwater Master Plan document. We
are also proposing a permanent water -tight diversion dam at the same
height of the berm to further ensure no short-circuiting of inlet to out in
large storm events.
b. The 2004 approved Stormwater Master Plan document for this alternative design
indicates that the extended dry detention basins should "to the extent possible,
position the bottom of the basin above the seasonal high water table." The
proposed design appears to position the bottom of the basins below the season
high water table and provide a clay liner, however, no technical
justification/explanation was provided to support that this requirement was
considered. Please provide technical justification supporting that the position of
the bottom of the basins are above the seasonal high water table to the greatest
extent possible.
Response: We have located the basins to better maintain the existing
drainage patterns. The basin type and the limited upstream to downstream
topography difference worked in conjunction to set the basin depths. It is
not possible to raise the proposed extended dry detention basins to a
higher elevation, due to the flat topography. We already raised the basins
as high as feasible. Compared to the nearby existing basin to the east, both
proposed basins are significantly higher in elevation and are likely an
improvement as far as the SHWT. The 2004 approved Stormwater Master
Plan indicates that the basins should be above the SHWT "to the extent
possible", and we have complied with this requirement "to the extent
possible".
c. The 2004 approved Stormwater Master Plan document for this alternative design
indicates for grassed swales, that the "swale bottom should be located above the
seasonal high water table". The proposed design, however, appears to position
the bottom of the swales below the seasonal high water table. Please confirm the
intended design and ensure this requirement for the alternative design is met.
Response: Our response is the same as above. Our proposed grass
swales are significantly higher in elevation compared to the existing grass
swales to the Phase III basin to the east. Therefore, we believe we are
providing an improved SCIiiS design. Due to the shallow SHWT and the fiat
topography, we cannot raise the proposed grass swales any higher. We
are complying with this requirement "to the extent possible".

d. The 2004 approved Stormwater Master Plan document for this alternative design
indicates for grassed swales, "an attempt shall be made to provide 100 linear feet
of swale per acre of drainage area. No less than 50 linear feet of Swale per acre
shall be provided.". The provided calculations for the swales indicate that
drainage area for the Phase IIIA and Phase IIIB grassed swales are both 150
linear feet, which is less than the minimum 50 linear feet per acre. Please confirm
the intended design and ensure this requirement for the alternative design is met.
Response: One of our challenges is to retain as much developable area for
ILM as possible while improving stormwater treatment. In the available
area, coupled with the previously described SWHT challenges, it was not
possible to provide 50 LF of grassed swale per acre. Therefore, we are
providing grass swales of similar length to the approved Master Plan while
treating a much smaller drainage area. The previously approved Phase III
extended Dry Detention Basin had two 150' grassed swales treating
approximately 190 acres. We matched the length and width for
approximately 15 acres. Comparatively, we are improving proposed pre-
treatment conditions by a 12x factor.
2. 15A NCAC 02H.1003(7) and .1042(2)(k): Proposed deed restrictions and protective
covenances were provided for this project, however, offsite lots/subdivision of property
does not appear to be proposed as part of this project. Please confirm if it is intended to
subdivide this property into offsite lots and ensure it is represented consistently
throughout the entire application package. Please note, subdivided offsite lots would be
required to apply and receive approval for their own separate offsite permit.
Response: Circle K, and subsequent buildings, will utilize a land lease and we are
not proposing to subdivide any offsite lots. It is acknowledged that future offsite
developments would need to obtain their own separate permit(s) with separate
deed restrictions and protective covenants in the future (by others) if that
changes.
3. 3. 15A NCAC 02H.1042(2)(a):
a. The signatures provided on the submitted application, operation and
maintenance agreements, and proposed deed restrictions and protective
covenances were all copies. These documents must include an original
signature. Please provide an original signature for all documents that require the
applicants signature.
Response: We remain in the process of obtaining the original signed
documents and will provide upon receipt.
b. Section 111.1 and Section 111.2 lists New Hanover County Airport Authority as
lessee and property owner, respectively. As the current permittee and the entity
responsible for this modification, New Hanover County Airport Authority should
be listed in Section 111.1 as the property owner. Please update Section 111.1 and

111.2 of the application and ensure it is represented consistently throughout the
entire application package.
Response: The New Hanover County attorney instructed ILM to sign on
their behalf due to th;�� .nature of their long term lease. ILM is in the process
of obtaining a letter from the NHC to support this claim. We will provide the
letter upon receipt.
4. 15A NCAC 021-1.1042(2)(a)(iv): In order to ensure the SWU-101 form remains
consistently updated and represents the entire permitted condition, Section IV.10 of
the application must reflect all drainage areas covered in this permit. Please update
Section IV.10 of the application to reflect all drainage areas permitted under SW8
050547.
Response: Section IV.10 has been updated to reflect all drainage areas
permitted under SW8 050547.
5. 15A NCAC 02H.1042(2)(a)(iv), .1003(3)(b), and 1050(1):
a. The built -upon area (BUA) listed in Section IV.10 of the application,
supplements and calculations are not consistent. Please confirm the correct
BUA amounts for each of the two extended dry detention basins and ensure
they are represented consistently throughout the entire application package.
Response: The BUA listed in Section IV.10 is now consistent
throughout supplements and calculations package.
b. The two drainage areas for the Phase IIIA and Phase IIIB dry detention basins
proposed as part of this modification do not match the previously approved
Phase III drainage area. Please confirm one of the following and update the
application package appropriately:
Response: See below.
If the previously approved Phase III drainage area is proposed to now
be treated by the proposed Phase IIIA and Phase IIIB dry detention
basin, the application package will need to be updated to include the
entire previously approved Phase III area;
Response: Not applicable. Our proposed basins IIIA and IIIB are
proposing to treat the Phase IIIA and Phase IIIB drainage areas
only, as depicted on our maps. We are not proposing to treat
other previously permitted offsite drainage areas in our basins
IIIA and IIIB.
If the previously approved Phase III modification to EDDB #1 is still
proposed to treat the remaining Phase III area that will not drain to the
proposed Phase IIIA and Phase IIIB extended dry detention basins, the
application package will need to be revised to include this modification
to the EDDB #1 drainage area;
Response: The application has been edited to show a Phase 3C,
which is the remaining area of Phase III outside of our project
limits. We have separated impervious into existing and future, with
the future impervious being the amount allotted for future
development outside of our project limits. The impervious number
was acquired by maintaining the approved percentage (81.4%) with
the remaining Phase 3C area. The Phase 3C area was not able to be
captured due to the existing depth of critical Airport utility
infrastructure paralleling Airport Blvd.
iii. If an additional low density drainage area is proposed for the previously
approved Phase III area that is not being collected and treated by the

proposed Phase IIIA and Phase IIIB extended dry detention basins and
will no longer drain to EDDB #1, the application package will need to be
updated to reflect the additional drainage area;
Response: No low density drainage areas are proposed.
iv. if the previousiy approved Phase I II area that is not being collected and
treated by the proposed Phase IIIA and Phase I I I B extended dry
detention basins is being removed from permit number SW8 050547, a
separate, new permit application will be submitted to cover this area. In
this case, the separate permit application must be submitted with the
response to this request.
Response: A separate permit application, by others, will be
submitted in the future to treat the Phase 3C drainage area. We
were not able to capture this drainage area due to the existing
depth of critical Airport utility infrastructure paralleling Airport
Blvd. and the needed stormwater conveyance pipe depth.

� 5410 Trinity Road
T■ I M M 0 N S RCow"v�A SuitelOZ
`
YOUR VISMN ACaM%ifio T ;,,J7 S. Raleigh, NC 27607
TRANSMITTAL
NCDEQ - Christine Hall
TO:
Stormwater Department
127 Cardinal Drive Extension
Wilmington, NC 28405
P 919.866.4951
F 919.859.5663
w+Nw�immons.aam
Date: 1/20/21 Job#: 37630.054
Circle K - NTI Airport Blvd Wilmington -
Project: NC.115
Reference: Submittal #2
Copies Sent To:
COPIES .
DATE
NUMBER
DESCRIPTION
2
01/2U/2021
1
Stormwater Management Permit Application
2
01/22021..,
2
Deed Restrictions and Protective Covenants Form
1
171./Zi0021 .
` 3
SCM Supplements Forms
1
01 /20/2021
4
Detailed Narrative
1 _ ....
_.01/20/2021, ..
5- .
USGS Map- ...
1
01/20/2021
6
Calculations Package included SHWT report)
2
01/20/2021
7
Folded 24" x 36" plans
1
01/20/2021
8
Copy of Property Deed
1
01/20/2021
9
NC Secretary of State Registration - Circle K Meredith W Rice
1
01/20/2021
10
New Hanover County Authorization
1
01/20/2021
11
Agent Owner Authorization Letter
1
01/20/2021
12
O&M Agreements
1
01/20/2021
13
ILM Stormwater Master Plan
1
01/20/2021
14
Wetlands Documentation
1
01/20/2021
15
USACE 401 Permit Approval
2
01/20/2021
16
Comment Response Letter
01/20/2021
17
CD containing dfs of all documents
THESE ITEMS ARE TRANSMITTED:
!f enclosures are not as noted, please notify us at once.
COMMENTS:
RECEIVED
Thank You, JAN 21 2021
J.,
Brian Downs
Project Manager.
Timmons Group
CIVIL EVGINEERIi,IG I ENVIRO:11-404TAL I S1JPVEYI'1G I 1-4IS I LAODSCAPE ARCHITECTURE I COs`13-iRIJCTIGr, SE:"V7' .ES

Zorda. Garrett D
From: Zorda, Garrett D
Sent: Monday, January 4, 2021 12:36 PM
To: Stephen Ballentine; Granseur Dick ([e-mail])
Cc: [e-mail]; hall, Christine; Brian Downs
Subject: RE: [External] RE: Wilmington International Airport EDDB/ Circle K Modification (SW8
050547) - Request for Additional Information - Extension Request
Good Afternoon Mr. Ballentine,
The 15 day extension you mentioned is 15 calendar days, not business days, which add up to the maximum of 30 days.
As stated in the December 18, 2020 letter "Please note that only two letters requesting additional information is allowed
in the State Stormwater Program for a total of 30 days to submit the requested additional information. !f the information
is not satisfactorily provided after either the second request or 30 days, the project will be returned." Additionally, there
is another proposed modification to SW8 050547 that cannot be submitted until this modification is
issued/returned/withdrawn/etc., so it is important that the appropriate timelines are followed. With that said, I am only
able to approve an extension of 15 calendar days, with a due date of January 21, 2021. Please ensure all of the
requested information is received by this office by January 21, 2021. If additional information or time is needed beyond
this extension, this project will need to be returned to allow for the additional time necessary to provide a complete
application package.
Regarding any follow-up over the next few days, email would likely be most efficient. Due to the complex history of SW8
050547, 1 will likely need to discuss some of the details of any proposed solutions with my supervisor and/or coworkers
before being able to provide a complete response. With the Wilmington Regional Office being closed to the public and
much of the staff working partly remote, email would be the quickest way to facilitate any discussion. Of course, if a
phone call is ultimately needed, I should also be able to facilitate that.
In the meantime, please let me know if you have any additional questions or concerns.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct "Please note the change to my direct phone number""
oarrett.zorda(ftoden r.aov
127 Cardinal Drive Ext.
Wilmington, NC 28405
�V
ti •. �r� 101*
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From: Stephen Ballentine[mailto:[e-mail]]
Sent: Monday, January 4, 2021 10:31 AM
To: Zorda, Garrett D <[e-mail]>; Granseur Dick ([e-mail]) <[e-mail]>
Cc: [e-mail]; Hall, Christine <Christine. Hall@ ncdenr.gov>; Brian Downs <[e-mail]>
Subject: [External] RE: Wilmington International Airport EDDB/ Circle K Modification (SW8 050547) - Request for
Additional Information - Extension Request
CAUTION: Ec err-4 emaii. Coo not click finks or open att,I�hn� ,j,ents oni-ess you verify. Send all suspicious emaii as an attactr7rrien to
Report Spam.
Zorda
Thank you for your comments. Due to the Christmas holiday, we will need additional time in order to respond to your
comments. With the understanding that the 15 day extension is 15 business days, we request an extension to resubmit
no later than Tuesday, January 26, 2021. (If possible, we will resubmit prior to this date.)
Please reply to this email to approve the extension request.
We will need to follow up with you via phone and/or email over the next few days to discuss solutions to your
comments.
Please include Brian Downs on all future correspondence with this job. Brian is copied on this email.
Regards,
Stephen Ballentine, PE
Project Manager
TIMMONS GROUP I www.timmons.com
5410 Trinity Rd, Suite 102 1 Raleigh, NC 27607
Office: 984.255.23671 Fax: [phone]
Cell: 919.812.8887
stephen. ballentineCa.timmons.com
Your Vision Achieved Through Ours
To send me files greater than 20MB click here
From: Zorda, Garrett D <[e-mail]>
Sent: Friday, December 18, 2020 1:50 PM
To: Granseur Dick ([e-mail]) <[e-mail]>; Stephen Ballentine<[e-mail]>
Cc: [e-mail]; Hall, Christine <[e-mail]>
Subject: Wilmington International Airport EDDB/ Circle K Modification (SW8 050547) - Request for Additional
Information
AUi,Liv: This emaii originated from outside of the organization. Do not click links or open attachrner'ft+ unless you recognize the
I serrder ;irJ known the content n safe.
All,

Attached is a pdf of the request for additional information for the subject project. There are just a few items that need
to be addressed. Please let me know if you have any questions or concerns.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct ""Please note the change to my direct phone number**
oarrett.zordaD-ncdenr.aov
127 Cardinal Drive Ext.
Wilmington, NC 28405
—
C+wnon.i w vw�wwwww �1yr
Email correspondence to and fro-n this address is sub;ect to the
North Caroline. Public Records Law and may be disclosed to third paities.

RiDY COOPER,
Gammor
M[CHM S. REGAN
BRIAN WR£NK
LknTW
December 18, 2020
Via email only: edickdOlyilAcom
New Hanover County Airport Authority
Attn: Granseur Dick, Facilities Director
1740 Airport Blvd.
Wilmington, NC 28405
NORTH CAROUNA
Subject: Request for Additional Information
Stormwater Project No. SW8 050547
Wilmington International Airport EDDB
New Hanover County
Dear Mr. Dick:
The Wilmington Regional Office received and accepted a modified State Stormwater Management Permit
Application for the subject project on October 6, 2020. A preliminary in-depth review of that information has
determined that the application is not complete and that additional information is needed. To continue the review,
please provide the following additional information in a single, hard cony submittal package:
15A NCAC 02H.1003(6) and the 2004 approved Stormwater Master Plan document: This modification is
proposing to add two dry detention basins in the area previously approved under Phase III of the Master
Plan and was to be treated in an expansion of the existing dry detention basin. These two new dry
detention basins must either meet the requirements in the previously approved agreement from 2004 or
demonstrate they are an equal or better variation under the 2017 rules.
ry a� The inlet and outlet of the Phase IIIB extended dry detention pond appear to be located in a
manner that promotes short circuiting and does not appear to support the minimum flow length -
to -basin width ratio as required in the 2004 approved Stormwater Master Plan document for this
alternative design. Please reconsider the design such that the system will meet the minimum
length to width ratio required by the 2004 approved Stormwater Master Plan document or
demonstrate the Phase IIIB system provides equal or better treatment under the 2017 rules.
The 2004 approved Stormwater Master Plan document for this alternative design indicates that
the extended dry detention basins should "to the extent possible, position the bottom of the basin
above the seasonal high water table." The proposed design appears to position the bottom of the
basins below the season high water table and provide a clay liner, however, no technical
justification/explanation was provided to support that this requirement was considered. Please
provide technical justification supporting that the position of the bottom of the basins are above
the seasonal high water table to the greatest extent possible.
The 2004 approved Stormwater Master Plan document for this alternative design indicates for
grassed swales, that the "swale bottom should be located above the seasonal high water table".
The proposed design, however, appears to position the bottom of the swales below the seasonal
high water table. Please confirm the intended design and ensure this requirement for the
alternative design is met.
�. `I. The 2004 approved Stormwater Master Plan document for this alternative design indicates for
grassed swales, "an attempt shall be made to provide 100 linear feet of swale per acre of drainage
area. No less than 50 linear feet of swale per acre shall be provided.". The provided calculations
for the swales indicate that drainage area for the Phase IIIA and Phase IIIB grassed swales are
4.36 acres and 15.17 acres, respectively. The provided calculations also indicate that the length of
the Phase IIIA and Phase 111E grassed swales are both 150 linear feet, which is less than the
minimum 50 linear feet per acre. Please confirm the intended design and ensure this requirement
for the alternative design is met.
awNorth CArokm CtwrUism offimtormeritW Quaby '. Division o<` oergy. hHo[rs[and t .Resc>om
�.
Wfrn1np 1ryianal0ffkc i WCmi*wlDrive Enension I WfimbVtoaNwtht'$aikra 45
910-11%7zl

State Stormwater Permit No. SW8 050547
Page 2 of 3
1, . 15A NCAC 02H.1003(7) and .1042(2)(k): Proposed deed restrictions and protective covenances were
provided for this project, however, offsite lots/subdivision of property does not appear to be proposed as
part of this project. Please confirm if it is intended to subdivide this property into offsite lots and ensure it
is represented consistently throughout the entire application package. Please note, subdivided offsite lots
would be required to apply and receive approval for their own separate offsite permit.
3. 15? CAC 02H.1042(2)(a):
The signatures provided on the submitted application, operation and maintenance agreements,
and proposed deed restrictions and protective covenances were all copies. These documents must
include an original signature. Please provide an original signature for all documents that require
the applicants signature.
Section III.1 and Section 11I.2 lists New Hanover County Airport Authority as lessee and property
owner, respectively. As the current permittee and the entity responsible for this modification,
New Hanover County Airport Authority should be listed in Section III.1 as the property owner.
Please update Section III.1 and III.2 of the application and ensure it is represented consistently
throughout the entire application package.
15A NCAC 02H. I 042(2)(a)(iv): In order to ensure the SWU-101 form remains consistently updated and
represents the entire permitted condition, Section IV.10 of the application must reflect all drainage areas
'Cl 4 covered in this permit. Please update Section IV.10 of the application to reflect all drainage areas
'. ,c permitted under SW8 050547.
r
5. 15A NCAC 02H.1042(2)(a)(iv), .1003(3)(b), and 1050(1):
xwt - *M (a) The built -upon area (BUA) listed in Section IV.10 of the application, supplements and
calculations are not consistent. Please confirm the correct BUA amounts for each of the two
9 QC �a�yG extended dry detention basins and ensure they are represented consistently throughout the entire
•.Gh `� ll,� application package.
Ga nA \ ` The two drainage areas for the Phase IIIA and Phase IIIB dry detention basins proposed as part of
h this modification do not match the previously approved Phase III drainage area. Please confirm
one of the following and update the application package appropriately:
Nk If the previously approved Phase III drainage area is proposed to now be treated by the
proposed Phase IIIA and Phase IIIB dry detention basin, the application package will
need to be updated to include the entire previously approved Phase III area•,
If the previously approved Phase III modification to EDDB #1 is still proposed to treat
the remaining Phase III area that will not drain to the proposed Phase IIIA and Phase IIIB
extended dry detention basins, the application package will need to be revised to include
�%. .. this modification to the EDDB #1 drainage area;
\= ,� ' y•`v If an additional low density drainage area is proposed for the previously approved Phase
< 1; III area that is not being collected and treated by the proposed Phase IIIA and Phase IIIB
E extended dry detention basins and will no longer drain to EDDB #1, the application
package will need to be updated to reflect the additional drainage area;
If the previously approved Phase III area that is not being collected and treated by the
proposed Phase IIIA and Phase IIIB extended dry detention basins is being removed from
permit number SW8 050547, a separate, new permit application will be submitted to
cover this area. In this case, the separate permit application must be submitted with the
response to this request.
Please remember to confirm that any revised information is presented consistently throughout the application
documents including calculations, supplements, narrative, and plans. Please also remember to provide two hard
copies of any updated documents per 15A NCAC 02H.1042(2).
All of the requested information listed above should be received in this Office by January 5, 2021, or the
application will be returned as incomplete. If additional time is needed to submit the requested information, please
email your extension request prior to this due date to the email address provided below with a justification and a
date of when the requested information will be submitted, which shall be no later than 15 days past the original
due date. Please note that only two letters requesting additional information is allowed in the State Stormwater
Program for a total of 30 days to submit the requested additional information. If the information is not
satisfactorily provided after either the second request or 30 days, the project will be returned. If the project is
returned and you wish to re -submit later, you will need to resubmit all required items at that time, including the
application fee.
The construction of any impervious surfaces, other than a construction entrance under an approved Sedimentation
Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject to enforcement action pursuant to NCGS
143-215.6A.

State Stormwater Permit No. SW8 050547
Page 3 of 3
Please reference the State assigned project number on all correspondence. If you have any questions concerning
this matter, please feel free to call me at [phone] or email me at [e-mail].
Sincerely,
q
Garrett Zorda
Environmental Engineer
DES/gdz: \\\Stormwater\Permits & Projects\2005\050547 HD\2020 12 addinfo 050547
cc: Meredith W. Rice, Jr., Vice President, Circle K Stores, Inc.; via email: [e-mail]
Stephen Ballentine, PE, Timmons Group; via email: [e-mail]
Wilmington Regional Office Stormwater File

Zorda, Garrett D
From: Zorda, Garrett D
Sent: Friday, December 18, 2020 1:50 PM
To: Granseur Dick ([e-mail]); Stephen Ballentine
Cc: [e-mail]; Christine Hall ([e-mail])
Subject: Wilmington International Airport EDDB/ Circle K Modification (SW8 050547) - Request
for Additional Information
Attachments: 2020 12 addinfo 050547.pdf
All,
Attached is a pdf of the request for additional information for the subject proiect. There are just a few items that need
to be addressed. Please let me know if you have any questions or concerns.
Thanks,
Garrett Zorda
Environmental Engineer
Division of Energy, Mineral and Land Resources State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7343 direct 'Please note the change to my direct phone number**
Qarrett.zorda(& ncden r.Qov
127 Cardinal Drive Ext.
Wilmington, NC 28405
Email correz-mndence to and from this add: ess is subtect to the
No: ,Fl, Carolina Public Peco, ds Lavv and rn y be disclosed to thi!"d parties.

TIMINAMONS GROUP
YOUR VISION AC141EVED `( C#atOUCrH OURS.
From: 5410 Trinity Road, Suite 102
Raleigh, NC 27607
lauren.norris-heflinAtimmons.com
[phone]
To: U.S. Fish and Wildlife Service
Raleigh Field Office
P.O. Box 33726
Raleigh, NC 27636-3726
October 15, 2020
5410 Trinity Road P 919.866.4951
Suite 102 F 919.859.5663
Raleigh. NC 27607 www.timmons.com
Re: Online Project Review Request, Circle K NTI Wilmington, New Hanover County, North
Carolina.
Dear Mr. Benjamin,
We have reviewed the referenced project using the North Carolina Field Office's online project
review process and have followed all guidance and instructions in completing the review. We
completed our review on October 12, 2020 and are submitting our project review package in
accordance with the instructions for further review.
Our proposed action consists of a gas station and convenience store with associated amenities
and connections to public utilities. Development is anticipated to include the construction of an
access road across a jurisdictional relatively permanent water feature (does not constitute a
wetland or stream). At this time, no other impacts are anticipated.
The location of the project and the action area are identified on the enclosed maps (Figures 1 and
2 in Appendix C, including a USGS topographic map and aerial imagery).
The project is expected to be completed over 1 to 2-years. Construction is anticipated to take
place around mid-2021 and continue for approximately 5 to 8-months.
This project review is needed as supplement to U.S. Army Corps of Engineers consultation for
use of a Nationwide Permit due to impacts to jurisdictional waters anticipated with the proposed
road crossing. The Site and future development do not have any other federal or state
involvement.
The USFWS IPaC search for the Site (Consultation Code 04EN2000-2020-SLI-1886, Event
Code 04EN2000-2020-E-04204) identified six federally listed endangered species and eight
federally listed threatened species as potentially occurring in the vicinity of the Site: red -
cockaded woodpecker (Picoides borealis), Kemp's Ridley sea turtle (Lepidochelys kempii),
leatherback sea turtle (Dermochelys coriacea), Cooley's meadowrue (Thalictrum cooleyi),

golden sedge (Carex lutea), rough -leaved loosestrife (Lysimachia asperulaefolia), northern long-
eared bat (Myotis septentrionalis), West Indian manatee (Trichechus manatus), piping plover
(Charadrius melodus), red knot (Calidris canutus rufa), American alligator (Alligator
mississippiensis), green sea turtle (Chelonia mydas), loggerhead sea turtle (Caretta caretta), and
seabeach amaranth (Amaranthus pumilus) respectively. Additionally, the IPaC identified one
federally proposed threatened and one candidate species: Eastern black rail (Laterallus
jamaicensis ssp. jamaicensis) and magnificent ramshorn (Planorbella magnifica), respectively.
No critical habitat was identified within the project area. Additionally, per the instructions of the
Raleigh Field Office's Project Review Steps, Timmons personnel assessed the potential for
impacts to the bald eagle (Haliaeetus leucocephalus).
Furthermore, a search of the North Carolina Natural Heritage Program's (NC NHP) online
database (report ID: NCNHDE-12886) revealed a sighting of the federally endangered Atlantic
sturgeon (Acipenser oxyrinchus oxyrinchus) from September 2019 within the vicinity of the
project area. This species is not identified on the IPaC report.
The project area lacks water bodies suitable to sustain the following species: Kemp's Ridley sea
turtle, leatherback sea turtle, Atlantic sturgeon, green sea turtle or loggerhead sea turtle.
Therefore, it is the opinion of Timmons that the proposed project will have no effect on these
species and they will not be described further.
Effects to critical habitat
No critical habitat is present within the project area or a 1-mile radius
Effects to federally endangered species
The project area consists of a mixed hardwood and pine forest that is largely undisturbed and
could serve as potential foraging habitat for the red -cockaded woodpecker. However, the stand
has limited connectivity to other natural areas and is not of a sufficient size to support red -
cockaded woodpecker populations. Further, no occurrences of red -cockaded woodpecker were
observed at the time of the on -site inspection or noted in the NCNHP report as occurring in the
vicinity of the site. Therefore,. it is the opinion of Timmons Group that the project may affect, but
is not likely to adversely affect the red -cockaded woodpecker.
While the project area contains regularly maintained areas, these areas could not sustain
Cooley's meadowrue due to the extent of maintenance. Other portions of the site consist of
mature mixed hardwood -pine forests not capable of supporting Cooley's meadowrue. Further, no
occurrences of Cooley's meadowrue were noted in the NCNHP report as occurring in the
vicinity of the site. Therefore, it is the opinion of Timmons Group that the proposed project will
have no effect on Cooley's meadowrue.
A majority of the project area is intensively managed, with the rest consisting of mature mixed
hardwood -pine forest and disturbed plant communities. As a result, the project area lacks diverse
plant communities and the ecotones between them that are preferred by the golden sedge.
Further, no occurrences of golden sedge were noted in the NC NHP report as occurring in the
vicinity of the site. Therefore, it is the opinion of Timmons Group that the proposed project will
have no effect on golden sedge.

•araf���
„�' � � � � � GROUP
� � � 5410 Trinity Road P 919.866.4951
Suite 102 F 919.859.5663
YOUR VISION ACHIEVED THROUGH OURS. Raleigh. NC 27607 www.timmons.com
Following an on -site inspection, the project area was observed have sandy to loamy/clayey soils,
lacking the peaty, poorly drained soils preferred by rough -leaved loosestrife. Further, no
occurrences of rough -leaved loosestrife were noted in the NC NHP report as occurring in the
vicinity of the site. Therefore, it is the opinion of Timmons Group that the proposed project will
have no effect on rough -leaved loosestrife.
Effects to federally threatened species
The project area contains mature mixed hardwood -pine forest with suitable roosting and foraging
habitat for the northern long-eared bat (NLEB). Additionally, the NC NHP report lists a 1994
sighting of the NLEB within a 1-mile radius of the project area. However, the project is not
located within a county with known roost trees, no occurrences were observed at the time of
inspection, and no hibernacula are anticipated to be located in the surrounding area to due
existing landscape characteristics. Relying upon the findings of the 1/5/2016 Programmatic
Biological Opinion for the Final 4(d) Rule on the Northern Long -Eared Bat and Activities
Exempted from Take Prohibitions to fulfil our project -specific section 7 responsibilities, it is the
opinion of Timmons Group that the proposed project may affect, but is not likely to adversely
affect NLEB.
While the NC NHP report lists a documented sighting of the West Indian manatee within 1-mile
of the project area in 2019, there are no bodies of water within the project area that could provide
suitable habitat or support the species. Therefore, it is the opinion of Timmons Group that the
project will have no effect on the West Indian manatee.
The project lacks open, sandy beaches required for the piping plover, red knot, and seabeach
amaranth species. Further, no occurrences of piping plover, red knot, or seabeach amaranth were
noted in the NC NHP report as occurring in the vicinity of the site or at the time of inspection.
Therefore, it is the opinion of Timmons Group that the project will have no effect on piping
plover, red knot, and seabeach amaranth.
The project area contains limited aquatic features, all of small size and primarily consisting of
small wetland areas, with the largest wetland area totaling 0.14 acres. Additionally, the two 0.07
acre stormwater ponds within the southeastern portion of the site represent low -quality habitat.
Due to the absence of occurrences observed and the low quality and disconnected nature of the
aquatic features identified on -site, the proposed project is not anticipated to have an adverse
impact on the American alligator. Further, no occurrences of American alligator were noted in
the NC NHP report as occurring in the vicinity of the site. Therefore, it is the opinion of
Timmons Group that the project may affect the American alligator.
Effects to proposed federally protected and -candidate species
While wetlands were identified during an on -site inspection, the largest wetland is a 0.14 acre
forested wetland. Smaller wetlands identified featured emergent vegetation but were not the
dense marshes required by the Eastern black rail and were of relatively low -quality. Further, no

occurrences of Eastern black rail were noted in the NC NHP report as occurring in the vicinity of
the site. Therefore, it is the opinion of Timmons Group that the project will have no effect on
Eastern black rail.
A freshwater stream with slow moving and submerged vegetation is located in the southeastern
portion of the project that could serve as potential habitat for the magnificent ramshorn.
However, the project area is not located near one of the known populations of the magnificent
ramshorn, which is largely believed to be extinct in the wild. Further, aquatic on -site lack the
diverse aquatic vegetation required by the species. Therefore, it is the opinion of Timmons
Group that the project will have no effect on the magnificent ramshom.
Effects to federally protected species not identified through IPae
The Raleigh Field Office Project Review steps request that reviewers assess their projects for the
potential to impact bald eagle nests. Per the NCNHP Report, there are no occurrences of the bald
eagle or their nests at or within 1-mile of the project Site. Further, no occurrences of nests or bald
eagles were observed during the Site inspection. Therefore, any disturbance of the Site is
unlikely to disturb nesting bald eagles and no Eagle Act Permit is required.
The enclosed project review package provides the information about the species and critical
habitat considered in our review, and includes a species conclusions table identifying the
determinations.
For additional information, please contact Lauren Norris -Heflin at the email address listed above.
Sincerely,
Timmons Group
e---- LA4.-.>
Sydni Law
Environmental Technician
Lauren Norris -Heflin �_
Senior Environmental Scientist
Enclosures:
1) ENTIRE PROJECT REVIEW PACKAGE_.

APPENDICES
APPENDIX A — Self Certification :Letter
Self -Certification Letter
Project Review Checklist
Species Conclusion Table
APPENDIX B — Species Reports
Official IPaC Species Report
NCNHP Species Report
APPENDIX C - Figures
Figure 1 USGS Topographic Map
Figure 2 Aerial Map with Contours
Figure 3 Environmental Inventory Map
Figure 4 Wetlands and waters of the U.S. Delineation Map

APPENDIX A

United States Department of the Interior
FISH AND WRDL-TE SERVICE
Raleigh Field Office
P.O. Box 33726
Raleigh, NC 27636-3726
Date:10/15/2020
Self -Certification Letter
Project Name Circle K NTI/Wilmington Airport
Dear Applicant:
Thank you for using the U.S. Fish and Wildlife Service (Service) Raleigh Ecological
Services online project review process. By printing this letter in conjunction with your
project review package, you are certifying that you have completed the online project
review process for the project named above in accordance with all instructions
provided, using the best available information to reach your conclusions. This letter,
and the enclosed project review package, completes the review of your project in
accordance with the Endangered Species Act of 1973 (16 U.S.C. 1531-1544, 87 Stat.
884), as amended (ESA), and the Bald and Golden Eagle Protection Act (16 U.S.C.
668-668c, 54 Stat. 250), as amended (Eagle Act). This letter also provides
information for your project review under the National Environmental Policy Act of
1969 (P.L. 91-190, 42 U.S.C. 4321-4347, 83 Stat. 852), as amended. A copy of this
letter and the project review package must be submitted to this office for this
certification to be valid. This letter and the project review package will be maintained
in our records.
The species conclusions table in the enclosed project review package summarizes
your ESA and Eagle Act conclusions. Based on your analysis, mark all the
determinations that apply:
"no effect" determinations for proposed/listed species and/or
❑✓ proposed/designated critical habitat; and/or
" z "may affect, not likely to adversely affect" determinations for proposed/listed
species and/or proposed/designated critical habitat; and/or
"may affect, likely to adversely affect" determination for the Northern long-
eared bat (Myotis septentrionalis) and relying on the findings of the January 5,
2016, Programmatic Biological Opinion for the Final 4(d) Rule on the
Northern long-eared bat;
❑� "no Eagle Act permit required" determinations for eagles.

Applicant Page 2
We certify that use of the online project review process in strict accordance with the
instructions provided as documented in the enclosed project review package results in
reaching the appropriate determinations. Therefore, we concur with the "no effect" or
"not likely to adversely affect" determinations for proposed and listed species and
proposed and designated critical habitat; the "may affect" determination for Northern
long-eared bat; and/or the "no Eagle Act permit required" determinations for eagles.
Additional coordination with this office is not needed. Candidate species are not
legally protected pursuant to the ESA. However, the Service encourages consideration
of these species by avoiding adverse impacts to them. Please contact this office for
additional coordination if your project action area contains candidate species.
Should project plans change or if additional information on the distribution of
proposed or listed species, proposed or designated critical habitat, or bald eagles
becomes available, this determination may be reconsidered. This certification letter is
valid for 1 year. Information about the online project review process including
instructions, species information, and other information regarding project reviews
within North Carolina is available at our website http://www.fws.gov/raleigh/pp.htmi.
If you have any questions, you can write to us at RaIeigbCafyys.goy or please contact
Leigh Mann of this office at 919-856-4520, ext. 10.
Sincerely,
/s/Pete Benjamin
Pete Benjamin
Field Supervisor
Raleigh Ecological Services
Enclosures - project review package

Project Review
Checklist
Step
Item
Required
Date completed/ Notes
1 and
Official Species List from IPaC
09/16/2020
2
(will include map showing the
Yes
action area)
NCDENER-Heritage Program
09/16/2020
3
database results or correspon-
If Applicable
dence.
4
Habitat Assessments or Species
If Applicable
10/12/2020
Surveys
6
Bald Eagle Conclusion Table
Yes
09/17/2020
7
NLEB
Yes
09/17/2020
8
Species Conclusion Table
Yes
10/12/2020
Online project review request
10/12/2020
9
letter or Online project review
Yes
certification letter
10
Other documentation to support
If Applicable
10/12/2020
your conclusions
Instructions
Submit project review packages electronically to Raleigh@fws.
gov. Please indicate in your email subject title if you are submit-
ting a "Review Request Letter" or a "Self -Certification Letter."
All project reviews will receive a return receipt to inform you
that your project has been successfully submitted to this office.
Please note that any single email, including attachments, must
be smaller than 25 MB. If a single email would be larger than
25 MB, please spread out multiple attachments among several
emails (use the same subject name and project reference in all
emails related to an individual project). If this is not practical,
please mail a hard copy or DVD containing the project review
package to our office:
Raleigh Field Office
P.O. Box 33726
Raleigh, NC 27636-3726
Maintain a complete copy of the project review package
in your files since it will become an integral part of your official
record of compliance.
Contact its
If you have qucstions or
comments concerning this
process, please contact
Leigh Mann at (919)
856-4520 extension 10 or
via email at
[e-mail].
http://Ralaigh.fws.gov
Federal Relay Service
for the deaf and hard -of -hearing
1 800/877 8339
U.S. Fish and Wildlife Service
http://www.fws.gov
1800/344 WILD
January 2017

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APPENDIX B

United States Department of the Interior
FISH AND WILDLIFE SERVICE
�d Raleigh Ecological Services Field Office�.�
Post Office Box 33726
Raleigh, NC 27636-3726
Phone: [phone] Fax: [phone]
In Reply Refer To: September 16, 2020
Consultation Code: 04EN2000-2020-SLI-1886
Event Code: 04EN2000-2020-E-04204
Project Name: Circle K ILM
Subject: List of threatened and endangered species that may occur in your proposed project
location, and/or may be affected by your proposed project
To Whom It May Concern:
The species list generated pursuant to the information you provided identifies threatened,
endangered, proposed and candidate species, as well as proposed and final designated critical
habitat, that may occur within the boundary of your proposed project and/or may be affected by
your proposed project. The species list fulfills the requirements of the U.S. Fish and Wildlife
Service (Service) under section 7(c) of the Endangered Species Act (Act) of 1973, as amended
(16 U.S.C. 1531 et seq.).
New information based on updated surveys, changes in the abundance and distribution of
species, changed habitat conditions, or other factors could change this list. Please feel free to
contact us if you need more current information or assistance regarding the potential impacts to
federally proposed, listed, and candidate species and federally designated and proposed critical
habitat. Please note that under 50 CFR 402.12(e) of the regulations implementing section 7 of the
Act, the accuracy of this species list should be verified after 90 days. This verification can be
completed formally or informally as desired. The Service recommends that verification be
completed by visiting the ECOS-IPaC website at regular intervals during project planning and
implementation for updates to species lists and information. An updated list may be requested
through the ECOS-IPaC system by completing the same process used to receive the enclosed list.
Section 7 of the Act requires that all federal agencies (or their designated non-federal
representative), in consultation with the Service, insure that any action federally authorized,
funded, or carried out by such agencies is not likely to jeopardize the continued existence of any
federally -listed endangered or threatened species. A biological assessment or evaluation may be
prepared to fulfill that requirement and in determining whether additional consultation with the
Service is necessary. In addition to the federally -protected species list, information on the
species' life histories and habitats and information on completing a biological assessment or

09116/2020 Event Code: CAPA2000-2020-E-04204
evaluation and can be found on our web page at http://www.fws.gov/raleigh. Please check the
web site often for updated information or changes
If your project contains suitable habitat for any of the federally -listed species known to be
present within the county where your project occurs, the proposed action has the potential to
adversely affect those species. As such, we recommend that surveys be conducted to determine
the species' presence or absence within the project area. The use of North Carolina Natural
Heritage program data should not be substituted for actual field surveys.
If you determine that the proposed action may affect (i.e., likely to adversely affect or not likely
to adversely affect) a federally -protected species, you should notify this office with your
determination, the results of your surveys, survey methodologies, and an analysis of the effects
of the action on listed species, including consideration of direct, indirect, and cumulative effects,
before conducting any activities that might affect the species. If you determine that the proposed
action will have no effect (i.e., no beneficial or adverse, direct or indirect effect) on federally
listed species, then you are not required to contact our office for concurrence (unless an
Environmental Impact Statement is prepared). However, you should maintain a complete record
of the assessment, including steps leading to your determination of effect, the qualified personnel
conducting the assessment, habitat conditions, site photographs, and any other related articles.
Please be aware that bald and golden eagles are protected under the Bald and Golden Eagle
Protection Act (16 U.S.C. 668 et seq.), and projects affecting these species may require
development of an eagle conservation plan (http://www.fws.gov/windenergy/
eagle_guidance.html). Additionally, wind energy projects should follow the wind energy
guidelines (http://www.fws.gov/windenergyn for minimizing impacts to migratory birds and
bats.
Guidance for minimizing impacts to migratory birds for projects including communications
towers (e.g., cellular, digital television, radio, and emergency broadcast) can be found at: http://
www.fws.gov/migratorybirds/`CurrentBirdlssues/Hazards/towers/towers.htm; http://
www.towerkill.com; and http://www.fws.gov/migrat=birds/CurrentBirdlssues/Hazards/towers/
comtow.html.
Not all Threatened and Endangered Species that occur in North Carolina are subject to section 7
consultation with the U.S Fish and Wildlife Service. Atlantic and shortnose sturgeon, sea
turtles,when in the water, and certain marine mammals are under purview of the National Marine
Fisheries Service. If your project occurs in marine, estuarine, or coastal river systems you should
also contact the National Marine Fisheries Service, http://www.nmfs.noaa.gov/
We appreciate your concern for threatened and endangered species. The Service encourages
Federal agencies to include conservation of threatened and endangered species into their project
planning to further the purposes of the Act. Please include the Consultation Tracking Number in
the header of this letter with any request for consultation or correspondence about your project
that you submit to our office. If you have any questions or comments, please contact John Ellis
of this office at [e-mail].

0911ut2020 Event Code: 04EN200C-2020-E-04,204
Attachment(s):
■ Official Species List

09t1.612020 Event Code: 04EN2600-2020-E-04204
Official Species List
This list is provided pursuant to Section 7 of the Endangered Species Act, and fulfills the
requirement for Federal agencies to "request of the Secretary of the Interior information whether
any species which is listed or proposed to be listed may be present in the area of a proposed
action".
This species list is provided by:
Raleigh Ecological Services Field Office
Post Office Box 33726
Raleigh, NC 27636-3726
[phone]

09/1E?2020 Even. Cr) 04EN2000-2020-E-04204 2
Project Summary
Consultation Code: 04EN2000-2020-SLI-1886
Event Code: 04EN2000-2020-E-04204
Project Name: Circle K ILM
Project Type: DEVELOPMENT
Project Description: New Circle K location.
Project Location:
Approximate location of the project can be viewed in Google Maps: https:
www.google.com/maps/Tlace/34.26665991900006N77.91823489443709W
c•Yre:�!t t:•
r'f97,.
Counties: New Hanover, NC

09;A6/2020 Evert Code: 04EW2000-2020-E-04204
Endangered Species Act Species
There is a total of 16 threatened, endangered, or candidate species on this species list.
Species on this list should be considered in an effects analysis for your project and could include
species that exist in another geographic area. For example, certain fish may appear on the species
list because a project could affect downstream species.
IPaC does not display listed species or critical habitats under the sole jurisdiction of NOAA
Fisheries!, as USFWS does not have the authority to speak on behalf of NOAA and the
Department of Commerce.
See the "Critical habitats" section below for those critical habitats that lie wholly or partially
within your project area under this office's jurisdiction. Please contact the designated FWS office
if you have questions.
1. NOAA Fisheries, also known as the National Marine Fisheries Service (NMFS), is an
office of the National Oceanic and Atmospheric Administration within the Department of
Commerce.
Mammals
NAML STATUS
Northern Long-eared Bat Myotis septentrionalis Threatened
No critical habitat has been designated for this species.
Species profile: htWs://ecos.fws.govov/ecp/s/species/9045
West Indian Manatee Trichechus manatus Threatened
There is final critical habitat for this species. Your location is outside the critical habitat.
This species is also protected by the Marine Mammal Protection Act, and may have additional
consultation requirements.
Species profile: htWs://ecos.fws.gov/ecp/Species/4469

09116/2020 Event Code: 04Ei 2000-2020-E-04204
Birds
NAME
Eastern Black Rail Laterallus jamaicensis ssp. jamaicensis
No critical habitat has been designated for this species.
Species profile: has://ecos.fws.gov/ecp/snecies/10477
Piping Plover Charadrius melodus
Population: [Atlantic Coast and Northern Great Plains populations] - Wherever found, except
those areas where listed as endangered.
There is final critical habitat for this species. Your location is outside the critical habitat.
Species profile: htWs://ecos.fws.gov/ecp/species/6039
Red Knot Calidris canutus rufa
No critical habitat has been designated for this species.
Species profile: hUs://ecos.fws.gov/ecp/species/1864
Red -cockaded Woodpecker Picoides borealis
No critical habitat has been designated for this species.
Species profile: https://ecas.fws. ov/ecp/species/7614
Reptiles
NAME
American Alligator Alligator mississippiensis
No critical habitat has been designated for this species.
Species profile: htWs://ecos.fws.gov/ecp/sl2ecies/776
Green Sea Turtle Chelonia mydas
Population: North Atlantic DPS
There is final critical habitat for this species. Your location is outside the critical habitat.
Species profile: htWs://ecos.fws.p-ov/eo/speci.es/6199
Kemp's Ridley Sea Turtle Lepidochelys kempii
There is proposed critical habitat for this species. The location of the critical habitat is not
available.
Species profile: hgps://ecos.fws.gov/ecp/species/5523
Leatherback Sea Turtle Dermochelys coriacea
`There is final critical habitat for this species. Your location is outside the critical habitat.
Species profile: https://ecos.fws.pov/ecp/Species/1493
Loggerhead Sea Turtle Caretta caretta
Population: Northwest Atlantic Ocean DPS
i here is final critical habitat for this species. Your location is outside the critical habitat.
Species profile: haps://ecos.fws.gov/ecp/species/1110
STATUS
Proposed
Threatened
Threatened
Threatened
Endangered
STATUS
Similarity of
Appearance
(Threatened)
Threatened
Endangered
Endangered
Threatened
4

09/16/2020 Event Code: 0 ?EM2000-2020-E-04204 5
Snails
NAME STATUS
Magnificent Ramshorn Planorbella magnifica Candidate
No critical habitat has been designated for this species.
Species profile: https://ecos.fws. ov/ecp/species/6216
Flowering Plants
NAME STATUS
Cooley's Meadowrue Thalictrum cooleyi Endangered
No critical habitat has been designated for this species.
Species profile: https://ecos.fws.gov/ecp/species/3281
Golden Sedge Carex iutea Endangered
There is final critical habitat for this species. Your location is outside the critical habitat.
Species profile: https://ecos.fws.gov/ecp/sl2ecies/6025
Rough -leaved Loosestrife Lysimachia asperulaefolia Endangered
No critical habitat has been designated for this species.
Species profile: https://ecos.fws.gov/ecp/species/2747
Seabeach Amaranth Amaranthus pumilus Threatened
No critical habitat has been designated for this species.
Species profile: https://ecos.fws.gov/ecp/Species/8549
Critical habitats
THERE ARE NO CRITICAL HABITATS WITHIN YOUR PROJECT AREA UNDER THIS OFFICE'S
JURISDICTION.

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Natural Heritage Element OccurrE
Element Occurrences Documented Within a One -mile F
Group
Freshwater Fish38937
Acipenser oxyrinchus
Atlantic
oxyrinchus
Mammal
24390
Corynorhinus
Easterr
rafinesquii macrotis
Mammal
32126
Myotis septentrionalis
Northe
Bat
Mammal
17664
Trichechus manatus
West Ir
Vascular Plant
30852
Baccharis
Silverlir
glomeruliflora
Vascular Plant
22454
Dichanthelium
Hidden
cryptanthum
Witchg
Vascular Plant
19327
Ptilimnium ahlesii
Carolin
Natural Areas Documented Within a One -mile Radius o
aFM
Northeast Cape Fear River Floodplain R1
Managed Areas Documented Within a One -mile Radius
.. r.
NC Department of Transportation Mitigation Site NC
NC Department of Transportation Mitigation Site NC
NC Department of Transportation Mitigation Site INC
NC Department of Transportation Mitigation Site NC
Definitions and an explanation of status designations and codes can k
Please resubmit your information request if more than one year elaps

September 16. 2020
❑ Project Boundary
Buffered Project Boundary
NHP Natural Area (NHNA)
Managed Area (MAREA)

APPENDIX C

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CIRCLE K NTI AIRPORT
WZ101 HANOVER COW TY, NORTH CAROLIN'A TIMMONS GROUP
FIGURE 1: VICINITY MAP YOUR VISION ACHIEVED THROUCH OUks. a
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ILAWUDE:34.266784 WATERSHED(SYNORTHEAST CAPE FEAR (CAPE FEAR RIVER BASIN)
LONGITUDE:-77.916195 HYDROLOGIC UNIT CODE(S)-03030007
These plans ap.! -sodlated doc:tirnants M the ekdusive P'P'rty ofTIMMONS GROUP and may not be reprodumd inw.oleormn pan and Shall not bo used fm any purpose whatsoever, indwl. but not
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Frorn: Granseur Dick <[e-mail]>
Sent: Friday, September 18, 2020 3:21 PM
To: Brian Downs <[e-mail]>
Cc: Andy Priolo - Couche Tard ([e-mail]) <[e-mail]>; Stephen Ballentine
<[e-mail]>; Carol LeTellier <[e-mail]>
Subject: RE: CK airport - layout & stockpile
Brian,
See attached for ali forms.
After the County Manager reviewed, they felt that it was more appropriate to authorize ILM, as a long term lease holder,
to execute these forms. Essentially, the County has entrusted the Authority/ Airport to manage the property as a
"perpetual" lease holder, where development more directly affects operations to the airport than the County itself. I
have attached a letter of authorization signed by the Deputy County Manager for your use if required by any of the
permitting agencies.
Thanks,
Granseur Dick, P.E., C.1/i
Irf'I L
o: 910-341-4333 x1016
e: [e-mail]
1 Facilities Director
We.4 awn o ~ Cw'kn t
3 C'^ $ a,rc, n s
Jry nti C: �I�x �C
nU-ALA.
n
OCT 0 7 2020
By.

STATE OF NORTH CAROLINA
AUTHORIZATION AND DELEGATION
NEW HANOVER COUNTY
The undersigned property owner, New Hanover County, acting through its Deputy County
Manager, hereby authorizes and delegates the New Hanover County Airport Director of her
designee to execute permits, authorizations, and covenants, and other instruments necessary for
site development specific to the premises designed as Airport Boulevard under sublease for a
Circle K rental facility, including, but not limited to, New Hanover County and State DENR
stormwater permits, U.S. Corps of Engineer permits, and covenants.
This the 10 . day of Sc�6.� 2020.
NEW HANOVER COUNTY
By:
OCT 0 % 2020
BY.--__ E. o

U.S. ARMY CORPS OF ENGINEERS
WILMINGTON DISTRICT
Action Id. SAW-2010-01904 County: New Hanover U.S.G.S. Quad: Wilmington
NOTIFICATION OF JURISDICTIONAL DETERMINATION
Property Owner/Agent: Wilmington Airport Authority
C/o Mr. Jon RosboroV& Airport Director
Address: 1740 Airport Boulevard, Suite 12
Wilmineton. North Carolina 28405
Telephone No.: [phone]
Property description:
Size (acres) 447
Nearest Waterway Smith Creek
USGS HUC 03030007
Nearest Town Wilmington
River Basin Cape Fear
Coordinates N 34-273142, W .77.916436
Location description The area being verified is the west portion of the Wilmington International Airport. located along,
23rd Street and Blue Clay Road, Wilmington New Hanover County North Carolina
Indicate Which of the Following Alp&:
A. Preliminary Determination
Based on preliminary information, there may be wetlands on the above described property. We strongly suggest you have this
property inspected to determine the extent of Department of the Army (DA) jurisdiction. To be considered final, a jurisdictional
determination must be verified by the Corps. This preliminary determination is not an appealable action under the Regulatory
Program Administrative Appeal Process (Reference 33 CFR Part 331).
B. Approved Determination
X
There are Navigable Waters of the United States within the above described property subject to the permit requirements of
Section 10 of the Rivers and Harbors Act and Section 404 of the Clean Water Act. Unless there is a change in the law or our
published regulations, this determination may be relied upon for a period not to exceed five years from the date of this
notification.
regulations, this determination may be retied upon for a period not to exceed five Years from the date of this notification
We strongly suggest you have the wetlands on your property delineated. Due to the size of your property and/or our present
workload, the Corps may not be able to accomplish this wetland delineation in a timely manner. For a more timely delineation,
you may wish to obtain a consultant. To be considered final, any delineation must be verified by the Corps,
_ The waters of the U.S. including wetland on your property have been delineated and the delineation has been verified by the
Corps. We strongly suggest you have this delineation surveyed. Upon completion, this survey should be reviewed and verified
by the Corps. ' Once verified, this survey will provide an accurate depiction of all areas subject to CWA jurisdiction on your
property which, provided there is no change in the law or our published regulations, may be relied upon for a period not to exceed
five years.
X The waters of the U.S. including wetlands have been delineated and surveyed and are accurately depicted on the plat
signed by the Corps Regnhitory Official identified below on 12/21/2010 Unless there is a change in the law or our
published regulations. this determination may be relied upon for a period not to exceed five years from the date of this
notification.
There are no waters of the U.S., to include wetlands, present on the above described property which are subject to the permit
requirements of Section.404 of the Clean Water Act (33 USC 1344). Unless there is a change in the law or our published
regulations, this determination may be relied upon for a period not to exceed five years from the date of this notification,

X The property is located in one of the 20 Coastal Counties sablect to regulation under the Coastal Area Management Act
(CAMA), You should contact the Division of Coastal Management in Wilmington NC at (910) M:7-2-15 to determine,
their requirements.
Placement of dredged or fill material within waters of the US and/or wetlands without a Department of the Army permit may
constitute a violation of Section 301 of the Clean Water Act (33 USC § 1311). If you have any questions regarding this determination
and/or the Corps regulatory program, please contact Emily Hughes at 910-251-4635.
C. Basis For Determination
This site exhibits wetland criteria as described in the 1987 Corps Wetland Delineation Manual and is adiacent to an unnamed
tributaa to Smith Creek. This site also contains a waterbody that exhibits an ordinary high water mark and is an unnamed
tributary to Smith Creek. This determination is based on information submitted by Withers and Ravenel and a site visit by
Emily Hughes on 11/10/2010.
D. Remarks
E. Appeals Informattion (This information applies only to approved jurisdictional determinations as indicated in B.
above)
This correspondence constitutes an approved jurisdictional determination for the above described site. If you object to this
determination, you may request an administrative appeal under Corps regulations at 33 CFR part 331. Enclosed you will find a
Notification of Appeal Process (NAP) fact sheet and request for appeal (RFA) form. If you request to appeal this determination you
must submit a completed RFA form to the following address:
District Engineer, Wilmington Regulatory Division
Attn: Emily Hughes, Project Manager,
Wilmington Regulatory Field Office
69 Darlington Ave.
Wilmington, North Carolina 28403-1398
In order for an RFA to be accepted by the Corps, the Corps must determine that it is complete, that it meets the criteria for appeal
under 33 CFR part 331.5, and that it has been received by the District Office within 60 days of the date of the NAP. Should you
decide to submit an RFA form, it must be received at the above address by Z/21/2011.
**It is not necessary to submRFA form to th District Office if you do not object to the determination in this correspondence.**
h
Corps Regulatory Official:
Date December 11, 2010 0 Expiration Date December 21, 2015
Action Id. SA•*/-2010-01904
The Wilmington District is committed to providing the highest level of support to the public. To help us ensure we continue to do so,
Please complete the Customer Satisfaction Survey located at our website at httu:1/reaulatorv.usacesurvev com/ to complete the survey
online.
Copy furnished:
Withers & Ravenel Attn: Troy Beasley, 1410 Commonwealth Dr Ste 101 Wilmington NC 28403

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U.S. ARMY CORPS OF ENGINEERS
WILMINGTON DISTRICT
Action Id. SAW-2019-01981 County: New Hanover U.S.G.S. Quad: NC- Castle Havne
NOTIFICATION OF JURISDICTIONAL DETERMINATION
Requestor: New Hanover County Airport Authority Agent: Timmons Group
Granseur Dick Robin Perez
1740 Airport Blvd 5410 Trinity Road
Suite 12 Suite 102
Wilmington, NC 28405 Raleigh, NC 27607
Size (acres) 37.8
Nearest Waterway Smith Creek
USGS HUC 03030007
Nearest Town Wilmington
River Basin Cape Fear
Coordinates Latitude:34.266784
Longitude:-77.916195
Location description: Proiect area is located southeast of the intersection of Airport Boulevard and N 23rd Street in
Wilmington, New .Hanover County, North Carolina
Indicate Which of the Following Apply:
A. Preliminary Determination
® There appear to be waters, including wetlands on the above described project area/property, that may be subject to Section 404
of the Clean Water Act (CWA)(33 USC § 1344) and/or Section 10 of the Rivers and Harbors Act (RHA) (33 USC § 403). The
waters, including wetlands have been delineated, and the delineation has been verified by the Corps to be sufficiently accurate
and reliable. The approximate boundaries of these waters are shown on the enclosed delineation map dated 9/23/2019. Therefore
this preliminary jurisdiction determination may be used in the permit evaluation process, including determining compensatory
mitigation. For purposes of computation of impacts, compensatory mitigation requirements, and other resource protection
measures, a permit decision made on the basis of a preliminary JD will treat all waters and wetlands that would be affected in any
way by the permitted activity on the site as if they are jurisdictional waters of the U.S. This preliminary determination is not an
appealable action undcr the Regulatory Program Administrative Appeal Process (Reference 33 CFR Part 331). However, you may
request an approved JD, which is an appealable action, by contacting the Corps district for further instruction.
❑ There appear to be waters, including wetlands on the above described project area/property, that may be subject to Section 404
of the Clean Water Act (CWA)(33 USC § 1344) and/or Section 10 of the Rivers and Harbors Act (RHA) (33 USC § 403).
However, since the waters, including wetlands have not been properly delineated, this preliminary jurisdiction determination
may not be used in the permit evaluation process. Without a verified wetland delineation, this preliminary determination is
merely an effective presumption of CWA/RHA jurisdiction over all of the waters, including wetlands at the project area, which
is not sufficiently accurate and reliable to support an enforceable permit decision. We recommend that you have the waters,
including wetlands on your project area/property delineated. As the Corps may not be able to accomplish this wetland
delineation in a timely manner, you may wish to obtain a consultant to conduct a delineation that can be verified by the Corps.
B. Approved Determination
❑ There are Navigable Waters of the United States within the above described project area/property subject to the permit
requirements of Section 10 of the Rivers and Harbors Act (RHA) (33 USC § 403) and Section 404 of the Clean Water Act
(CWA)(33 USC § 1344). Unless there is a change in law or our published regulations, this determination may be relied upon for
a period not to exceed five years from the date of this notification.
❑ There are waters, including wetlandson the above described project area/property subject to the permit requirements of Section
404 of the Clean Water Act (CWA) (33 USC § 1344). Unless there is a change in the law or our published regulations, this
determination may be relied upon for a period not to exceed five years from the date of this notification.
❑ We recommend you have the waters, including wetlands on your project area/property delineated. As the Corps may not be
able to accomplish this wetland delineation in a timely manner, you may wish to obtain a consultant to conduct a delineation that
can be verified by the Corps.
❑ The waters, including wetlands on your project area/property have been delineated and the delineation has been verified by
the Corps. The approximate boundaries of these waters are shown on the enclosed delineation map dated DATE. We strongly

SAW-2019-01981
suggest you have this delineation surveyed. Upon completion, this survey should be reviewed and verified by the Corps. Once
verified, this survey will provide an accurate depiction of all areas subject to CWA jurisdiction on your property which, provided
there is no change in the law or our published regulations, may be relied upon for a period not to exceed five years.
❑ The waters, including wetlands have been delineated and surveyed and are accurately depicted on the plat signed by the
Corps Regulatory Official identified below onDATE. Unless there is a change in the law or our published regulations, this
determination may be relied upon for a period not to exceed five years from the date of this notification.
❑ There are no waters of the U.S., to include wetlands, present on the above described project area/property which are subject to the
permit requirements of Section 404 of the Clean Water Act (33 USC 1344). Unless there is a change in the law or our published
regulations, this determination may be relied upon for a period not to exceed five years from the date of this notification.
® The property is located in one of the 20 Coastal Counties subject to regulation under the Coastal Area Management Act (CAMA).
You should contact the Division of Coastal Management in in Wilmington, NC, at (9.10) 796-7215 to determine their
requirements.
Placement of dredged or fill material within waters of the US, including wetlands, without a Department of the Army permit may
constitute a violation of Section 301 of the Clean Water Act (33 USC § 1311). Placement of dredged or fill material, construction or
placement of structures, or work within navigable waters of the United States without a Department of the Army permit may
constitute a violation of Sections 9 and/or 10 of the Rivers and Harbors Act (33 USC § 401 and/or 403). If you have any questions
regarding this determination and/or the Corps regulatory program, please contact Rachel Cayito at (910)-251-4487 or
Rachel.A.Cayito(a,usace.armv.mil.
C. Basis For Determination: Basis For Determination: See the preliminary Jurisdictional determination
form dated 1/31/2020.
D. Remarks: None.
E. Attention USDA Program Participants
This delineation/determination has been conducted to identify the limits of Corps' Clean Water Act jurisdiction for the particular site
identified in this request. The delineation/determination may not be valid for the wetland conservation provisions of the Food Security
Act of 1985. If you or your tenant are USDA Program participants, or anticipate participation in USDA programs, you should request
a certified wetland determination from the local office of the Natural Resources Conservation Service, prior to starting work.
F. Appeals Information (This information applies only to approved jurisdictional determinations as indicated in B.
above)
This correspondence constitutes an approved jurisdictional determination for the above described site. If you object to this
determination, you may request an administrative appeal under Corps regulations at 33 CFR Part 331. Enclosed you will find a
Notification of Appeal Process (NAP) fact sheet and request for appeal (RFA) form. If you request to appeal this determination you
must submit a completed RFA form to the following address:
US Army Corps of Engineers
South Atlantic Division
Attn: Phillip Shannin, Review Officer
60 Forsyth Street SW, Room 1OM15
Atlanta, Georgia 30303-8801
In order for an RFA to be accepted by the Corps, the Corps must determine that it is complete, that it meets the criteria for appeal
under 33 CFR part 331.5, and that it has been received by the Division Office within 60 days of the date of the NAP. Should you
decide to submit an RFA fora_, it must be received at the above address by Not applicable.
**It is not necessary to submit an RFA form to the Division Office if you do not object to the determination in this correspondence.**
CAPITOXACHEL.ANN, moanysionedny
Corps Regulatory Official: 1536276790 fMROAACHELANN.1536276790Date 2020.01.3111-36:11-05'00'
Date of JD: 1/31/2020 Expiration Date of JD: Not applicable

NOTIFICATION OF ADMINISTRATIVE APPEAL OPTIONS AND PROCESS AND
REQUEST FOR APPEAL
Applicant: New Hanover County Airport Authority,
File Number: SAW-2019-01981
Date: 1/31/2020
Granseur Dick
Attached is:
See Section below
❑
INITIAL PROFFERED PERMIT Standard Permit or Letter ofpermission)
A
❑
PROFFERED PERMIT Standard Permit or Letter ofpermission)
B
PERMIT DENIAL
C
Li
APPROVED JURISDICTIONAL DETERMINATION
D
ZI
PRELIMINARY JURISDICTIONAL DETERMINATION
E
SECTION 1- The following identities your rights and options regarding an administrative appeal of the above decision.
Additional information may be found at or htlo://www-usacc-army.mi1.!NFissi.ons,'CiviItiVorksiRrp-ulatoPrL)PramandPcrmiis,aspx
or the Corps regulations at 33 CFP fact 331.
A: INITIAL PROFFERED PERMIT: You may accept or object to the permit.
• ACCEPT: If you received a Standard Permit, you may sign the permit document and return it to the district engineer for final
authorization. If you received a Letter of Permission (LOP), you may accept the LOP and your work is authorized. Your
signature on the Standard Permit or acceptance of the LOP means that you accept the permit in its entirety, and waive all
rights to appeal the permit, including its terms and conditions, and approved jurisdictional determinations associated with the
permit.
• OBJECT: If you object to the permit (Standard or LOP) because of certain terms and conditions therein, you may request
that the permit be modified accordingly. You must complete Section II of this form and return the form to the district
engineer. Your objections must be received by the district engineer within 60 days of the date of this notice, or you will
forfeit your right to appeal the permit in the future. Upon receipt of your letter, the district engineer will evaluate your
objections and may: (a) modify the permit to address all of your concerns, (b) modify the permit to address some of your
objections, or (c) not modify the permit having determined that the permit should be issued as previously written. After
evaluating your objections, the district engineer will send you a proffered permit for your reconsideration, as indicated in
Section B below.
B: PROFFERED PERMIT: You may accept or appeal the permit
• ACCEPT: If you received a Standard Permit, you may sign the permit document and return it to the district engineer for final
authorization. If you received a Letter of Permission (LOP), you may accept the LOP and your work is authorized. Your
signature on the Standard Permit or acceptance of the LOP means that you accept the permit in its entirety, and waive all
rights to appeal the permit, including its terms and conditions, and approved jurisdictional determinations associated with the
permit.
• APPEAL: If you choose to decline the proffered permit (Standard or LOP) because of certain terms and conditions therein,
you may appeal the declined permit under the Corps of Engineers Administrative Appeal Process by completing Section II of
this form and sending the form to the division engineer. This form must be received by the division engineer within 60 days
of the date of this notice.
C: PERMIT DENIAL: You may appeal the denial of a permit under the Corps of Engineers Administrative Appeal Process by
completing Section 11 of this form and sending the form to the division engineer. This form must be received by the division
engineer within 60 days of the date of this notice.
D: APPROVED JURISDICTIONAL DETERMINATION: You may accept or appeal the approved JD or provide new
information.
• ACCEPT: You do not need to notify the Corps to accept an approved JD. Failure to notify the Corps within 60 days of the
date of this notice, means that you accept the approved JD in its entirety, and waive all rights to appeal the approved JD.
• APPEAL: If you disagree with the approved JD, you may appeal the approved JD under the Corps of Engineers
Administrative Appeal Process by completing Section 11 of this form and sending the form to the district engineer. This form
must be received by the division engineer within 60 days of the date of this notice.

E: PRELIMINARY JURISDICTIONAL DETERMINATION: You do not need to respond to the Corps regarding the
preliminary JD. The Preliminary JD is not appealable. If you wish, you may request an approved JD (which may be appealed),
by contacting the Corps district for further instruction. Also you may provide new information for further consideration by the
Corps to reevaluate the JD.
ECTtON II. - RFQUFST FOR APPEAL or OBJEC'NOWS TO AN. INITIAL PROFFERED_ PERMIT_
REASONS FOR APPEAL OR OBJECTIONS: (Describe your reasons for appealing the decision or your objections to an initial
proffered permit in clear concise statements. You may attach additional information to this form to clarify where your reasons or
objections are addressed in the administrative record.)
ADDITIONAL INFORMATION: The appeal is limited to a review of the administrative record, the Corps memorandum for the
record of the appeal conference or meeting, and any supplemental information that the review officer has determined is needed to
clarify the administrative record. Neither the appellant nor the Corps may add new information or analyses to the record.
However, you may provide additional information to clarify the location of information that is already in the administrative
record.
FOF1 "i' OI= C0INTAC: i' FOR < LEI STIONS OR, INFOW 1ATIUN-
If you have questions regarding this decision and/or the
If you only have questions regarding the appeal process you may
appeal process you may contact:
also contact:
District Engineer, Wilmington Regulatory Division
Mr. Phillip Shannin, Administrative Appeal Review Officer
Attn: Rachel Capito
CESAD-PDO
Wilmington Regulatory Office
U.S. Army Corps of Engineers, South Atlantic Division
U.S Army Corps of Engineers
60 Forsyth Street, Room 1OM15
69 Darlington Avenue
Atlanta, Georgia 30303-8801
Wilmington, North Carolina 28403
Phone: [phone]
RIGHT OF ENTRY: Your signature below grants the right of entry to Corps of Engineers personnel, and any government
consultants, to conduct investigations of the project site during the course of the appeal process. You will be provided a 15 day
notice of any site investigation, and will have the opportuni to participate in all site investigations.
Date:
Telephone number:
Signature of appellant or agent.
For appeals on Initial Proffered Permits send this form to:
District Engineer, Wilmington Regulatory Division, Attn: Rachel Capito, 69 Darlington Avenue, Wilmington, North Carolina
28403
For Permit denials, Proffered Permits and Approved Jurisdictional Determinations send this form to:
Division Engineer, Commander, U.S. Army Engineer Division, South Atlantic, Attn: Mr. Phillip Shannin, Administrative
Appeal Officer, CESAD-PDO, 60 Forsyth Street, Room 10M15, Atlanta, Georgia 30303-8801
Phone: [phone]

PRELIMINARY JURISDICTIONAL DETERMINATION (PJD) FORM
BACKGROUND INFORMATION
A. REPORT COMPLETION DATE FOR PJD: 1/31/2020
B. NAME AND ADDRESS OF PERSON REQUESTING PJD: New Hanover County Airport Authority, Granseur
Dick, 1740 Airport Blvd, Wilmington, NC 28405
C. DISTRICT OFFICE, FILE NAME, AND NUMBER: Wilmington District, Circle K ILM Airport, SAW-2019-
01981
D. PROJECT LOCATION(S) AND BACKGROUND INFORMATION: Project area is located southeast of the
intersection of Airport Boulevard and N 23rd Street in Wilmington, New Hanover County, North Carolina.
(USE THE TABLE BELOW TO DOCUMENT MULTIPLE AQUATIC RESOURCES AND/OR
AQUATIC RESOURCES AT DIFFERENT SITES)
State: NC County: New Hanover City: Wilmington
Center coordinates of site (lat/long in degree decimal format): Latitude: 34.266784 Longitude:-77.916195
Universal Transverse Mercator:
Name of nearest waterbody: Smith Creek
E. REVIEW PERFORMED FOR SITE EVALUATION (CHECK ALL THAT APPLY):
❑ Office (Desk) Determination. Date:
® Field Determination. Date(s): 11/6/2019
TABLE OF AQUATIC RESOURCES INREVIEWAREA WHICH "MAY BE" SUBJECT TO REGULATORY
JURISDICTION.
Estimated amount of
Geographic authority to
Type of aquatic
latitude (decimal
Longitude (decimal
aquatic
aquatic resources in
(i.2.,
which the aquatic resource
Site Number
degrees}
degrees]
review area (acreage
wetland vs. non-
"may be" subject (i.e.,
and linear feet, if
wetland waters)
Section 404 or Section
applicable
10 4f}4
A
34.266927
-77.914764
150 linear feet
Non -wetland
Section 404
waters
B
34.265820
-77.915060,
94 linear feet
Non -wetland
Section 404
waters
C
34.265891
-77.917786
57 linear feet
Non -wetland
Section 404
waters
D
34.266361
-77.914830
0.07 acre
Wetland
Section 404
E
34.265821
-77.914965
0.05 acre
Wetland
Section 404
F
34.266060
-77.916802
0.04 acre
Wetland
Section 404
G
34.266520
-77.915190
0.07 acre
Wetland
Section 404
H
34.267425
-77.918440
0.02 acre
Wetland
Section 404

Estimated amount of
Type of aquatic
Geographic authority to
Latitude (decimal
Longitude (decimal
aquatic resources in
resources (Le.,
which the aquatic resource
Site Number
degrees)
degrees)
review area (acreage
Wand vs. non-
Wmay be" subject (i.e.,
and linear feet, if
wetland waters)
Section 404 or Secb,: ,n
applicable
10/404
1
34.267131
-77.918522
0.14 acre
Wetland
Section 404
J
34.266817
-77.918280
0.05 acre
Wetland
Section 404
K
34.266038
-77.917733
0.01 acre
Non -wetland
Section 404
waters
L
34.266178
-77.918108
0.04 acre
Non -wetland
Section 404
waters
1) The Corps of Engineers believes that there may be jurisdictional aquatic resources in the review
area, and the requester of this PJD is hereby advised of his or her option to request and obtain an
approved JD (AJD) for that review area based on an informed decision after having discussed the
various types of JDs and their characteristics and circumstances when they may be appropriate.
2) In any circumstance where a permit applicant obtains an individual permit, or a Nationwide General
Permit (NWP) or other general permit verification requiring "pre- construction notification" (PCN), or
requests verification for a non -reporting NWP or other general permit, and the permit applicant has
not requested an AJD for the activity, the permit applicant is hereby made aware that: (1) the permit
applicant has elected to seek a permit authorization based on a PJD, which does not make an official
determination of jurisdictional aquatic resources; (2) the applicant has the option to request an AJD
before accepting the terms and conditions of the permit authorization, and that basing a permit
authorization on an AJD could possibly result in less compensatory mitigation being required or
different special conditions; (3) the applicant has the right to request an individual permit rather than
accepting the terms and conditions of the NWP or other general permit authorization; (4) the applicant
can accept a permit authorization and thereby agree to comply with all the terms and conditions of that
permit, including whatever mitigation requirements the Corps has determined to be necessary, (5)
undertaking any activity in reliance upon the subject permit authorization without requesting an AJD
constitutes the applicant's acceptance of the use of the PJD; (6) accepting a permit authorization (e.g.,
signing a proffered individual permit) or undertaking any activity in reliance on any form of Corps
permit authorization based on a PJD constitutes agreement that all aquatic resources in the review area
affected in any way by that activity will be treated as jurisdictional, and waives any challenge to such
jurisdiction in any administrative or judicial compliance or enforcement action, or in any
administrative appeal or in any Federal court; and (7) whether the applicant elects to use either an AJD
or a PJD, the JD will be processed as soon as practicable. Further, an AJD, a proffered individual
permit (and all terms and conditions contained therein), or individual permit denial can be
administratively appealed pursuant to 33 C.F.R. Part 331. If, during an administrative appeal, it
becomes appropriate to make an official determination whether geographic jurisdiction exists over
aquatic resources in the review area, or to provide an official delineation of jurisdictional aquatic
resources in the review area, the Corps will provide an AJD to accomplish that result, as soon as is
practicable. This PJD finds that there "may be" waters of the U.S. and/or that there "may be"
navigable waters of the U.S. on the subject review area, and identifies all aquatic features in the
review area that could be affected by the proposed activity, based on the following information:

SUPPORTING DATA. Data reviewed for PJD (check all that apply)
Checked items should be included in subject file. Appropriately reference sources below where
indicated for all checked items:
Z Maps, plans, plots or plat submitted by or on behalf of the PJD requester:
® Data sheets prepared/submitted by or on behalf of the PJD requestor.
® Office concurs with data sheets/delineation report.
❑ Office does not concur with data sheets/delineation report. Rationale:
❑ Data sheets prepared by the Corps:
❑ Corps navigable waters' study:
® U.S. Geological Survey Hydrologic Atlas: 030300070808
❑ USGS NHD data.
® USGS 8 and 12 digit HUC maps.
® U.S. Geological Survey map(s). Cite scale & quad name: Wilmington
® Natural Resources Conservation Service Soil Survey. Citation: NRCS New Hanover County Soil Survey
® National wetlands inventory map(s). Cite name: USFWS NWI Manner
❑ State/local wetland inventory map(s):
❑ FEMA/FIRM maps:
❑ 100-year Floodplain Elevation is: (National Geodetic Vertical Datum of 1929)
® Photographs: ®Aerial (Name & Date): NC One Man Orthoima¢ery 2017
or ®Other (Name & Date): Landscape
❑ Previous determination(s). File no. and date of response letter:
❑ Other information (please specify):
IMPORTANT NOTE: The information recorded on this form has not necessarily been
verified by the Corps and should not be relied upon for later jurisdictional determinations.
CAPITO.RACHEL. DI91tallysl9nedb'
CAKIWACHELANN.1531276790
ANN.153627679,0 D3te'2020.013112:36:3S_0'W
Signature and date of Regulatory
staff member completing PJD
1 /31 /2020
Signature and date of person requesting PJD
(REQUIRED, unless obtaining the signature is
impracticable)1
1 Districts may establish timeframes for requester to return signed PJD forms. If the requester does not respond within the
established time frame, the district may presume concurrence and no additional follow up is necessary prior to finalizing an
action.

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North Carolina Secretary of State Search Results Page 1 of 1
Search ResuLts
4
Records Found: 1 Search Type: All Search Criteria: Circle K Stores,
Search Time: 8/27/2020 11:05 AM Search Again BV,_
Entity Name
Sos Id Date Formed
Circle K Stores Inc.
Prev Legal Name(s)
The Circle K Corporation
Circle K Convenience Stores, Inc.
0176043 110/25/1985
Status
i Current - Active O
Type
i
I
Business Corporation
https://www.sosnc.gov/online services/searchBusiness Registration_Results 8/27/2020

rf=
Mi- is. 61 ow
This instrument, a Deed of Release, made by the United States of A"Irtoa, Ing
by.,
and through Na Direetoe, Southow Region, of:the Federal Aviatloft Administration, .
Departsient of 'lticsnmporMien under and' pur4vant to, the powers and +6 horny cbatait�ed '
to the provisione of yablit Law all Slat . s Congreas,.(63 Stat' 700),.as amended, to the
County of New Hanover, a body Politio under the laws -of the state of North Carolina,
Witnesseth
� NI�REAg,
The United States of America acting by and.through the filar Assets Administrator and
the ceneral Services Administrator under and pursuant to the powers and authority
contained in the provisions of the Surplus Property Act of 19", as mended, and
applicable rules, regulations and orders, did by Instruments of Transfer dated
December 8, 1947, May 7, 1948'and September to, 1961, realise, release and forever
quitclaim to the County of New Hanover, North Carolina, a body politic under the `
lava of the State of North Carolina, its successor$ and assigns, sll rights, title
f
and interest of the United States of America in and to certain property know as
gluethenthal Field, also known as New Nanovar County Airport, subject to certain terse,
conditions, reservations, and restrictions and,
i
WIMRFAS,
The County of New Hanover has requested the United States of America to release the
hereinafter described property from all terms, conditions, reservations, and
restrictions of said Instruments of Transfer and,
MIERUSS
:he Directors, Southern Region of the Federal Aviation
g 1Wmitaistration has dots, nod
�! that the release of the property hereinafter described will not prevent a
� P cconplishi»g
i the purpose for which the property was made subject to the terms, conditions, reset-
; vations, or restrictions, and to necessary to protect or ad
vasiee the Interests of
t°
tee United States in civil aviation._
NOW THER270R6
S:
Por and in consideration of the above -expressed recitals and of the benefite to
r
accrue to the United States and to civil aviation, the U%nited States of America,
upon inclusion by the County of New Hanover in the Instruments of Transfer eomraying
Ititle to the hereinafter described real property of provisions as followet
(1) lhat the County of New Hanover reserve unto itself its successors and
aseians for the g144 and 'OT :.:z .,..a. •.. ... .

tof4x . Soo
property hereinafter deeortbod• together with the right to aausa 1q said ;.
airspace such ii6i5e as wY be laberent in the operetica of 4ivil.,,and ailitary
airerift, natr lsnowa or hereafter used, for navigat oa of .or flight ip the !�
said airspace, and for usa of sold..&";apacd for lauding t&i !'
• ng•�off frow ; 4
or operating non the a" Hanovett County Airport,
(2) That the County of N6V Nanover reserves for itaeif its ouocessors.&A assigns I
for the use and banefit of the Department of Defense the right to operate an
New Hanover County Airport any electromagnetici radiating device without i•
restriction.
i
(3) That the craotes expressly agrees for itself, its successors and assigns
to restrict the height of structures, objects of natural growth and other
obstructions on the hereinafter described real property to a height of not
more than 160 feet above.sea level, I
(4) That the Grantee expressly agrees for itself, its successors and assigns to
prevent any use of the hereinafter described real property which would inter-• i
fere with landing or taking off of civil at military aircraft at tha New
Hanover Airport, including electronic interference and !
• control Of ei@CtrO.
magnetic spectrum radiation that might inhibit airport operations, or other. 1#
visa constitute an airport hazard, i
hereby releases the said real property from the term, conditions, reservations and 1!
restrictions as contained is the abova-mentioaod lastruments of Transfer from the '
i
United States of America to the County of New Hanover dated December S. 1947= pay 7, t
194E and September 18, 1961, which real property is described as _ollav-at'
All of that certain tract or parcel of land lying and being in the Cava gear
Township. New Hanover County North Carolina and being a part of Raw Hanover
County Airport:
BEGINNING at a concrete monument, a common corner of New Hanover County f
Airport and Electric Bottling
Company, said Bomsnent being North 79 degrees
I;
38 minutes East along a common line of the above owners 1000.0 feet from on
old concrete monument, mother common corner of said owners, said old
I
monument,being North 33 degrees 19 minutes East along another easmoa line
of said owners 687.36 feet from another old- concrete mongu nt, a cosmos
corner of said owners, this old ==mosmt being 6outh 39 degrees 30 minutes
- i

. • boot PACE $76
3 H.
i Bast rloag anothes ceiiaoli line Of said owners 592.02 feet from 40 old t
°0l t0 isoauaisnt is t6to Esate" "via of the A.C.16R.R, right -of -nay . k
(130:0 fast +fide still boirig the Kit ington and Veldon Braach) fuanirig
thence from said Eegigagag point North 3 degrees ainutes.Bdst along i
commoh line of said owners 208.71 faces ehenee ltoreh.79 degrees 37-3/4
minutes best 97.28 feet to a concrete Moewaeat,in the western line of
State Road No. 1311 (60-foot r
ight-of-vay)= thence South 2 degrees 8% minutes
Rest along said line of said Road 210.0 feet to a concrete monument; thence
South 80 degrees 53 minutes Nest 101.18 feet to the point. of Beginning, the
sane containing 0."S acres ad being a portion of the Now Nanorer County
k
Airport tract. t
By its acceptance of this Deed of Release the County of Nov Naaover covenants and
'• agrees for itself, its successors and assigns, to comply with and observe all of
the conditions and limitations hereof, Alch aaa exprassYy 1im;fed to the above•
described real property.
IN WITMIS
SE , TBB WXTBD STATES OF ICA has caused this Instrument to
be executed .. of We--r,UA day of .
� 19 �.
UNIT® STATES OF AMBRICA
The Administrator of the Federal Aviation Administration
SEAL
ector, Southern egion
Federal Aviation Administration
Department of Transportation

* • AT ' IlNlfi . 87, .
$SAT$ OF GEORGIA) 7
COUNTY OF FULTON)
op this ,day 'of �9 before ma,
y a Notatry Public iq and ttlr tla County of
V
State of peesonaily appeared
kntown to :ate to ba the Director. Southmcn Region, ;
Federal Aviation Administration, and knesn to me to be the person whose Asps is }
subscribed to the within Inetr Unt and acknowledged that he executed the-saee on
behalf of the Administrator of the Federal Aviation Administration and the United j
States of America.
WITNESS spy hand and official seal.
M' ' ix 1
New Hanover County, north Carolina SEAL)
By a/
Titl t.Jw,e trn.� ws YI1s 19..��r My Commission Binpirnt
WAYS UP NORTH CAROLINA
New IleeoitF ewunty
The Fonegoint QriitleW � •;
Notarjr'A�i�ltcof New�l�r Caaeb.
is adiedked to be eonvel. Iwt the inure-
Mont with IM Qeell&do be Ift"dI&
. Drews bs
to

Application Completeness Review Checklist {Non -Transfers} - Short Version
N
Project Nar*le: i M [ 4C,76� (L WL - A r,_4 r 5
_ Date Delivered to W I R0 %f] p
Project County/Location: Location: i`'��)' n y
J tl'ir 71 + H o d RIMS Received/Accented Date: 1 o
Rule(s): F-120 L7 Coastal F-12008 Coastal P1995 Coastal SIMS Acknowledged Date':
Phase 11 ❑Universal M1988 Coastal
Permit Action: New New Permit #z:
Minor Mod / Renewal Existing Permit #: _5;.3�j D •I
Permit Type: �D LD 0,eraii / HD &i_D Combo r-xpriatlon Date3.
Genera Perin! i OffsrtE / Exempt / Rescission �[fsiteto SW>3:
DLot is in Master Perrnit'
FiPE Cert on File?
Development Type:
Commercial / Residential / Othe° 406
Subdivided?: Subdivision or Single Lot
Permittee Type & Documents Needed:
E]PropeM, Owner(s)
Purchaser
Di_essee
_]Viabie?
�Viaaie?
�1'iable?
Deed
EPur&iase Agmt
Lease
MNot Subdividad:
Deed
Subdivision: Common Area Deed
0 11 0A ❑Developer
FiViable' OViabie?
Election Minutes
®$505 (within 6mo) Check#(s): f3lf513
(T new form or for older forms. 1 orpnol per SCM)
El Soils Report (lnfil or PP)
®Calculations (signed/sealed)
Deed Restrictions, if subdivided
lProject Narrative
jj'�gUSGS Map (or on file?) Subject to SA?: Y / N
Plans (2 Sets)
PE Certification
Electronic Copies
Easements, Recorded (2017 Rules)
Subject to ORW_�•
'Enter B1MS Acknowledged Date on this Sheet
2For New Projects -Enter New Permit # on Suppiements & Deed Restiction Templates.
=i w; irl f months and thev are requesting a mod: STOP Needs a renewal first_
EMAILED ENGINEER DATE:
REVIEWER NAME:
Comments:
3 :wUIV,Reference Lioran..FrocedureslC°.ecFc!isrs'.Comp-e.eness Review Checkl ist_2020 0131
[--]No Fee
Y / N