SW8060530_HISTORICAL FILE_20180223

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
2.d18 0223
YYYYMMDD

ROY COOPER
Governor
t
MICHAEL S. REGAN
Secretary
Energy, Mineral& WILLIAM E. (TOBY) VINSON, JR.
D
Land Resources
ENVIRONMENTAL OUALITY
February 23, 2018
UNC Wilmington
Attn: Vice Chancellor for Business Affairs
C/o Mark Morgan, Associate Vice Chancellor for Business Affairs -Facilities
601 S. College Rd.
Wilmington, NC 28403
Subject: Stale Slormwater Management Permit No. SW8 060530
Hurst Hamilton Parking Lots
Project with Areas of both High Density and Low Density
New Hanover County
Dear Mi. Morgan
The Wilmington Regional Office received a complete, modified State Stonnwater Management Permit
Application for the subject project on February 22, 2018, Staff review of the plans and specifications has
determined that the project, as proposed, will comply with the Stormwater Regulations set forl'h in Title
15A NCAC 2H.1000 effective January 1, 2017. We are forwarding modified Permit No. SW8 060530
dated February 23, 2018, for the construction, operation and maintenance of the stormwater control
measures (SCMs), built -upon areas, as well as the stormwater collection system and/or vegetated
conveyance system associated with the subject project. Please add the atioched plans to the previously
approved plan set. Please replace the previous application (SWU-101), supplement, and operation and
maintenance agreement with the attached modified versions.
On August 5, 2009, the Governor signed Session Law 2009-406. This law impacted any development
approval issued by the former Division of Water Quality under Article 21 of Chapter 143 of the General
Statutes, which was current and valid at any point between January 1, 2008, and December 31, 2010. The
law extended the effective period of any stormwater pennit that was set to expire during this time frame
to three (3) years from its current expiration date. On August 2, 2010, the Governor signed Session Law
2010-177, which granted an extra year for a total of four (4) years extension. Accordingly, this permit
shall now be effective from the date of issuance until dune 16, 2020, which includes all available
extensions. The pernultee andlorproiect remain subject to the conditions and limitations asspecified
therein and does not supersede any other agency permit that may be required.
Please pay special attention to the permit conditions regarding the operation and maintenance of the
SCMs, stormwater collection system, and/or vegetated conveyances; the limitation of built -upon area;
modification of the project; the procedures for changing ownership of and/or transferring the permit; and
the need to renew the permit. Please also pay attention to the permit conditions that requires the
recordation of deed restrictions and protective covenants, casements, and the maintenance agreement,
which must all be provided along with certification upon completion of the project. Failure to comply
with these requirements will result in future compliance problems.
Please refer to Attachment 1 for a detailed description of the current proposed major modification and a
list of all the past modifications approved during the effective period of the permit.
If any parts, requirements, or limitations contained in 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 OAl-1 within thirty (30) days of receipt of this permit. You should contact the OAH
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.
Statc of Nonh Carolina I Cnvironmental Quality I Encrgy. Mineral and Land Resources
Wilmington Regional Office 1127 Cardinal Drive Extension I Wilmington. NC 29405
910 796 7215

State Stormwater Permit No. SW8 060530
Page 2 of 9
If you have any questions, or need additional information concerning this matter, please contact Christine
Hall in the Wilmington Regional Office, at [phone]. `
Sincerely,
William E. (Toby) Vinson, Jr.. PE. CPESC, CPM, Interim Director
Division of Energy, Mineral and Land Resources
Enclosures: Attachment A — Certification Forms
Attachment I — Permitting History
GDS/canh: AV\Stormwater\Permits & 1'rojects\2000V060530 HDA2075 02 permit 060530
cc : Calen Jamison, PE, Project Manager; UNCW
Daryl Riggings, PE; McAdams
Wilmington Regional Office Stormwater File
State of Norl h CaaroGna I Ilmlronnwwa1Quallty I Envrgy.Mlncraland Land Resources
Wilmingtun Regional04fice 1127Caidlnal Ddvc Extension I Wilminglun.NC 25405
410 796 7215

State Stormwater Management
Permit No. SW8 060530
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF ENERGY, MINERAL AND LAND RESOURCES
STATE STORMWATER MANAGEMENT PERMIT
DEVELOPMENT WITH AREAS OF BOTH HIGH DENSITY AND LOW DENSITY
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
UNC Wilmington
Hurst Hamilton Parking Lots
Hurst Drive and Wagoner Drive, Wilmington, New Hanover County
Ko tal
construction; operation and maintenance of one (1) wet pond ("stormwater control measures" or
"SCMs") as well as one (1) area of 24% low density and one (1) area of redevelopment in compliance
with the provisions of Title 15A NCAC 2H .1000 effective January 1, 2017 (the "stormwater rules") and
the approved stormwater management plans, application, supplement(s), specifications, and other
supporting data (the "approved plans and specifications") as attached and/or 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 16, 2020 and shall be subject to the
following specified conditions and limitations:
I. DESIGN STANDARDS
1. This permit is effective only with respect to the management and volume of stormwater
described in the approved plans and specifications. The maximum amount of built -upon area
(BUA) allowed for the entire project is 647,989 square feet.
2. The redevelopment portion of this project is exempt from State Stormwater permitting
requirements under the following conditions: 1) The project must be constructed as shown on
the plans submitted to this Office; 2) the proposed redeveloped BUA of 14,555 square feet does
not exceed the existing BUA of 14,760 square feet, and 3) The proposed stormwater control
(vegetated sheet flow and a vegetated channel) provides equal protection of surface waters as
the existing stormwater control (vegetated sheet flow and a vegetated channel).
3. The low density area must not exceed 24% per the requirements of the stormwater rules. Within
this low density area, this permit covers the construction of a total of 25,145 square feet of BUA;
which includes 18,253 square feet of proposed BUA and 6,892 square feet of previously
permitted BUA. This low density area excludes 22,215 square feet of existing built -upon area in
accordance with 15A NCAC 02H.1003(1)(b).
4. The low density area, Drainage Area 2, has maximized dispersed flow of stormwater runoff
through vegetated areas and minimized the channelization of flow. Stormwater runoff that could
not be released as dispersed flow may be transported by vegetated conveyances with minimum
side slopes of 3:1 (H:V) designed to not erode during the peak flow from the 10-year storm event
as defined in the stormwater rules and approved by the Division.
Page 1 of 5

State Stormwater Management
Permit No. SW8 060530
5. Within the low density area, Drainage Area 2, no piping shall be allowed except those minimum
amounts necessary to direct stormwater runoff beneath a BUA such as a road or driveway when
it cannot be avoided.
6. The drainage area for the on -site stormwater system will be limited to the amount 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 area of this project must be directed into the permitted
stormwater control measure. The stormwater control measure has been designed using the
runoff treatment method to handle the runoff from 608,289 square feet of impervious area. This
permit does not provide any allocation of built -upon area for future development.
7. A 50-foot wide vegetative setback must be provided and maintained adjacent to all surface
waters, 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 in accordance with the stormwater rules and the approved plans
and specifications. Within the low density area all stormwater runoff, including roof drains, shall
be released as dispersed flow no closer than at the edge of the vegetated setback and at no
time shall stormwater runoff be piped into or through the setback.
8. The stormwater control measure is permitted based on the design criteria presented in the
sealed, signed and dated supplement and as shown in the approved plans and specifications.
These stormwater control measure must be provided and maintained at the design condition.
The approved supplement is incorporated by reference into this permit.
9. The peak flow from the 10-year storm event shall not cause erosion downslope of the
stormwater outlet discharge point.
10. Decorative spray fountains will be allowed in the stormwater treatment system if documentation
is provided demonstrating that the proposed fountain will not cause resuspension of sediment
within the pond or cause erosion of the pond side slopes.
11. When using a wet pond for irrigation, it is recommended that some water be maintained in the
permanent pool, the vegetated shelf is planted with appropriate species that can handle
fluctuating conditions, and human health issues are addressed.
12. The SCM landscape planting plan shown in the approved plans shall be followed in its entirety
during construction. After the plants are established, the operation and maintenance agreement
must be followed.
13. The stormwater system is permitted as a variation to the requirements under Title 15A NCAC
20H.1003(6) as the forebays (existing and proposed) exceed the 15-20% minimum design
criteria. The proposed system provides equal or better stormwater control and equal or better
protection of surface waters. If the proposed system is found to not meet the intent of the
stormwater rules, the stormwater control measure will have to meet the requirements of the
stormwater rule or another alternative must be proposed and a permit modification will be
required.
II. SCHEDULE OF COMPLIANCE
1. The project and SCM shall be constructed, operated and maintained in accordance with the
conditions of this permit and the approved plans and specifications.
2. The on -site stormwater system shall be entirely constructed, vegetated, and operational prior to
the construction of any development within the drainage area, per the approved plans and
specifications.
3. During construction, erosion shall be kept to a minimum and any eroded areas of the on -site
stormwater system will be repaired immediately. If the stormwater system is 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.
Page 2 of 5

I
State Stormwater Management
Permit No. SW8 060530
4. All stormwater control measures, stormwater collection systems vegetated conveyance systems,
and/or maintenance accesses must be located in public rights -of -way, dedicated common areas
that extend to the nearest public right-of-way, and/or permanent recorded easements that
extend to the nearest public right-of-way for the purpose of inspection, operation, maintenance;
and repair.
5. The permittee shall provide and perform the operation and maintenance necessary, as listed in
the signed Operation and Maintenance Agreement, to assure that all components of the
permitted on -site stormwater system functions at the approved design condition. The approved
Operation and Maintenance Agreement is incorporated by reference into this permit and must
be followed in its entirety and maintenance must occur at the scheduled intervals.
6. The operation and maintenance agreement must be recorded with the Office of the Register of
Deeds.
7. Records of maintenance activities must be kept and made available upon request to authorized
personnel of the Division. The records will indicate the date, activity; name of person performing
the work and what actions were taken.
8. 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.
9. 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.
10. Upon completion of the project, the permittee shall determine whether or not the project is in
compliance with the permitted plans and take the necessary following actions:
a. If the permittee determines that the project is in compliance with the permitted 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 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 permitted 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.
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:
a. Any modification to the approved plans and specifications, regardless of size including the
stormwater control measures, built -upon area: details, etc.
b. Redesign or addition to the approved amount of built -upon area or to the drainage area.
c. Further development, subdivision, acquisition, lease or sale of any, all or part of the project
area as reported in the approved plans and specifications.
d. Altering, modifying, removing, relocating, redirecting, regrading or resizing of any
component of the approved stormwater control measure, stormwater collection system
and/or vegetative conveyance system shown on the approved plan.
e. The construction of any allocated future BUA.
f. The construction of any permeable pavement for BUA credit that was not included in the
approved plans and specifications.
g. The construction of any #57 stone area, public trails, or landscaping material to be
considered a permeable surface that were not included in the approved plans and
specifications.
In. Other modifications as determined by the Director.
Page 3 of 5

State Stormwater Management
Permit No. SW8 060530
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 modified 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. Any individual or entity found to be in noncompliance with the provisions of a stormwater
management permit or the requirements of the stormwater rules is subject to enforcement
procedures as set forth in NCGS 143 Article 21.
2. The issuance of this permit does not preclude the permittee from complying with and obtaining
any other permits or approvals that are required for this development to take place, as required
by any statutes; rules, regulations, or ordinances, which may be imposed by any other Local,
State or Federal government agency having jurisdiction. Any activities undertaken at this site
that cause a water quality violation or undertaken prior to receipt of the necessary permits or
approvals to do so are considered violations of NCGS 143-215.1, and subject to enforcement
procedures pursuant to NCGS 143-215.6.
3. If the facilities fail to perform satisfactorily or fail to meet the requirements of a low density area,
the permittee shall take immediate corrective actions. This includes actions required by this
Division and the stormwater rules such as the construction of additional or replacement on -site
stormwater systems. These additional or replacement measures shall receive a permit from the
Division prior to construction.
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 State Stormwater Request Form
for Permit Transfer or Permit Information Update; accompanied by the 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. Any ownership change including:
i. The sale or conveyance of the project area in whole or in part, except in the case of
an individual lot sale that is made subject to the recorded deed restrictions and
protective covenants;
ii. Dissolution of the partnership or corporate entity, subject to NCGS 57D-2-01(e) and
NCGS 57D-6-07;
b. Bankruptcy;
c. Foreclosure, subject to the requirements of Session Law 2013-121;
d. A name change of the current permittee;
e. A name change of the project;
f. A mailing address change of the permittee;
5. The permittee is responsible for compliance with all terms and conditions of this permit until 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 permit.
6. The permittee grants Division Staff permission to enter the property during normal business
hours to inspect all components of the permitted project.
7. 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.
8. Approved plans, application documents, supplements, calculations, operation and maintenance
agreement, and specifications for this project are incorporated by reference and are enforceable
parts of the permit. A copy of this permit, application, supplements, operation and maintenance
agreement, and approved plans and specifications shall be maintained on file by the permittee.
Page 4 of 5

State Stormwater Management
Permit No. SW8 060530
9. Unless specified elsewhere; permanent seeding requirements for the on -site stormwater system
must follow the guidelines established in the North Carolina Erosion and Sediment Control
Planning and Design Manual.
10. 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.
11. 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. 1 045(3).
Permit modified and reissued this the 2311 day of February 2018.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
j7;,William Ed(Toby) Vinson, Jr., PE. CPESC, CPM, Interim Director
Division of Energy; Mineral and Land Resources
By Authority of the Environmental Management Commission
Permit Number SW8 060530
Page 5 of 5

State Stormwater Management
Permit No. SW8 060530
Attachment A
Certification Forms
The following blank Designer Certification forms are included and specific for this project:
• As -Built Permittee Certification
• As -Built Designer's Certification General MDC
• As -Built Designer's Certification for Wet Detention Pond Project
• As -Built Designer's Certification for Low Density Projects
A separate certification is required for each SCM. These blank certification forms may be copied and
used, as needed, for each SCM and/or as a partial certification to address a section or phase of the
project.
Page 1 of 1

State Stormwater Management
Permit No. SW8 060530
AS-13UI1,1' I'I:RNII7"I'I;I: CERTIFICATION
I hereby state that I am the current permittee for the project named above, and I certify by my signature below,
that the project meets the below listed Final Submittal Requirements found in NCAC 021-1.1042(4) and the
terns, conditions and provisions listed in the permit documents, plans and specifications on file with or provided
to the Division.
Check here ifthis is a partial certification. Sect ion/phase/SCN9 V
Check here ifthis is par ofa Fast Track As -built Package Submittal.
Printed
County of
a Notary Public in the State of
do hereby certify that
personally appeared before me this day of 120
and acknowledge the due execution of this as -built certification. (S1,A1.,)
Witness my hand and official seal
My commission expires
Permittee's Certification NCAC .1042(4)
Completed i
Provided
N/A
A. DEED RESTRICTIONS / BUA RECORDS
1. The deed restrictions and protective covenants have been recorded and
Y or N
contain the necessary language to ensure that the project is maintained
consistent with the stormwatcr regulations and with the permit conditions.
2. A copy of the recorded deed restrictions and protective covenants has been
Y or N
provided to the Division.
3. Records which track the 13UA on each lot are being kept. (SceNotc 1)
Y or N
13. MAINTENANCE, ACCESS
1. The SCMs are accessible for inspection, maintenance and repair.
Y or N
2. The access is a minimum of 10 feet wide.
Y or N
3. The access extends to the nearest public right-of-way.
Y or N
C. EASEMENTS
1. The SCN9s and the components of the runoff collection / conveyance system
Y or N
are located in recorded drainage casements.
2. A copy of the recorded plat(s) is provided.
Y or N
D. SINGLE FAMILY RESIDENTIAL LOTS - Plats for residential lots that
Y or N
have an SCM include the following:
I. The specific location of the SCM on the lot.
Y or N
2. A typical detail for the SCM.
Y or N
3. A note that the SCN9 is required to meet stormwatcr regulations and that the
lot owner is subject to enforcement action as set forth in NCGS 143 Article
Y or N
21 if the SCM is removed. relocated or altered without prior approval.
E. OPERATION AND MAINTENANCE AGREEMENT
Y or N
1. The O&M Agreement is referenced on the final recorded plat.
Y or N
2. The O&M Agreement is recorded with the Register of Dceds and appears in
Y or N
the chain oftitle.
F. OPERATION AND MAINTENANCE PLAN — maintenance records are
y N
beingkept in a known set location for each SCM and are available for review.
or
G. DESIGNER'S CERTIFICATION FORM — has been provided to the
Y or N
Division.
Notel- Acceptable records include ARC approvals, as -built surveys, and county tax records.
Page 1 of 8

State Stormwater Management
Permit No. SW8 060530
Provide an explanation for every requirement that was not met, and for every ''N/A" below. Attach
additional sheets as needed.
Page 2 of 8

State Stormwater Management
Permit No. SW8 060530
AS-IIIiILT llI;SIGNI?R'S CEIYI'IPICA'1'1(lN GI?NERAL MDC
1 hereby state that I am a licensed professional and I certify by my signature and seal below, that I have observed
the construction of the project named above to the best of my abilities with all due care and diligence, and that
the project meets the below listed General NIDC found in NCAC 021-1.1050 in accordance with the permit
documents, plans and specifications on file with or provided to the Division, except as noted on the "AS -
BUILT" drawings, such that the intent of the stormwater rules and statutes has been preserved.
Check here if this is a partial certification. Sect ion/phase/SCNf ii?
Check here if this is a part of a Fast -Track As -Built Package Submittal per .1044(3).
Check here if the designer did not observe the construction, but is cenifying the project.
Check here if pictures of the SCM are provided.
Printed
NC Registration Number Date
SPAL:
Consultant's Mailing Address:
City/State/ZIP
Phone Number
Consultant's Email address:
1) Circle N if the as -built value differs from the flan. If N is circled, provide an explanation on Page 2.
ON/B = not evaluated (provide explanation on page 2) 3N/A = not applicable to this SCNI or project.
Consultant's Certification NCAC .1003((3) & General MDC .1050
OAs-built
ON/E
OO N/A
A. TREATMENT REQUIREMENTS
1. The SCM achieves runoff treatment.
Y or N
2. The SCN-I achieves runoff volume match.
Y or N
3. Runoff from offsite areas and/or existing 13UA is bypassed.
Y or N
4. Runoff from offsite areas and/or existing BUA is directed into
Y or N
the permitted SCM and is accounted for at the full build -out
potential.
5. The project controls runoff through an offsitc permitted SCNf
Y or N
that meets the requirements of the MDC.
6. The net area of new BUA increase for an existing project has
Y or N
been accounted for at the appropriate design storm level.
7. The SCM(s) meets all the specific minimum design criteria.
Y or N
B. VEGETATED SETBACKS / BUA
I . The width of the vegetated setback has been measured from
Y or N
the normal pool of impounded waters, the N-lI IW line of tidal
waters or the top of bank of each side of rivers or strunns.
2. The vegetated setback is maintained in grass or other
Y or N
vegetation.
3. 131JA that meets the requirements ofNCGS 143-214.7 (b2)(2)
Y or N
is located in the setback.
4. 13UA that does not meet the requirements of NCGS 143-214.7
Y or N
(b2)(2) is located within the setback and is limited to:
a. publicly funded linear prgjects (road, greenway sidewalk)
b. Water -dependent structures
c. Minimal footprint uses (utility poles, signs, security
lighting and appurtenances
5. Stormwater that is not treated in an SCM is released at the
Y or N
edge of the setback and allowed to flow through the setback as
dispersed flow.
Page 3 of 8

State Stormwater Management
Permit No. SW8 060530
OAs-built
ON/E
OO N/A
C.
STORM WATER OUTLETS — the outlet handles the peak flow
y
N
from the 10 ear storm with no downslope erosion.
or
D.
VARIATIONS
1. eA variation (alternative) from the stormwater rule provisions
has been implemented.
or
2. "I'hc variation provides equal or better stonnwatcr control and
Y
N
cc ual or better protection of surface waters.
or
E.
COMPLIANCE WITH OTHER REGULATORY
Y
N
PROGRAMS has been met.
or
F.
SIZING -the volume of the SCM takes the runoff from all
surfaces into account and is sufficient to handle the required storm
Y
or
N
depth.
G.
CONTAMINATED SOILS — infiltrating SCM's are not located
Y
or
N
in or on areas with contaminated soils.
H.
SIDE SLOPES
1. Vegetated side slopes are no steeper than 311:1 V.
Y
or
N
2. Side slopes include retaining walls; gabion walls; or other
y
or
N
surfaces that are steeper than 3H:1 V.
3. Vegetated side slopes are steeper than 311:1 V (provide
Y
or
N
Supporting documents for soils and vegetation).
1.
-EROSION PROTECTION
1. The inlets do not cause erosion in the SCM.
Y
or
N
2. The outlet does not cause erosion downslope of the discharge
Y
or
N
point during the peak flow from the 10 year storm.
J.
EXCESS FLOWS — An overflow / bypass has been provided.
Y
or
N
K.
DEWATERING —A method to drawdown standing water has
Y
or
N
been provided to facilitate maintenance and inspection.
L.
CLEAN OUT AFTER CONSTRUCTION —the SCM has been
Y
or
N
cleaned out and converted to its approved design state.
M.
MAINTENANCE ACCESS
1. The SCM is accessible for maintenance and repair.
Y
or
N
2. The access does not include lateral or incline slopes >3:1.
Y
or
N
N.
DFSIGNF,R QUALIFICATIONS (FAST -TRACK PERMIT) —
The designer is licensed under Chapters 89A, 89C, 89E, or 89F of
Y
or
N
the General Statutes.
Provide an explanation for every MDC that was not met, and for every item marked "N/A" or "N/E",
below. Attach additional pages as needed:
Page 4 of 8

State Stormwater Management
Permit No. SW8 060530
AS-BGII� 1' DESIGNEWS CERTIFICATION FOR WET DF; fE HON POND PROJ1CT
1 hereby state that I am a licensed professional and I certify by my signature and seal below, that I have observed
the construction of the project named above to the best of my abilities with all due care and diligence, and that
the project meets all of the NIDC found in NCAC 0211.1053, in accordance with the permit documents, plans
and specifications on file with or provided to the Division_ except as noted on the "AS -BUILT' drawings, such
that the intent of the stormwater rules and the general statutes has been preserved.
Check here if this is a partial certification. Sect ion/phase/SCNI .'.'?
Check here if this is part of a Fast -Track As -Built Package Submittal per. 1044(3).
Check here if the Designer did not observe the construction, but is certifying the project.
Check here if pictures ofthe SCAM are provided.
Printed Name
NC Registration Number
SEAL:
Signature_
Date
Consultant's Mailing Address:
City/State/%IP
Phone Number
Consultant's Email address:
T Circle N if the as -built value differs from the Plan/permit. If N is circled, provide an explanation on page 2
OO N/E = not evaluated (provide explanation on page 2) ON/A = not applicable to this project or SCAM.
This Certification must be completed in conjunction with the General NIDC certification underNCAC 021-1.1050
Consultant's Certification (.VIDC .1053)
Or As -built
OO N/E
OO N/A
A. Foreba / Depths / Fountain
1.
The available Sediment storage is consistent with the approved
Y
N
plan and is a minimum of 6 in.
or
2.
Water [low over the forebay bean into the main pond occurs at a
Y
N
non -erosive velocity.
or
3.
The provided Eorebay Volume is 15%-20% of the main pool
Y
N
volume.
or
4.
The Forebav entrance elevation is deeper than the exit elevation
Y
N
into the pond.
or
5.
The Average Design Depth of the main pond below the
y
N
permanent pool elevation is consistent with the permitted value?
or
6.
Fountain documentation is provided.
Y
or
N
B. Side slopes / Banks / Ve 'etated Shelf
I.
The width of the Vegetated Shelf is consistent with the approved
Y
N
plans and is a minimum of 6 feet.
or
2.
The slope of the Vegetated Shelf is consistent with the approved
Y
N
Mans and is no steeper than 6:1.
or
C. As -built Main Pool / Areas / Volumes / Elevations
I .
']'he permanent pool surface area provided is consistent with the
I Y
N
permitted value.
or
2.
"The Temporary Pool Volume provided is consistent with the
Y
N
permitted value.
or
3.
The permanent pool elevation is consistent with the permitted
Y
N
value.
or
4.
The temporary pool elevation is consistent with the permitted
Y
N
value.
or
Page 5 of 8

State Stormwater Management
Permit No. SW8 060530
tOAs-built
ON/E
OO N/A
D. Inlets / Outlet / Drawdown
l .
The design volume draws down in 2-5 days.
Y
or
N
2.
The sire of the Orifice is consistent with the permitted value.
Y
or
N
3.
A trash rack is provided on the outlet structure.
Y
or
N
4.
Hydrologic impacts to the receiving channel are minimized from
Y
N
the I yr 24 hr stortn discharge?
or
5.
The inlets and the outlet location are situated per the approved
Y
N'
Ian and avoid short-circuiting.
or
F. Ve
etation
I.
The vegetated shelf has been planted with a minimum of')
Y
N
diverse species.
or
2.
The vegetated shelf plant density is consistent with the approved
plans and is no Tess than 50 plants per 200 sf or no Iess than 24
Y
or
N
inches on center.
Provide an explanation for every MDC that was not met; and for every item marked 'N/A" or "N/F
below. Attach additional pages as needed:
Page 6 of 8

State Stormwater Management
Permit No. SW8 060530
AS -BUILT DESIGNER'S CERTIFICATION FOR LO)V D1:NSITY PROJECTS
I hereby state that I am a licensed professional and I certify by my signature and seal below that I have observed
the construction of the low density project named above to the best of my abilities with all due care and
diligence, and that the project meets all of the MDC found in NCAC 021-1.1003 and is consistent with the permit
documents; plans and specifications on file with or provided to the Division, except as noted on the "AS -
BUILT" drawings, such that the intent of the stormwater rules and the general statutes has been preserved.
Check here if this is a partial certification. Section or phase?
Check here ifthis.is part of a Past -Track As -Built Package Submittal per .1044(3).
Check here if the Designer did not observe the construction but is certifying the project.
Check here if pictures of the project are provided.
Printed Name
NC Registration Number
SEAL:
Signature
Consultant's Mailing Address:
City/State/ZIP
Phone Number
Consultant's Email Address:
OO Circle N if the as -built value differs from the Plan/Permit. If N is circled, provide an explanation on page 2.
OO N/E = not evaluated (provide explanation on page 2) OO N/A = not annlicable to this protect / plan.
Consultant's Certification (MDC .1003)
tOAs-built
Oz N/E
Oa N/A
A. Project Density and Built -Upon Area
1. The project has areas of high density based on natural drainage
Y N
--r-
area boundaries, variations in land use or construction phasin .
or
2. The project's built -upon area does not exceed the maximum limit
Y N
specified in the permit.
or
B. Dispersed Flow —the project maximizes dispersed flow through
Y N
vegetated areas and minimizes channelized flow.
or
C. Vegetated Conveyances
1. Stormwater that is not released as dispersed flow is transported
Y N
by vegetated conveyances.
or
l
2. The project has a minimal amount of non -vegetated conveyances
y N
to reduce erosion.
or
3. Other than minimal piping under driveways and roads, no piping
Y N
has been added beyond what is shown on the approved plans.
or
4. Side slopes are no steeper than 3H:1 V.
Y or N
5. The conveyance does not erode in response to the peak flow from
Y N
the 10 year storm.
or
D. Curb outlet systems - the project uses curb & gutter with outlets to
Y N
grassed swales or vegetated areas that meet the following criteria:
or
1. The swalc or vegetated area can carry the peak flow from the 10
Y N
storm at a non -erosive velocity.
or
2. The longitudinal slope of the Swale or vegetated areas does not
Y N
exceed 5%.
or
3. The swale has a trapezoidal cross-section and a minimum bottom
Y N
width of two feet.
or
4. The minimum length of the swale or vegetated area is 100 feet.
Y or N
5. Side slopes are no steeper than 31-I:1 V.
Y or N
6. The project utilizes treatment swales designed per Section .1061
Y N
in lieu of the curb outlet system requirements.
or
Page 7 of 8

State Stormwater Management
Permit No. SW8 060530
CAs-built
©N/E
OO N/A
E. Vegetated Setbacks
I . The width of the vegetated setback is
1' or N
2. The width of the vegetated setback hass be been measured from the
normal pool of impounded waters, the NIHW line of tidal waters,
Y or N
or the top of bank of each side of rivers or streams.
3. The vegetated setback is maintained in grass or other vegetation.
Y or N
4. BUA that meets the requirements of NCGS 143-214.7(b2)(2) is
N
located in the setback.
or
5. 131JA that does NOT meet the requirements of NCGS 143-
214.7(b2)(2) is located within the setback and is limited to:
a. Publicly funded linear projects (road, greemvay, or sidewalk)
Y N
b. Water dependent structures
or
c. Minimal footprint uses such as poles, signs, utility
appurtenances, and security lights.
6. The amount of 13liA within the setback is minimized and
channeling of the runoff from the 13UA has been avoided.
Y or N
7. Stonnwatcr is not discharged (via swalc or pipe) through a
vegetated setback. Stonnwater is released at the edge of the
y N
setback and allowed to flow through the setback as dispersed
{]OW.
or
F. Outlets — stormwater outlets do not cause erosion downslope of the
y N
dischar e oint duringthe peak flow from the 10 year storm.
or
G. Variations — the project has variations from the MDC that were not
N
I y
previously approved. Modification may be required)
or
H. Deed restrictions (if required) — are recorded and ensure that the
project and the 13UA will be maintained in perpetuity consistent with
Y or N
the permit, approved plans andspecifications.
I. For Subdivisions Only (Residential or Commercial)
1. The number of platted lots is consistent with the approved plans.
Y or N
2. The project area is consistent with the approved plans.
Y or N
3. The layout of the lots and streets is consistent with the approved
N'or
plan.
4. The width / radius of streets, paved accesses, cul-de-sacs and
Y N
sidewalks is consistent with the approved plan.
or
5. No piping, other than those minimum amounts needed under a
Y N
drivewav or under a road has been added.
or
6. The lot grading, road grading, vegetated conveyances, piping
NII
inverts, and elevations are consistent with the approved plans.
or
Provide an explanation for every MDC that was not met, or for every deviation from the permitted
condition below:
Page 8 of 8

Attachment 1 - Permitting History
Hurst Hamilton Parking Lots
Permit No. SW8 060530
Approval
Permit Action
RIMS
Description of the Changes
Date
Version
6/1612006
Original Approval
1.0
* Adding 13UA for the Cross-City"Dail and 80,400 sf of future 1311A allocation
5/14/2010
Modification
1.1
* Revised drainage area boundary
* The construction of two additional parking lots subject to the 2017 Rules.
2/23/2018
Major Modification
1.2
* Expanding the wet pond to Handle the increased runoff, which has been
designed per the 2017 MDC.
Page 1 of 1

0
DEMLR USE ONLY
• Date Received
Fee Paid
Permit Number
I
loa r4
154 o
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 M mt 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.):
UNC Wilmington - Hurst Hamilton Parking Lots
2. Location of Project (street address):
Hurst Drive and Wagoner Drive
City: Wilmington County: New Hanover Zip: 28403
3. Directions to project (from nearest major intersection):
Project is located at the NW corner of the intersection of Hurst Drive and Hamilton Drive and NE of
Hamilton Drive and MacMillan Avenue
4. Latitude: 34' 13' 16" N Longitude: 77' 52' 47" W of the main entrance to the project.
11. PERMIT INFORMATION:
1. a. Specify whether project is (check one): ❑New ®Modification ❑ Renewal w/ Modificationt
tRenewals mith modifications also requires SWU-102 - Reneuial Application Form
b.If this application is being submitted as the result of a modification to an existing permit, list the existing
permit numberSW8 060530 , its issue date (if known)May 14, 2010 , 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, and the previous name of the project, if different than currently
proposed, CC ^` r
4. a. Additional Pioject Requirements (check applicable blanks; information on required sta dab ILK
En
obtained by contacting the Customer Service Center at 1-877-623-6748):
❑LAMA Major ®Sedimentation/Erosion Control: 9.75 ac of Dist ed 9 B c018
❑NPDES Industrial Stormwater ❑404/401 Permit: Proposed Impacts
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:UNC Wilmington - Hurst Parking Lots - Modification/NEWHA-2018-
5. Is the project located within 5 miles of a public airport? []No ®Yes
If yes, see S.L. 2012-200, Part VI: http://portal.ncdenr.org/web/Ir/rules-and-regulations
Form SWU-101 Version Oct. 31, 2013 Page I of

f�,r; :: � �,a,.

III10Mi1tlSr IJIto]L41
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: UNC Wilmington
Signing Official & Title: Mark Morgan / Associate Vice Chancellor for Business Affairs -Facilities
b.Contact information for person listed in item la above:
Street Address:601 S. College Road
City:Wilmington State:NC Zip:29403
Mailing Address (if applicable):
City:
Phone: ( 910 1 962-3761
Email: [e-mail]
State: Zip:
Fax: (910 ) 962-7140
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 Owner's 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:
Signing Official &
b.Contact information for person listed in item 2a above:
Street Address:
Mailing Address (if applicable):
Phone: ( 1 Fax:
Email:
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:UNC Wilmington
Signing Official & Title:Galen Jamison, PE / Project Manager
b.Contact information for person listed in item 3a above:
Mailing Address:601 South College Road
City: W ilmington
Phone: (910 ) 962-2677
Email: isongflunc w. ed u
4. Local jurisdiction for building permits:
Point of Contact:
Form SWU-101 Version Oct. 31, 2013 Page 2 of 6

r WZ%zzY.-

IV. , PROJECT INFORMATION
1. In the space provided below, briefly summarize how the stormwater runoff will be treated.
Development onsite consists of the construction of two new parking lots Impervious created from the
construction of the lots will be directed into the existing regional stormwater Rood, which is to be modified
from the construction of this project.
2. a. If claiming vested rights, identify the supporting documents provided and the date they were approved:
❑ Approval of a Site Specific Development Plan or PUD Approval Date:
❑ Valid Building Permit Issued Date:
❑ Other: natp.
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: 26.81 acres 5. Total Coastal Wetlands Area: 0 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':26.81 acres
Total project area shall be calculated to exclude the following the normal pool of im ounded structures, the area
between the banks of streams and rivers, the area below the Normal High Water (NSW) line or Mean High Water
(MHW) line, and coastal wetlands landward from the NHW (or MHW) line. The resultant project area is used to
calculate overall percent built upon area (BLIA). Non -coastal wetlands landward of the NHW (or MHW) line may
be included in the total project area.
8. Project percent of impervious area: (Total Impervious Area / Total Project Area) X 100 = 49.75
9. How many drainage areas does the project have?7 (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
Stream Name
Draina e Area
DrainageReceiving
Stream ClassStream
Index Number
4Drainae
Total Drainage Area (so
On -site Drainage Area (so
Off -site Drainage Area (sf)
Proposed Impervious Area** s
Impervious Area** total
Im ervious** Surface Area
Draina e Area _
Draina e Area _
Draina e Area
Draina a Area
On -site Buildings/Lots (so
_
On -site Streets (so
On -site Parking (so
1
On -site Sidewalks (so
Other on -site (so
Future (so
Off -site (so
N �
Existing BUA*** (so
Total (sf):
--
Wuu ,nucA Number can ve determined at: nttp://Portal nedenr org/weL&wq s/esu/classifications
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.
Form SWU-101 Version Oct.31, 2013 Page 3 of

Permit: SW8OW530
Protect Number: UN W-1T060
ATTACHMENT A
Drainage Area/Impervious Breakdown
Basin Information
Drainage Area to SCM
REDEVELOPMENT EXEMPTION
Drainage Area LOW DENSITY
Drainage Area TOTAL
Recewing Stream Name
Burnt Mill Creek
Burnt Mill Creek
Burnt Mill Creek
Stream Uass
q5w
GSw
C;5w
Stream Index Number
18-74-63-2
18d4-63-2
18-94.63-2
Total Drainage Area lrp
1,218,903
14,555
139,687
1,373,145
On-SWS OW530 &On-UNCW Property Drainage Area (sfl
1,030,146
14,555
121,413
1,1W,114
On-SW8060530&Off-UNCW PropertyD=inage Area lsQ
6,029
3,566
9,fi45
Off-SW8 OW530 &On-UNCW Property Drainage Area (sf)
144,959
0
14g959
Off-SW8=530&Off-VNCW Property Drainage Area isQ
32,219
0
32,719
ROW Drainage Area (sff
0
1B708
14,708
Total Proposed Impervious Area (sf)
608,289
14,555
25,145
64T,989
On-SW8060530 Proposed Impervious Area
525,153
14,555
19,746
08,520
ROW Proposed Impervious Area
0
5,399
5,399
Total% Impervious Area
49.90%
iW.0094;
18.009E
47.19%
On-SW8060530%Impervious Area
SSSM
1W.00%
35.801"
52.1814
ROW %Impervious Area
3673%
36]3%
Im"Mous Surface Area
Drainage Area to SCM
REDEVELOPMENT EXEMPTION
Drainage Area LOW DENS"
Drainage Area TOTAL
On-siteSW8060530 Buildings/Lots(s_f)
0
0
0
on -site IWO 00530 sm,eu(so
0
-
0
0
On -site SW800530 Parking(sfl
186,959
11,600
3,228
201,787
On -site SW8060530 Sidewalks lafl
IAB85
2,955
8,692
26,532
1988-2W8 Iq`5 IJ e�S
352,597
-
6,892
359.499
2008-2017 (J� ,�' -a��
5,952
-
0
5,952
SW8031039
13,154
0
13,154
SW81W405
10,428
0
10,428
Off-UNCW Procerty&Off-SWB 0W530(If) 19M.2008
(Sea6owk Syuort & rmallpation a/Collepe flGJ
9,554
-
0
9,554
Off-UNCW PmceM& On SW8 060530 (If) 1988-2008
(-- AtuaA+inon A-)
0
-
383
383
Off-UNCW Property&On-SW8060530 III Past 2017
(--Pbac illon Aye)
0
-
551
551
ROW (sff 29M 2W8
0
1,989
1,989
ROW Is_tl Post 2017
0
3,410
ROW Existing Pre 19W BUA 1.0
0
_
20,409 'X'
0
On-SIMS W530 Existing Pre-198B BUA (If)
14,260
1,806 'IE
14,260
Total (In
W0,289
14,555
647,989
•This permit unhoes reaeuelopment ereii by treating l/)W If of eaktiry P-19811 BUA, allaxiry 14,5S5 If of propauG impentausto be bypased• * p 1)
YC
Total Drainage Arta to SCM=
1,218,903
12.98
'Drainage Area
Total -Drainage Area LOW DENSITY' =
LOW DEN51"Y = iTolal Drainage
161,902
Areal lE,ating Pre-1988 BUAl
O,
Q'
Total 'Inralin9 PrN9888VA'=
2221
If
sf
Q y
'Drainage Area LOW DENSITY'=
139,07
1
1
4 u
�I
Total Permit BounearY Area
1.231,6e:
27,84
If
,bb
�U O
p[
a a,a
to
•Y • T
FEB 14 2018
BY:
2/13/2018'

11. How was the off -site impervious area listed above determined? Provide documentation.
} Projects in Union County: Contact DEMLR Central QJJice staff to check if the project is located within a Threatened &
Endangered Species watershed that maybe subject to more stringent stormwater requirements as per 15A NCAC 02B .0600.
[��Y�l Y rJ IF�t1►i! 17.�►i�Z�I.'±�t�il��]l�u (,7
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.org/web/wq/ws/su/bmp-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.ncdenr.org/web/wq/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 at http://12ortal.ncdenr.org/web/wq/ws/so/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 from http://portal.ncdenr.ory/web/wq/ws/so/statesw/forms does.
Initia
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 A114-
Form. (if required as per Part V11 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/pages/onestopexpress.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/managementfor
the project. This is required in addition to the brief summary provided in the Project
Information, item 1.
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 '/z
mile radius 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. laeN�
i. Dimensioned property/project boundary with bearings & distances. Ta
G{j. Site Layout with all BUA identified and dimensioned.k. Existing contours, proposed contours, spot elevations, finished floor elevations.I. Details of roads, drainage features, collection systems, and stormwater control meam. Wetlands delineated, or a note on the plans that none exist. (Must be delineated byqualified person. Provide documentation of qualifications and identify the person BV;
made the determination on the plans.
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).
Form SWU-101 Version Oct. 31, 2013 Page 4 of 6

p., Vegetated buffers (where required).
,9: 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: 7 Page No: 18
11. For corporations and Limited liability corporations (LLC): Provide documentation from the NC X14
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.
hgp://www.secretaly.state.nc.us/Corl2orations/CSearch.aVx
VIL 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://portal.ncdenr.org/web/ir/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.
V III. 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: Daryl Riggins, PE
Consulting Firm: McAdams
Mailing Address: 2905 Meridian Parkway
City: Durham State: NC Zip: 27713
Phone: (919 ) 361-5000
Emaii:[e-mail]
Fax: (919 ) 361-2269
IX. PROPERTY OWNER AUTHORIZATION (if Contact Information, item 2 has been filled out, complete this
section)
I, (print or hype 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 la) with (print or hype name of organization listed in
Contact Information, item la) 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.Cl� •
,CIE
1ANis201a
Form SWU-101 Version Oct. 31, 2013 Page 5 of

'As the legal property'owner f 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:
I, a Notary Public for the State of County of
do hereby certify that personally appeared
before me this _ day of and acknowledge the due execution of the application for
a stormwater permit. Witness my hand and official seal,
SEAL
My commission
X. APPLICANT'S CERTIFICATION
1, (print or type name of person listed in Contact Information, item In) Mark Morgan
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 2H ,1000 and any other applicable state stormwater requirements.
Signature: /�/� ///L= �I Date:1�/
1, -zyyC nd- si Me ((JMCier a Notary
Public for the State of County of
do hereby certify that /! {4 tk el OQ w personally appeared
efore me thisday of �` ,n r , ObLf,an� c n ledge the due exec o of the application for
a stormwater permit. Witness my hands my hand and official seal, �1/e(C!iJ
SEAL
My commission expires Z- 3- 2w/4
P
CA R O``�-
ECF-IVE�
1AN 9 6 2010
BY:_ ---
Form SWU-101 Version Oct. 31, 2013 Page 6 of

SUPPLEMENT-EZ FORM COVER PAGE
Please indicate the types, quantities and locations of SCMs that will be used on this project:
I Quantity I Location(s)
Infiltration System
Bioretention Cell
I
Wet Pond
1 1 north of Hamilton Drive between N MacMillan Ave and Hurst Drive
Sloomwater Wetland
Permeable Pavement
Sand Filter
Rainwater Harvesting
Green Roof
Level Spreader -Filter Strip
Disconnected Impervious Surface
Treatment Swale
Dry Pond
Designer information for this project:
Name and Title:
Daniel Perry, PE
Organization:
JMcAdams
Street address:
2905 Meridian Parkway
City, State, Zip:
Durham, INC 27713
Phone number(s):
[phone]
Email:
[e-mail]
Designer
2�PQF E S S/0 1.
'SEAL 9�
045425
F PAP,
.GINEE�•••�,
Signature of Designer
Z /13 //8
Date
Applicant:
Project Name:
UNCW Hurst Hamilton Parking Lots
Address
601 South College Road
City / Town
Wilmington, NC
CnNra mr
ouaury
Company:
UNC Wilmington
Contact:
Mark Morgan/Assoc. Vice Chancelor of Business Affairs
Mailing Address:
601 S. College Road
City, State, Zip:
Wilmington, NC 28403
Phone number(s):
[phone] Fax: [phone]
Email:
[e-mail]
Certification Statement:
I certify, under penalty of law: that this Supplement-EZ form and all supporting
information were prepared under my direction or supervision;
- that the information provided in the form is, to the best of my knowledge
and belief, true, accurate, and complete; and
that the engineering plans, specifications, operation and maintenance
agreements and other supporting information are consistent with
the information provided here.
I am aware that there are significant penalties for submitting false
information including the possibility of fines and imprisonment for knowing
violations as well as a report being made to my professional board.
FEB 141118
By: -
Cover Page 1 3:36 PM 2/9/2018

3 03:x

WET POND
UNCW Hurst Hamilton Parkino Lots
THE DRAINAGE AREA 1
Drainage area number
/
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
- Parking / driveway (sq ft)
492710 sf
Total surface water area (sq fl)
- Sidewalk (sq ft)
100970 at
TOW] drainage area (sq ft)
1218903 sf
- Roof (sq ft)
14609 sf
BUA associated with existing development (sq ft)
406445 at
- Roadway (sq ft)
Proposed new BUA (sq h)
201844 sf
- Other, please speedy in the comment box below (sq ft)
Percent BUA of drainage area
49.90%
Total BUA (sq ft)
608289 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater programs) that apply (please specify):
Design rainfall depth (in)
1.5 in
1995 Rules, Session Law 2006246, Session Law 2008-211, and 2017 Rules
Minimum volume required (cu ft)
61573 d
Design volume of SCM (a. R)
66951 d
GENERAL MDC FROM 02H .1050
#1 Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
#2 Is the SCM located on or near contaminated soils?
No
#8 Does the mainetenance access comply with General MDC (8)?
Yes
#3 What are the side slopes of the SCM (H:V)?
31
#9 Does the drainage easement comply with General MDC (9)?
Yes
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
#10 If the SCM is on a single family lot, tices the plat comply with General MDC (10)?
W Are the inlets, outlets, and receiving stream protected from erosion (10-year stom)?
Yes
#11 Is there an 08M Agreement that complies with General MDC (11)?
Yes
#5 Is there a a bypass for flows in excess of the design flow?
Yes
012 Is there an 08M Plan that complies with General MDC 12)?
Yes
#6 What is the method for dewatedng the SCM for maintenance?
Pump (preferred)
913 Was the SCM designed by an NC licensedprofessional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
SA/DA
#6 Width of the vegetated shelf (tees)
60 It
#1 Surface area of the main permanent pool (square feet)
31275 at
#6 Location of vegetatetl shell
Above Normal Pool
Al Volume of the main permanent pool (cubic feet)
178984 d
#6 Elevation of top of shelf (fmsl)
34,30 If
02 Average depth of the main pool (feet)
5.72It
#6 Elevation of bottom of shell final
33.30 ft
#2 Was the vegetated shelf included in the calwlalion of average depth
No
#6 Slope of vegetated shelf (H:V)
6:1
#2 Elevation of the bottom of the permanent pool (fmsl)
26.00 in
#7 Diameter of drawdown onfice (inches)
4.00 in
#2 Elevation of the top of the permanent pool (fmsq
33.30 in
#7 Drawdown time for the temporaypool (hours)
77.28 hrs
#2 Elevation of the top Of the temporary pool fmsq
34,30 in
#1 Does the onfice drawdowa from below the top surface of the permanent pool?
Yes
#3 Depth providecl for sediment storage (inches)
fi 0 in
#8 Does the pond minimize impacts to the receiving channel from the 1-yr. 24-hr storm?
Yes
#4 Are the inief(s) and outlet located in a manner that avoids short-ciraiting?
Ves
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles , that will be taken to improve the flow path'
#9 If yes, is documentation provided per Wet Pond MDC (9)1
A forebay weir spillway is located between the forebay and main pool to increase the Flow path from inlet to outlet.
#10 Is a fresh rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
76418
#11 Are the dam and embankment planted in non -dumping turf grass?
Yes
#5 Is this 15-20% Of the volume in the main pool?
No
#11 Species of turf that will be used on the dam and embankment
c Z.n eemmapiass
#5 Depth Of forebay at entrance (inches)
69.6 in
#11 Descibe the planting plan for the vegetated shell:
#5 Depth of forebay at exit (inches)
15.6 in
The vegetated shelf will be planted with six species: Joe Pye Weed, Scarlet Rose Mallow, Seashore Mallow, Woolgrass,
Giant Cutgrass, and Blue Flag Ins. All species will be planted at 24" O.C. at a minimum density of 50 plants per 200 sf.
#5 Does water Dow out of the forebay in a non -erosive manneR
Yes
#5 Clean -out depth for forebay (inches)
63.6 in
#5 Will the tomboy be cleaned out when the depth is reduced to less than the above?
Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review:
It should be noted that this SCM was previously constructed and therefore is undergoing modification to accomdate proposed development and meet cuff ant design standards. As such, the existing dam embankment will remain with modified
grading only occurring internally. The forebay percentage exceeds the volume requirement for forebay requirement staled in the MDCs, which is primarily due to the volume contrbuted by the existing forebay across Hurst Drive that is remaining
unaltered as a part of this project.
E^ C I V L DepthDepth ProposedForebayF #2 Y entrance 27.6 in
lid' Depth of Proposed Forebay n2 at exit 2].6 in
Cleanout Depth of Proposed Forebay #2 45.6 in
•Extuhng Fo boy is not being rrwdified m port of this project*
Depth of Existing Forebay at entrance 51.6 in
Depth of Existing Forebayat exit 51.6 in
BY: Cleanout Depth of Existing Forebay 36.6 in
Wet Pond 2 3:36 PM 2/9/2018

MEMORY TRANSMISSION REPORT
TIME :02-23-2018 14:04
FAX NO.1 :9103502004
NAME :Mainfax
FILE NO.
648
DATE
02.23 14:00
TO
:n 99627140
DOCUMENT PAGES
17
START TIME
02.23 14:01
END TIME
02.23 14:04
PAGES SENT
17
STATUS
OK

MEMORY TRANSMISSION REPORT
TIME :02-23-2018 14:05
FAX NO.1 :9103502004
NAME :Mainfax
FILE NO. 649
DATE 02.23 14:01
TO :n 919193612269
DOCUMENT PAGES 17
START TIME 02.23 14:04
END TIME 02.23 14:05
PAGES SENT 0
STATUS 0050

Hall, Christine
From: Hall, Christine
Sent: Monday, February 19, 2018 5:10 PM
To: 'Perry, Daniel'
Cc: Stubbs, Rebecca; Riggins, Daryl
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060S30)
Thank you for the clarification. I have finished the review and found one more thing. The response to item 2.1b and the
revised calculations no longer considers the two proposed forebays independently. When this item was discussed on
the phone, I thought it was clear that each forebay had to demonstrate that it was sized to handle 15-20 % of its
contributing drainage area or justification for the variation had to be provided per.1003(6). Third requests for
additional information are not generally granted but... Please provide calculations identifying the individual proposed
forebay size respective to its contributing drainage area and if necessary, provide justification for any variation to the
MDC.
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
[e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405
Nothing Compares..,,.
A'
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel [mailto:[e-mail]]
Sent: Monday, February 19, 2018 3:57 PM
To: Hall, Christine <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
o External email: Do not dick Imks or open attachments unless verified. Send all suspicious email as an attachment to, ,
'xd
Hi Christine,
The calculations attached to the response are associated with the existing condition of the facility to show how the
current SCM grading shakes out with the MDC methodology. The calculations in the book are what you should be
reviewing for the proposed condition. Sorry for the confusion.
Thank you,

Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361, 5000 x134 [ direct 919. 287
www.mcadamsco.com [ linkedin I twitter
2 MCA DAMS
creating eiperiences through experience
0795 [ mobile [phone] dperrvPmcadamsco.com
instaeram I join our team
From: Hall, Christine[ma IIto:[e-mail]
Sent: Monday, February 19, 2018 3:47 PM
To: Perry, Daniel <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
I've started looking at the requested information received on 2/14 for this project and am a bit confused by the pond
sizing calculations. Why are the calculations attached to the response letter different than the ones in the
binder? Which set is correct?
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
christine. hall()ncdenr.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405
Nothing Compares._
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel [mailto:[e-mail]]
Sent: Friday, February 09, 2018 1:37 PM
To: Hall, Christine <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
Much appreciated! Have a great weekend!
Daniel Perry, PE I Project Manager, Water Resources

I .
Hall, Christine
From: Perry, Daniel <[e-mail]>
Sent: Thursday, February 22, 2018 4:09 PM
To: Hall, Christine
Cc: Stubbs, Rebecca, Riggins, Daryl
Subject: RE: (External] Hurst Hamilton Parking Lot (SW8 060530)
Attachments: Narrative.pdf, SWMF-MDC-WQ Pond Calcs-POST.PDF
u External email. Do not click links or open attachments unless ver fled Send all stuspiaous email as an attachment to
Re ort5a
Christine,
Thank you for your phone call and clarification yesterday. See attached for an updated narrative and the WQ Pond Calc
Sheet showing the forebay calculatoins. Thanks for your help!
Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919, 361. 5000 x134 I direct 919. 287. 0795 1 mobile [phone] [e-mail]
www.mcadamsco.com I linkedin I twitter I instagram.I join our team
21 MCADAMS
creating experiences through experience
From: Hall, Christine[mailto:[e-mail]]
Sent: Monday, February 19, 2018 5:10 PM
To: Perry, Daniel <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>, Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
Thank you for the clarification. I have finished the review and found one more thing. The response to item 2.b and the
revised calculations no longer considers the two proposed forebays independently. When this item was discussed on
the phone, I thought it was clear that each forebay had to demonstrate that it was sized to handle 15-20 % of its
contributing drainage area or justification for the variation had to be provided per .1003(6). Third requests for
additional information are not generally granted but... Please provide calculations identifying the individual proposed
forebay size respective to its contributing drainage area and if necessary, provide justification for any variation to the
MDC.
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
christine.hall(o)ncdenr.gov
127 Cardinal Drive Ext.

Wilmington, NC 28405
'Nothing Compares
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel Imailto:[e-mail]]
Sent: Monday, February 19, 2018 3:57 PM
To: Hall, Christine <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Higgins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
o External email. Do not click links or open'attachments unless verified. Send all suspicious email4as,3an attacment
keport Spam. ' �P.1 u `t"w
Hi Christine,
The calculations attached to the response are associated with the existing condition of the facility to show how the
current SCM grading shakes out with the MDC methodology. The calculations in the book are what you should be
reviewing for the proposed condition. Sorry for the confusion.
Thank you,
Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x134 I direct 919. 287. 0795 1 mobile [phone] [e-mail]
www.mcadamsco.com I linkedin I twitter I instagram I loin our team
0 MCADAMS
creating experiences through experience
From: Hall, Christine[mailto:[e-mail]]
Sent: Monday, February 19, 2018 3:47 PM
To: Perry, Daniel <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
I've started looking at the requested information received on 2/14 for this project and am a bit confused by the pond
sizing calculations. Why are the calculations attached to the response letter different than the ones in the
binder? Which set is correct?
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
2

MCADAMS
Date: February 13,2018
To: Ms. Christine Hall
Department of Environmental Quality
127 Cardinal Drive Extension
Wilmington, North Carolina 28405
I am sending you the following items:
❑ Drawings ❑ Letter
❑ Specifications ® Submittal
❑ Plans ❑ Prints
LETTER OF TRANSMITTAL
FEDERAL EXPRESS
Re: Hamilton Hurst Parking Lot
3rd Express Review Submittal
Job #: UNW-17060
❑ Statement of Qualifications
❑ Other
QUANTITY
UNIT
DESCRIPTION
1
Copy
Response to Comments Letter
i
Copy
Stormwater Management Plan
1
Copy
SCM Supplement Form —Original
1
Copy
O&M Manual
1
Copy
Permit Application
2
Copies
Construction Drawings
Transmitted as checked below:
M For approval
❑ For your use
❑ As requested
Remarks:
Copy to:
M For review + comment
❑ Other
❑ Other
Project Manager, Institutional
PE
creating experiences through experience 2905 Meridian Parkway, Durham, NC 27713 / 919. 361. 5000

2 MCA DAMS
February 13, 2018
State of North Carolina
Environmental Quality, Wilmington Regional Office
127 Cardinal Drive Extension
Wilmington, North Carolina 28405
RE: Hurst Hamilton Parking Lots
Stormwater Project No. SW8 060530
Request for Additional Information
UNW-17060
RESPONSE TO COMMENTS > UNW-17060
The following are the response comments for the above -mentioned project. Our response comments are in bold.
NCDEQ:
Christine Hall, Environmental Engineer 910.796. 7215
1. 15A NCAC 02H.1042(2)(g)(iv): Please provide additional proposed contours on sheets C10 and C11 to support
the identified drainage areas and patterns in the following areas:
a. The intersection of Hurst Drive and Hamilton Drive.
McAdams Response: Countour labels have been added to clarify the drainage area in this location.
Since no changes were made to this area of the site relating to this project, the drainage area remains
consistent with the previously approved permit.
b. The sidewalk high point off McMillan Ave near the pump station.
McAdams Response: The drainage area has been revised around the electric substation. Contour labels
have been provided on the existing topo and spot shots provided on the sidewalk as it meets MacMillan
Ave to better clarify drainage patterns in this area.
c. The west parking lot access drive on McMillian Ave.
McAdams Response: The draiage area has been revised and contours labels added to the proposed
grading in this area.
ECEW'1
FEB 142019 H
BY -
creating experiences through experience 2905 Meridian Parkway, Durham, NC 27713 / 919. 361. 5000

J MCADAMS RESPONSE TO COMMENTS > UNW-17060
2. 15A NCAC 02H.1053(5):.
a. The sum of the forebay drainage areas presented in the calculations is less than the total drainage area
to the pond. Please explain the difference.
McAdams Response: There are some areas within the overall drainage area to the SCM that overland
flow into the Main Pool. The size of these areas has been reduced from the existing condition in the
proposed layout, as all concentrated discharges resulting from the proposed development are directed
into one of the forebays to receive pretreatment prior to entering the main pool portion of the SCM.
b. In reviewing the calculations for sizing the individual forebay volumes, it appears that each of the three
forebays (existing and proposed) exceed 20% of its area weighted volume in the main pool. 15A NCAC
02H.1053(5)(a) requires the forebay volume to be 15 to 20% of the volume in the main pool. Please
either reconsider the size of the three forebays or provide justification for the variations in accordance
with 15A NCAC 02H.1003(6)
McAdams Response: The forebay volume provided in the SCM is in excess of the 15-20% required
volume. The existing forebay which will remain unaltered, was previously approved with a forebay volume in
excess of 20%. Attached to this reponse you will see modified calculations showing the forebay volume of the
existing forebay calculated per MDC guidance to be 52.7%. As a part of this project, additional concentrated
discharges to the SCM were required. At each of these points, a forebay of proportional size was provided to
allow for appropriate sediment dropout. The proposed forebays provide a volume within the 15-20%
requirement per the MDCs. This is in addition to the volume provided by the existing forebay. Therefore, in
total, the forebay volume well exceeds the MDC requirement, providing better opportunity got sediment
dropout prior to entering the main pool. The surface area of the main pool remains oversized, providing
better treatment of stormwater runoff directed to this SCM. Please see the attachment to this letter to show
the existing forebay % converted to MDC calculation methodology.
3. 15A NCAC 02H.1003(1)(b): In Attachment A, the exisiting, pre-1988 built upon area is not included in the total
BUA for the site. Please demonstrate that the project area used for this drainage area meets either 15A NCAC
02H.1003(1)(a) or .1003(1)(b).
McAdams Response: The project area was determined using the method described in iSA NCAC 02H
.1003 (1)(b). The existing, pre-1988 BUA in the "Drainage Area LOW DENSITY" portion of this permit
was subtracted from the total BUA and divided by the total project area within that drainage area minus
the pre-1988 BUA, to determine project density. A calculation has been provided at the bottom of
Attachment A, please refer to that document for more detail.
4. Due to the relatively minor nature of these comments, the express additional information review fee has been
waived.
McAdams Response: Thank you.
creating experiences through experience
2 of

2 MCADAMS
RESPONSE TO COMMENTS > UNW-17060
Consideration of this response is greatly appreciated. If you should have any questions or require additional
information, please do not hesitate to contact me at 919. 361. 5000.
Sincerely,
MCADAMS
Daniel Perry, PE
Project Manager, Water Resources
DP/ca
creating experiences through experience
3 of

UNCW HURSTHAMILTON PARKING LOT
STORMWATER CONTROL MEASURE
UNW-17060
SSFxn Above
NP
STAGE -STORAGE FUNCTION -ABOVE
NORMALP00L
Average
Incremental
Accumulated
Estimated
Contour
Contour
Contour
Contour
Stage
Contour
Stage
Area
Area
Volume
Volume
w/S-S Fxn
(feet)
(feet)
(SF)
(SF)
(CF)
(CF)
(feet)
33.30
0.00
53925
34.00
0.70
60103
57014
39910
39910
0.73
35.00
1.70
69180
64642
64642
104551
1.58
36.00
2.70
115911
92546
92546
197097
2.65
37.00
3.70
127573
121742
121742
318839
3.91
Storage vs. Stage
350000
300000 -
y = 59243x' zasa
250000 R' = 0.9939
LL
U 200000
m
0
150000
V
100000
50000
0
0.00 1.00 2.00 3.00 4.00
Stage (feet)
Ks = 59243
b = 1.2353
Average
Incremental
Accumulated
Estimated
1
Contour
Contour
Contour
Contour
Stage
Contour
Stage
Area
Area
Volume
Volume
w/S-S Fxn
(feet)
(feet)
(SF)
(SF)
(CF)
(CF)
(feet)
33.30
0.00
34425
34.00
0.70
38234
36330
25431
25431
0.50
35.00 1.70 43642 40938 40938 66369 1.10
37.00 3.70 132966 96328 96328 214363 2.83
Average
Incremental
Accumulated
Estimated
I
Contour
Contour
Contour
Contour
Stage
Contour
Stage
Area
Area
Volume
Volume
w/S-S Fxn
(feet)
(feet)
(SF)
(SF)
(CF)
(CF)
(feet)
33.30
0.00
19500
34.00
0.70
21869
20684
14479
14479
0.32
35.00
1.70
25S38
23704
23704
38183
0.70
36.00
2.70
56221
40880
40880
79062
1.26
37.00
3.70
70420
63321
63321
142383
2.03
R. STUBBS, El
2/9/2018
��CE1VE
` --j FEB 14 2"

UNCW HURSTHAMIJON PARKING LOT STORMWATER CONTROL MEASURE R. STu88S, El
UNW-17060 SSFxn Main Pool 2/9/2018
STAGE -STORAGE FUNCnON NIAIN'POOL
Average
Incremental
Accumulated
Estimated
Contour
Contour
Contour
Contour
Stage
Contour Stage Area
Area
Volume
Volume
w/S-S Fxn
(feet) (feet) (SF)
(SF)
(CF)
(CF)
(feet)
26.00
27.00
-1.00
0.00
2,763
4,048
Sediment Storage
28.00
1.00
5,499
4774
4774
4774
1.11
29.00
2.00
7,338
6419
6419
11192
1.89
30.00
3.00
9,823
8581
8581
19773
2.70
31.00
4.00
14,433
12128
12128
31901
3.64
32.00
5.00
24,189
19311
19311
51212
4.90
33.00
6.00
32,793
28491
28491
79703
6.46
33.30
6.30
1 34,425
33609
10083
89,785
6.97
'surface area and volume
used for avg.
depth calculation
100000
90000
Storage vs. Stage
80000
70000
Y = 4056.5x' sass
R' = 0.9817
p 60000
50000
0 40000
u 30000
20000
10000
0
2.00 4.00 6.00 8.00
0.00
Stage (feet)
Ks = 4056
b = 1.5956

UNCW HURSTHAMILTON PARKING LOT
STORMWATER CONTROL MEASURE
R. STUBBS, El
UN W-17060
SSFxn Foreboy
2/9/2018
'STAGE-STORAGE'FUNCTION=:FOREBAY
Estimated
Average
Incremental Accumulated
j
Contour
Contour
Contour Contour
Stage
Contour
Stage
Area
Area
Volume Volume
w/S-S Fxn
(feet)
(feet)
(SF)
(SF)
(CF) (CF)
(feet)
29.00
-1.25
9,132
Sediment Storage
30.25
0.00
11,872
30.50
1.50
12,442
12157
3039 3039
1.38
31.00
2.00
13.603
13023
6511 9551
2.1R
32.00 3.00 16,021 14812 14812 24363 3.17
33.00 4.00 18,557 17289 17289 41652 3.92
33.30 4.30 19,500 19028 5708 47360 4.13
60000
50000
Storage vs. Stage
y = 1343.5x2.5132
R2 = 0.9771
-- 40000
U
rn 30000
m
`o
H 2O000
10000
0-
1.00 2.00 3.00 4.00 5.00
0.00
Stage (feet)
Ks = 1343.5
b = 2.5132
FES 14 201a

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UN W-17060 Volume Calculation
R. STUBBS, El
2/9/2018
(TOTAL VOLUME OF FACILITY
Volume of Main Pool below Normal Pool=
89,785
cf
Volume of Forebay below Normal Pool=
47,360
cf
Total Volume Below Normal Pool =
137,145
cf
Total Volume Above Normal Pool=
318,839
cf
Total Volume of Facility=
455,984
cf
FOREBAY PERCENTAGE OF PERMANENT POOL VOLUME
Per NCDEQ Minimum Design Criteria, the forebay volume should equal
approximately 15-20% of the main pool volume.
Total Main Pool Volume = 89,785 cf
Provided Forebay Volume = 47,360 cf
Provided Forebay Volume %= 52.7%
AVERAGE DEPTH OF MAIN POOL
Volume of Main Pool at Permanent Pool =
89,785
cf
Surface Area of Main Pool at Permanent Pool =
34,425
sf
Average Depth =
2.61
ft
FEB 14 2018

UNC WILMINGTON
HURST HAMILTON PARKING LOTS
WILMINGTON, NORTH CAROLINA
STORMWATER MANAGEMENT PLAN
PROJECT NUMBER:
DESIGNED BY:
DATE
U N W-17060
DANIEL PERRY, PE
REBECCASTUBBS, El
FEBRUARY 2018
MCADAMS
2905 MERIDIAN PARKWAY
DURHAM, NORTH CAROLINA 27713
INC Llc. # C-0293
'mc;F-1*46
FEB 14 2o�a
BY:----
CAss
l/ L 9� .9

...1d .... ;
• Od2d52 =
CEvr
5p`OtE22... �y
't016111W,

TI MCADAMS
General Description
NARRATIVE > UNW-17060
UNC WILMINGTON — HURST HAMILTON PARKING LOTS
Stormwater Management Plan
Located at the intersection of Hurst Drive and Hamilton Drive, the Hurst Hamilton Parking Lots project will consist of
two (2) surface parking lots providing a total of +/- S74 spaces to accommodate visitors and students. The proposed
lots are anticipated to contain one entrance off Hurst, one exit onto Hamilton, and one two-way access to N. MacMillan
Drive. The project will include the addition of bike parking stalls, a bus shelter, along with a modification to an existing,
adjacent SCM (i.e. the Lot K pond).
The proposed project will be high density and will require a major modification to the existing State Stormwater
Management Permit (SW8 060530) In this area of the UNCW campus. The addition of the surface parking lots will
require an expansion to the existing SW8 060530 permit boundary. To better mimic the true drainage area to the
Stormwater Control Measure (SCM), the modified permit boundary will now Include existing BUA that has been
reviously unaccounted for, meaning that the SCM will be designed to provide equal or better treatment for the net
mcrease in BUA for this modified permit boundary. The amount of existing BUA that will now receive treatment credit
from the SCM is greater than the proposed amount of Impervious bypassed from the small proposed parking lot along
acMillan Ave. Additional impervious outside of the drainage area to the SCM has been calculated to remain under
the low -density threshold of 24% for the rernalning portion of the permit boundary. Please refer to the BUA map
included in section 4 of this report. The existing Lot K pond will be renovated / expanded to accommodate the proposed
increase In impervious area. As a result of the increase in BUA and expansion of the existing SCM, the wet pond design
will be modified to meet NC DEQ's Minimum Design Criteria.
The project is located within the Cape Fear River Basin, with stonnwater runofffrom the proposed project draining to
Burnt Mill Creek. According to the N.C. Division of Water Quality BasinWide Information Management System (BIMS),
the waterway is classified as C; Sw" at this location (Stream Index M 18-74-63-2).
Calculation Methodology
Rainfall data for the Wilmington, NC region is from NOAA Atlas 14. This data describes a depth -duration -
frequency (DDF) table describing rainfall depth versus time for varying return periods in the Wilmington, NC
area. These rainfall depths are input into the meteorological model within PondPack for peak flow rate
calculations. Please reference the miscellaneous site information section within this report for additional
information.
Using maps from the NRCS Web Soil Survey, the on- and off -site soils were determined to be from hydrologic
soil group (HSG) 'A' soils, 'B' soils and 'D' soils. Since the method chosen to compute both pre- and post -
development peak flow rates and runoff volumes is dependent upon the soil type, care was taken when
selecting the appropriate Soil Conservation Number (SCS CN). For this analysis, the HSGs for the site consisted
of'A'.'B'. and'D',
Within the site boundary, an approximate proportion of each soil group was determined using NRCS Web Soil
Survey. Once an approximate proportion was determined, a composite SCS CN was computed for each cover
condition.
• Land cover conditions for the site were taken from a recent aerial mapping survey prepared b w e Inc
and combined with ground truth survey prepared by Atlantic Coast Survey. Ell
FEB 2 2 2018
creating experiences through experience 2905 Meridian Par6y;-DurharK Nr7g'is. 36i. 5000

iJ MCADAMS
NARRATIVE > UNW-17060
The times of concentration are calculated using the SCS TR-55 Segmental Approach, The To flow paths are
divided into three segments: overland flow, concentrated flow, and channel flow. The travel time is then
computed for each segment, from which the overall time of concentration is determined by taking the sum of
each segmental time. PondPack Version VSi, by Bentley Systems, Inc., was used in determining the pre- & post -
development peak flow rates for the 1-, 2-, 10-, 25- and 100-year storm events, as well as routing calculations
for the modified stormwater management facility.
• The drainage ditches along Hamilton Drive and MacMillan Avenue were modeled as Interconnected ponds with
the existing SCM and with its proposed modifications. The ditches provide a significant amount of storage to
the watershed and therefore their stage storage function was determined using best available survey data.
• There are three proposed driveway culverts for entrances to the proposed parking lots. One along Hamilton
Drive and two along MacMillan Avenue. The driveway culverts were sized such that the interconnection of
ponds would balance the water surface elevation of the roadside ditches with the SCM. There is an existing
culvert under the driveway to existing substation off of MacMillan Avenue that was modeled, and performance
verified In throughout this analysis.
( 1 • The offsite drainage area from the adjacent apartment complex was assumed to be full build -out in the
calculation of impervious area to the SCM. If new development were proposed for the site, a 20' setback
mentioned in the ordinance would be required similar to that currently provided for this property; therefore,
this development has reached Its impervious threshold which could drain to the SCM.
• There is an existing 42" RCP culvert at the intersection of S College Rd and MacMillan Ave that was used as the
overall point of analysis In the existing and proposed scenarios of the drainage ditches and SCM. This culvert
was modeled with a tallwater condition to match crown of pipe to be conservative in the analysis of conveyance
through the pipe.
• The existing forebay of the wet detention basin will not be modified and therefore was modeled with the same
stage storage function in both the existing conditions analysis and the proposed modifications analysis. To
provide an accurate analysis of current conditions of the existing forebay, a stage storage function was
generated from survey prepared by Avioimage.
It is acknowledged that the forebay percentage in the proposed build -out condition exceeds the volume
requirement for forebays stated in the MDCs. The existing forebay which will remain unaltered, was previously
approved with a forebay volume in excess of 20%. As a part of this project, additional concentrated discharges
to the SCM were required. Project elements such as location of the concentrated discharges and physical shape
of the SCM influenced the size and location of the proposed forebays. For instance, Proposed Forebay #1.
utilizes a berm that will be constructed as part of the construction access to the west lot and will be converted
to a permanent forebay berm for the lifetime of the SCM. Additionally, a large forebay in this location is more
effective to capture the concentrated discharges from both inlets draining the east parking lot. Proposed
Forebay #2 also exceeds the 20% requirement, however, it was in the engineer's opinion that a smaller forebay
than what was designed would not be as constructible and may require more frequent sediment cleanouts.
Each of the forebays provided are proportional in size to the drainage areas directed to them. This Is in addition
to the volume provided by the existing forebay, therefore in total the forebay volume well exceeds the MDCs
requirement. The surface area of the main pool remains oversized, providing better treatment of stormwater
runoff directed to this SCM.
\ �'"�` 'The existing:obtlet structure will remain, with modifications to account for additional water quality volume
Q storage. The ouflet structure information was provided to the John R. McAdams company by survey perfor med
.4
creating experiences through experience - 2905 Meridian Parkway. Durham, NC 1919. 361. 5000

gill
MCADAMS
NARRATIVE > UNW-17060
by Atlantic Coast Survey. It is important to note that between the as -built survey conducted In 2006 and the
survey performed by Atlantic Coast survey in 2017, the reference datum was adjusted from NAVD29 to
NAVD88. This datum shift accounts for the discrepancies in elevation information between the as -built survey
and the current project survey of the outlet structure.
Conclusion
If the development on this tract is built as proposed within this report, then the applicable requirements will be met
with the proposed storinwater management facility. However, modifications to the proposed development may
require that this analysis be revised. Some modifications that would require this analysis to be revised include:
1. The proposed site impervious surface exceeds the amount accounted for In this report.
2. The watershed breaks change significantly from those used to prepare this report.
The above modifications may result in the assumptions within this report becoming invalid. The computations within
this report will need to be revisited if any of the above conditions become apparent as development of the proposed
site moves forward.
EGEI V IG
FEB 2 2 2018
BY: _ ---
creating experiences through experience 2905 Meridian Parkway. Durham, NC / 919. 361. 5000

Permit: SW8060530 ATTACHMENT A
z/u/zole
Project Number: UN W-12060
0r0inoge Area/Impervious Breakdown
Basin Information
Drainage AreatoKM
REDEVELOPMENT EXEMPTION
Drainage Area LOW DENS"
Drainage Area TOTAL
Receiving Stream Name
Burnt Mill Creek
Burnt Mill Creek
Burnt Mill Creek
Stream Class
CSw
C;Sw
CSw
Stream Index Number
18-74-63-2
18-74-63 2
I8-74-63 2
Total Oralnage Area ls_fi
1,218,903
14,555
139,687
1,373,145
On-SW8060530&On-UNCW PropeM Drain age Are.(sf)
On-SW8060530&Off-UNCW PropeM Drainage Area (If)
Off -SW8060530 &On UNCW Property Drainage Area(sfl
1,030,146
14,555
121,413
1,166,114
6,029
3,566
9,645
144,959
0
144,959
Off-SW8060530&Off-UNCW PmpeM Drainage Area is_f)
37,219
0
33,719
ROW Drainage Area (0)
0
14,208
14,708
Total stationed Impervious Area isfi
608,289
14,555
25,145
647,999
On-SW8060530 Proposed Impervious Area
575,153
14,555
1919,746
608,520
ROW Proposed lmperylous Area
0
-
5,399
5,399
TOG[%Impervious Area
49,90%
1C0.00%
1&00%
47.19%
0nSW8050530%lmteryioun Area
55.5014
100.00%
15.80%
52.18%
ROW% Impervious Area
36]3%
36.71%
Impervlous Surface Area
Drainage Area to KM
REDEVELOPMENT EXEMPTION
Drainage Area LOW DENSITY
Drainage Area TOTAL
0n site SW8060530 Buildings/LOU(ntl
0
0
0
On site SW8060530 Streets isfi
0
0
0
On -site SW8060530 Parking isfi
186,959
11,600
3,228
201,787
On- site SW8060530 Sidewalks isfi
14,885
2,955
8,692
26.532
1988-2008
352,597
-
6,892
359,489
200E-2013
5,952
-
0
5,952
SW8031039
13,154
0
13,154
SWa 300405
10p28
0
10,428
Off-UNCW Property &Off-SW806053011119M 2009
(5eobowl spuore & amaN pmlm o/Cortme Rd)
9554
-
0
9,554
Off UNC IPmperty 6 On'SWB 060530 isfi 1998-2008
favoun..'Aillon Aye)
0
383
383
Off UNCW ProteM & On-sW8060530 (IN Post 2017
(ovma MaA411on Aye)
0
-
551
551
ROW (0)1988-2008
0
1,989
1,989
ROW(sQ Post 2017
O
3,410
3,410
ROW Existing Pre-19811 BUA in_f)
0
20,409
0
On-5W80W530 Existing Pre-1988 BUA (fill14,T60
1
1.806
14,760
Total(sqj
6081289
1 14,555
25,145
642,989
-This permit utilizes rear eament exemption by Imating 14,70 IT of existing Pre 19M BUA alloym, 14,555 If of proposed impervious to be bypassed'
Total Drainage Area to SCM= 1,218,903
22.98
'Drainage Area LOW DENSITY' _ (Total Drainage Areal -[Existing Pre-1988 BUA[
Total "Drainage Area LOW OENSIN"= 161,902 If
Total-&istmg Pre 109 BUA '= 22,215 If
'Drainage Area LOW DENSITY'= 139,682 If
Total Permit Boundary Area= 1,212,682
22.94

UNCW HURST HAMILTON PARKING LOTS Attachment B R. STUBBS, El
UN W-17060 SW8 060530 Permit Boundary 2/9/2018
Point
1
Northing
173614.3524
Easting
2338018.013
2
173551.6309
2337986.431
3
173523.1011
2338009.813
4
173477.8453
2338046.902
5
173457.3113
2338064.923
6
173418.3321
2 338104.22 3
7
173388.1056
2338128.879
8
173356.2498
2338151.488
9
173325.6648
2338154.02
10
173321.0007
2338165.02
11
173326.1876
2338181.018
12
173283.7679
2338211.615
13
173 228.8061
23 382 50.022
14
173202.1854
2338262.634
15
173183.9206
2338276.657
16
173162.5925
2338302.562
17
173149.1343
2338321.541
18
173128.6557
2338352.24
19
173135.7201
2 33 8363.42 2
20
173145.1592
2338374.125
21
173174.5574
2338433.889
22
173035.5778
2338650.05
23
173050.275
2338666.617
24
173086.963
2338688.792
25
173126.7
2338710.72
26
173171.15
2338735.654
27
173215.119
2338760.154
28
173246.555
2338777.688
29
173317.5487
2338816.729
30
173349.657
2338834.606
31
173394.419
2338859.493
32
173440.884
2338885.297
33
173487.276
2338911.19
34
173530.446
2338935.226
35
173574.7259
2338959.795

UNCW HURST HAMILTON PARKING LOTS Attachment B R. STUBBS, El
UNW-17060 SW8 060530 Permit Boundary 2/9/2018
Point
36
Northing
173586.8484
Easting
2338965.131
37
17 3596.1651
2338955.39
38
173634.6391
2338976.854
39
173621.5874
2339002.365
40
173 656.2801
2 33 9020.57
2
41
173679.6085
2338995.677
42
173695.1705
2338964.066
43
173 704.601
2338961.913
44
173703.6307
2338982.544
45
173697.8086
2338993.625
46
173697.367
2338997.171
47
174192.1105
2339264.52
48
1742 24.4251
2339265.891
49
174247.9494
2339229.919
50
174259.5502
2339212.606
51
17427 5.2491
2339200.09
52
174283.3214
2339195.042
53
174308.32
71
2 33 9147.936
54
174271.6218
2339129.496
55
174268.2436
2339126.213
56
174265.3885
2339123.439
57
174262.4074
2339112.14
58
174263.4914
2339091.349
59
174251.5669
2339082.942
60
174257.0028
2339063.762
61
174257.2739
2339046.949
62
174267.482
2339029.05
63
174301.3921
2338990.802
64
174311.6483
2338985.671
65
174328.3896
2338986.96
66
174470.1399
2339065.248
67
174475.1628
2339055.842
68
174497.3755
2339067.553
69
174527.6788
2339015.126
70
174598.935
2338886.495

UNCW HURST HAMILTON PARKING LOTS Attachment B R. STUBBS, El
U N W-17060 2/9/2018
OSWS 060530 Permit Boundary
Point
71
Northing
174669.8453
2338760.735
72
174655.3846
2338752.581
73
174652.63
2338742.46
74
174672.0001
2338708.643
75
174686.8859
2338705.953
76
174680.3946
2338682.005
77
174627.6809
2338575.698
78
174561.0585
2338482.735
79
174474.0516
2338396.315
80
174381.6797
2338314.097
81
174276.3425
2338235.706
82
174188.2818
2338211.33
83
174131.8014
2338178.128
84
174107.2665
2338185.416
85
174055.9475
2338288.51
86
173995.9768
2338308.39
87
173994.1492
2338282.877
88
174006.1218
2338258.137
89
174034.1257
2338218.619
90
174048.3
241
23 38197.953
91
17407 3.5891
2338146.159
92
174122.9122
2338050.034
93
174122.2639
2338049.289
94
174071.3467
2338020.394
95
173962.3523
2337958.489
96
173877.3673
2338131.771
97
173808.2846
2338272.867
98
173917.3186
2338334.452
99
173840.7622
2338490.01
100
173621.1446
2338370.853
101
173853.6611
233789 6.7
59
102
173799.9257
2337866.242

SUMMARY OF RESULTS
1
MISCELLANEOUS SITE INFORMATION
2
PREVIOUS STATE WATER PERMITS
PRE -DEVELOPMENT HYDROLOGIC
4
CALCULATIONS
POST -DEVELOPMENT HYDROLOGIC
5
CALCULATIONS
STORMWATER MANAGEMENT FACILITY
6
DESIGN CALCULATIONS

UNCW - HURST HAM ILTON PARKING LOTS SUMMARY OF RESULTS R. STUBBS, El
UNW-17060 2/9/2018
RELEASE RATE MANAGEMENT RESULTS
EXISTING CONDITIONS PROPOSED CONDITIONS
Ditch #1
Return Period
Max WSE I
Ikl I
1-Year
36.11
2-Year
36.55
10-Year
37.10
25-Year
37.22
50-Year
37.25
300-Year
37.25
Ditch #6
Return Period
Max WSE
Ik] I
1-Year
35.72
2-Year
36.31
10-Year
37.01
25-Year
37.06
50-Year
37.12
100-Year
37.18
Ditch #2
Return Period
II
Max WSE I
Ihl I
1-Year
36.11
2-Year
36.55
30-Year
_
37.11
25-Year
37.24
50-Year
37.25
300-Year
37.25
Ditch #3
Return Period
Max WSE I
fhl �
1-Year
36.10
2-Year
_
36.53
10-Year
37.00
25-Year
37.09
50-Year
37.12
100-Year
37.14

UNCW - HURST HAM I JON PARKING LOTS SUMMARY OF RESULTS R. STUBBS, El
UNW-17060 2/9/2018
ORELEASE RATE MANAGEMENT RESULTS
EXISTING CONDITIONS
Ditch R7
Return Period
Max WSE
[hl
1-Year
35.72
2-Year
36.30
10-Year
36.63
25-Year
36.78
50-Year
36.89
100-Year
36.93
Pre-Forebay
Return Period
Max. WSE
[el
Freeboard)
Ikl
1-Year
35.70
1.30
2-Year
36.30
0.70
30-Year
36.66
0.34
25-Year
36.87
0.13
50-Year
37.02
-0.02
100-Year
37.06
-0.06
Pre -Main Pool
Return Period
Max. WSE
hl
Freeboard'
Ikl
1-Year
35.70
1.30
2-Year
36.30
0.70
10-Year
36.64
0.36
25-Year
36.80
0.20
50-Year
36.92
0.08
300-Year
36.97
0.03
PROPOSED CONDITIONS
Ditch N4
Return Period
Max WSE
Ikl
1-Year
36.09
2-Year
36.53
10-Year
36.86
25-Year
36.98
50-Year
37.00
300-Year
37.02
Ditch N5
Return Period
Max WSE
Ikl
1-Year
36.09
2-Year
36.51
10-Year
36.65
25-Year
36.71
50-Year
36.72
100-Year
36.74
Post-Forebay
Return Period
Max. WSE
IN
Freeboard
[h]
1-Year
36.09
0.91
2-Year
36.53
0.47
10-Year
36.92
0.08
25-Year
37.04
-0.04
50-Year
37.07
-0.07
100-Year
37.11
-0.11
Post -Main Pool
Return Period
Max. WSE
fhl
Freeboard
fkl I
1-Year
36.09
0.91
_
2-Year
36.53
0.47
10-Year
36.88
0.12
25-Year
37.00
0.00
SO -Year
37.02
-0.02
300-Year
37.04
-0.04

UNCW - HURST HAMILTON PARKING LOTS SUMMARY OF RESULTS
UNW-17060 SCM - Existing
STORMWATER CONTROL MEASURE SUMMARY
Design Drainage Area = 24.77 ac
Design Impervious Area = 9.35 ac
% Impervious = 37.7%
Top of Dam =
37.00
ft
NWSE=
33.30
ft
Surface Area at NWSE =
53,925
sf
WC. Orifice Diameter =
4.00
in
WQ Orifice Elevation =
33.30
ft
Number of Orifices =
2
Area Orifice #1 Area =
1.29
sf
Area Orifice #1 Top Elevation =
34.39
ft
Area Orifice #1 Invert Elevation =
33.96
ft
Number of Orifices =
1
Area Orifice #2 Area =
3.69
sf
Area Orifice #2 Top Elevation =
34.37
ft
Area Orifice #2 Invert Elevation =
33.96
ft
Riser Size =
6' x 10'
Riser Crest =
35.56
ft
Barrel Diameter=
24
in
# of Barrels =
3
Upstream Invert=
33.75
ft
Downstream Invert=
33.25
ft
Length =
42
ft
Slope =
0.0119
ft/ft
R. STUBBS, El
2/9/2018

UNCW - HURST HAMILTON PARKING LOTS SUMMARY OF RESULTS
UNW-17060 SCM - Modified
STORMWATER CONTROL MEASURE SUMMARY
Design Drainage Area = 27.98 ac
Design Impervious Area = 13.96 ac
`Y Impervious = 49.9%
Top of Dam =
37.00
ft
NWSE=
33.30
ft
WQ Storm Depth =
0.96
ft
WQ Volume=
61,573
cf
WQ Volume Elevation =
34.26
ft
Surface Area at NWSE =
31,275
sf
WQ Orifice Diameter =
4.00
in
WQ Orifice Elevation =
33.30
ft
Number of Orifices =
2
Area Orifice #1 Area =
1.50
sf
Area Orifice #1 Top Elevation =
34.80
ft
Area Orifice #1 Invert Elevation =
34.30
ft
Number of Orifices =
1
Area Orifice N2 Area =
4.50
sf
Area Orifice fit Top Elevation =
34.80
ft
Area Orifice k2 Invert Elevation =
34.30
ft
Riser Size =
6' x 10'
Riser Crest =
35.56
ft
Barrel Diameter =
24
in
# of Barrels =
3
Upstream Invert =
33.75
ft
Downstream Invert =
33.25
ft
Length =
42
ft
Slope =
0.0119
ft/ft
R. STUBBS, El
2/9/2018

O
MISCELLANEOUS SITE INFORMATION
UNCW - HURST HAMILTON PARKING LOTS
UNW-17060

UNCW PROPERTY
h.
UNC WILMINGTO
SITE AERIAL MAP
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mmmmmmzz:� Feet PROJECT#: UNW-17060
I inch 200 fim WILMINGTON, NORTH CAROLINJ
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2,000 feet
WILMINGTON, NORTH CAROLINA

NC DENR- DIVISON OF WATER RESOURCES
.0311 CAPE FEAR RIVER BASIN
2B.0300
Name of Stream
Description
Class
Class Date
Index No.
Creek
From source to Northeast Cape Fear
C;Sw
09/01/74
18-74-60
River
Northeast Cape Fear River
From mouth of Ness Creek to Cape
SC;Sw
04/01/59
18-74-(61)
Fear River
Ness Creek
From source to Northeast Cape Fear
C;Sw
09/01/74
18-74-62
River
Smith Creek
From source to Northeast Cape Fear
C;Sw
09/01/74
18-74-63
River
Spring Branch
From source to Smith Creek
C;Sw
09/O1174
18-74-63-1
.,Burnt Mill Creek
From source to Smith Creek
C;Sw
03/01/77
18-74-63-2�
Mineral Springs Branch
From source to Burnt Mill Creek
C;Sw
08/O1/85
18-74-63-2-1
Alligator Creek
From source to Cape Fear River
SC;Sw
04/O1/59
18-75
Greenfield Creek
From Greenfield Lake to Cape Fear
SC;Sw
04/01/59
18-76
River
Greenfield Lake
Entire Lake
C;Sw
04/01/59
18-76-1
Silver Stream Branch
From source to Greenfield Lake,
C;Sw
04/01/59
18-76-1-1
Greenfield Creek
Clay Bottom Branch
From source to Greenfield Lake,
C;Sw
04/01/59
18-76-1-2
Greenfield Creek
Jumping Run Branch
From source to Greenfield Lake,
C;Sw
04/01/59
18-76-1-3
Greenfield Creek
Squash Branch
From source to Greenfield Lake,
C;Sw
04/01/59
18-76-1-4
Greenfield Creek
swick River
From source to Cape Fear River
SC
08/09/81
18-77
Sturgeon Creek
From source to Burnswick River
C;Sw
04/01/59
18-77-1
Mill Creek
From source to Sturgeon Creek
C;Sw
04/01/59
18-77-1-1
Rowell Branch
From source to Mill Creek
C;Sw
04/01/59
18-77-1-1-1
Banton Branch
From source to Mill Creek
C;Sw
04/01/59
18-77-1-1-2
Redmond Creek
From source to Brunswick River
SC;Sw
04/01/59
18-77-2
Jackeys Creek
From source to Brunswick River
C;Sw
04/01/59
18-77-3
Piney Branch
From source to Jackeys Creek
C;Sw
04/01/59
18-77-3-1
Mallory Creek
From source to Cape Fear River
C;Sw
04/01/59
18-78
Little Mallory Creek (Beaverdam
From source to Mallory Creek
C;Sw
04/01/59
18-78-1
Branch)
Bamards Creek
From source to Cape Fear River
C;Sw
04/01/59
18-80
Town Creek (Rattlesnake
From source to Cape Fear River
C;Sw
09/01/74
18-81
Branch)
Turkey Branch
From source to Town Creek
C;Sw
04/01/59
18-81-1
Lewis Swamp
From source to Town Creek
C;Sw
09/01/74
18-81-2
Tompkins Branch (Tomolin
From source to Lewis Swamp
C;Sw
09/01/74
18-81-2-1
Branch)
Lewis Branch
From source to Lewis Swamp
C;Sw
09/01/74
18-81-2-2
' erdam Swamp
From source to Town Creek
C;Sw
09/01/74
18-81-3
r,__, Creek
From source to Town Creek
C;Sw
04/01/59
18-81-4
Russells Creek
From source to Town Creek
C;Sw
09/01/74
18-81-5
47

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12/22/2016 Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Wilmington, North Carolina, USA*
Latitude: 34.2227°, Longitude:-77.8652' E
Elevation: 35.37 fP" }
'source. ESRI Maps „mow
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T Parzybok, M.Yekta, and O. Riley
NOAA, National Nkather Sew e, 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
Average recurrence interval (years)
Duration
1
2
5
F-�������
10
25
50
100
200
500
1000
00-0.
0.728
02-0,
0.995
1.16
1.-1
1.-1
5-r11in
(0489-0.565)
89-0.
(0.560-0.670)
(0678-0783)
(0752-0872)
46-0.
(0.846-0.982)
(0.914-1.07)
84-1
(0984-1.16)
(1.05-124)
(113-136)
(120-145)
0.637
0.995
1.17
1.30
1.46
1.58
1.71
1.83
1.99
2.12
10-min
(0782-0902)
(0928-1.07)
(1.09-1.25)
(120-139)
(135-156)
(146-1.70)
(1.56-1.84)
( 1.67-1.97 )
( 1.79-215 )
( 189-229 )
1.05
1.25
1.46
1.64
1.85
2.01
2 16-IF
2.31
2.51
2.66
15-min
(0.977-113)
(117-135)
(137-159)
(152-176)
(1.71-1.98)
(184-215)
(198-232)
(2.10-2.49)
( 2.26-2.71)
( 237-2.87)
1.43
1.73
2.10
2.38
2.74
3.02
3.31
3.60
4.-
4.31
30-min
(134-154)
(1.61-1.86)
(1.95-225)
(221-256)
(253-294)
(2.78-3.24)
( 3.03-3.55)
( 3.27-387)
( 359-431)
( 384-466 )
1.79
2.17
2.69
3.10
3.65
4.09
4.56
5.05
5.73
6.29
60-min
(167-193)
(202-233)
(250-289)
(287-333)
(3.37-3.91)
(3.76-4.39)
(417-489)
(459-543)
(516-618)
(561-6.79)
2 -
2.57
3.28
3.87
4.72
5.45
6.24
7.11
8.39
9.50
2-hr
(1.95-231)
(237-281)
(3.02-358)
(3.55-4.22)
(431-514)
(4.95-593)
(564-679 j
( e38-7.72 )
( 745-9.13 j
( 836-104 )
2.25
2.74
3.51
4.17
5.16
6.02
6.98
8.05
9.67
11.1
3-hr
(2.08-247)
(2.53-300)
(3.23-3.84)
(3.82-456)
(470-562)
(545-656)
(627-759)
( 7.17-8.73)
( 850-10.5)
( 963-121)
2.60
3.41
4.37
5.20
6.46
7.55
8.79
10.2
12.3
14.1
6•hr
(2.59-308)
(3.15-375)
(4.02-479)
1 (4.77-5.70)
1 (588-7.04)
(6.83-8.24)
(789-957)
(903-111)
(10.8-13.4)
(12.3-154)
3.28
3.99
5.15
6.17
7.70
9.07
10.6
12.4
15.1
17.5
12-hr
(3.00-363)
(365-441)
(4.70-5.68)
(5.60-6.79)
(694-846)
(812-994)
(943-116)
(10.9-13.5 )
( 13.1-16.5 )
( 149-191 )
3.88
4.70
6.09
7.31
9.18
10.9
12.8
14.9
-IF213
24•hr
(353-4.32)
(4.29-525)
(5.54-6.78)
(663-8.12)
(825-102)
(966-12.0)
(11.2-14.2)
(12.9-16.6)
(155-205)
(178-239)
4.60
F 5.56
7.13
8.51
1067F
124-IF
14.5
16.9
20.5
23.7
24ay
(421-5.09)
(5.09-6.15)
(6.51-7.90)
(773-9.42)
(954-117)
(111-138)
(12.8-16.2)
( 14.7-18.9)
( 174-230)
( 198-268)
4.90
5.91
7.53
8.94
11.0
12.9
15.0
17.3
20.8
23.9
3-day
(449-541)
(542-653)
(689-8.33)
(8.14-9.88)
(997-122)
(115-143)
(132-i66)
(15.1-19.3)
(17.8-234)
(201-271)
5.20
6.26
7.94
9.37
11.5
13.3
15.4
17.7
21.1
24.2
4i1ay
F47-day-17
(477-573)
(575-6.91)
(726-8.76)
(8.54-103)
(10.4-12.7)
(120-148)
(137-171)
( 15.5-19.7)
( 182-237)
( 205-273)
5.96
7.19
9.05
10.6
12.9
14.8
16.9
19.1
22.5
25.3
7- ay
(552-651)
(665-7.84)
(835-986)
(974-115)
(118-140)
(13.4-16.1)
( 152-184)
( 170-210)
( 197-249)
( 2t8-282)
6.75
8.07
10.0
11.6
14.0
16.0
16.1
20.4
23.6
26.6
10-day
(625-7.31)
(749-8.77)
(925-109)
(107-126)
(12.8-15.2)
(14.5-174 )
( 163-197 )
( 182-223 )
( 209-262 )
( 231-29.5 )
9.01
10.7
13.1
15.0
17.8
20.0
22.5
25.0
28.7
31.7
20-day
(841969)
1 (100-116)
1 (122-141)
1 (14.0-16.1)
1 (16.5-19.1)
(184-216)
(205-24:3)
(227-272)
(25.6-31.4)
(27.9-35.0)
11.1
13.1
15.8
17.9
20.9
23.3
25.7
26.3
31.8
34.6
30-day
(104118)
1 (124-140)
1 (148-168)
1 (16.8-19.1)
1 (195-223)
(216-249)
(237-27.6)
(259-30.4)
(28.8-34.4)
(31.0-37.7)
13.8
16.3
19.4
F 21.8
F 25.2
279-17
30.7
33.5
37.4
40.4
45-day
(130147)
(15.4-174)
(18.2-20.6)
(20.5-23.2)
(236-268)
(260-297)
(28.4-32.7)
( 30.8-35.9)
( 34.0-40.3)
( 365-439)
16.6
19.5
22.8
25.5
29.0
31.8
34.5
37.3
41.0 1
43.6
60-day
(15.7-176)
(18.5-20.7)
(21.6-242)
(241-270)
(273-308)
(298-338)
(32136.8)
(34.6-39.9)
(3T7-440)
(400-473)
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 (far 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.
http://hdsc.ms.noaa.gov/hdsc/pfds/pfds_lri ntpage.htm l?tat=34.2227&Ion=-77.8652&data=depth&units=engl ish&series=pds 114

9 MCADAMS
Storm Data Detailed Report:
U N W 17060
Element Details
ID
40
Notes
Label
UNW17060
1yr24hr
Label
lyr 24hr
Increment
5.00 min
Return Event
1 years
End Time
1,440.00 min
Start Time
0.00 min
Storm Event Depth
Type
Cumulative
_
iyr 24hr
Time
Depth
Depth
Depth
Depth
Depth
'(min)
(in)
(in)
(in)
(in)
(in)
0.00
0.000
0.004
0.008
0.013
0.017
25.00
0.021
0.025
0.029
0.033
0.037
50.00
0.042
0.046
0.050
0.054
0.058
75.00
0.063
0.067
0.071
0.075
0.079
100.00
0,083
0.087
0.092
0.096
0.100
125.00
0.104
0.108
0.113
0.117
0.121
150.00
0.125
0.129
0.133
0.138
0.142
175.00
0.146
0.150
0.154
0.158
0.163
200.00
0.167
0,171
0.175
0.179
0.183
225.00
0.188
0.192
0.196
0.200
0.204
250.00
0.208
0.212
0.217
0.221
0.225
275.00
0.229
0.233
0.238
0.242
0.246
300.00
0.250
0.254
0.258
0.262
0.267
325.00
0.271
0.275
0.279
0.283
0.288
350.00
0.292
0.296
0.300
0.307
0.313
375.00
0.320
0.327
0.333
0.340
0.347
400.00
0.353
0.360
0.367
0.373
0.380
425.00
0.387
0.393
0.400
0.407
0.413
450.00
0.420
0.427
0.433
0.440
0.447
475.00
0.453
0.460
0.467
0.473
0.480
500.00
0.487
0.493
0.500
0.507
0.513
525.00
0.520
0.527
0.533
0.540
0.555
550.00
0.571
0.586
0.601
0.616
0.632
575.00
0.647
0.662
0.678
0.693
0.708
600.00
0.723
0.739
0.754
0.769
0.784
625.00
0.800
0.815
0.827
0.838
0.850
650.00
0.862
0.873
0.885
0.912
0.938
675.00
0.965
0.992
1.018
1.045
1.127
700.00
1.209
1.292
1.374
1.639
2.159
725.00
2.424
2.506
2.588
2.671
2.753
750.00
2.835
2.862
2.888
2.915
2.942
775.00
2.968
2.995
3.007
3.018
3.030
800.00
3.042
3.053
3.065
3.080
3.096
825.00
3.111
3.126
3.141
3.157
3.172
850.00
3.187
3.203
3.218
3.233
3.248
875.00
3.264
3.279
3,294
3.309
3.325
900.00
3.340
3.347
3.353
3.360
3,367
925.00
3.373
3.380
3.387
3.393
3.400
950.00
3.407
3.413
3.420
3.427
3.433
975.00
3.440
3.447
3.453
3.460
3.467
1,000.00
3.473
3.480
3.487
3.493
3.500
1,025.00
3.507
3.513
3.520
3.527
3.533
Hamilton -Hurst Parking
Lot
R. STUBBS, El
UNW17060.ppc
2/9/2018

9 MCADAMS
Storm Data Detailed Report:
U N W 17060
lyr 24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
1,050.00
3.540
3.547
.3.553
3.560
3.567
1,075.00
3.573
3.580
3.584
3.588
3.593
1,100.00
3.597
3.601
3.605
3.609
3.613
1,125.00
3.618
3.622
3.626
3.630
3.634
1,150.00
3.638
3.643
3.647
3.651
-
3.655
1,175.00
3.659
3.663
3.668
3.672
3.676
1,200.00
3.680
3.684
3.688
3.693
3.697
1,225.00
3.701
3.705
3.709
3.713
3.718
1,250.00
3.722
3.726
3.730
3.734
3.738
1,275.00
3.743
3.747
3.751
3.755
3.759
1,300.00
3.763
3.768
3.772
3.776
3.780
1,325.00
3.784
3.788
3.793
3.797
3.801
1,350.00
3.805
3.809
3.813
3.818
3.822
1,375.00
3.826
3.830
3.834
3.838
3.843
1,400.00
3.847
3.851
3.855
3.859
3.863
1,425.00
3.868
3.872
3.876
3.880
(N/A)
2yr 24hr
Label
2yr 24hr
Increment
5.00 min
Return Event
2 years
End
Time
1,440.00 min
Start Time
0.00 min
Storm Event Depth
Type
Cumulative
2yr 24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
0.00
0.000
0.005
0.010
0.015
0.020
25.00
0.025
0.030
0.035
0.039
0.044
50.00
0.049
0.054
0.059
0.064
0.069
75.00
0.074
0.079
0.084
0.089
0.094
100.00
0.099
0.104
0.108
0.113
0.118
125.00
0.123
0.128
0.133
0.138
0.143
150.00
0.148
0.153
0.156
0.163
0.168
175.00
0.173
0.178
O. 182
0.187
0.192
200.00
0.197
0.202
0.207
0.212
0.217
225.00
0.222
0.227
0.232
0.237
0.242
250.00
0.247
0.251
0.256
0.261
0.266
275.00
0.271
0.276
0.281
0.286
0.291
300.00
0,296
0.301
0.306
0.311
0.316
325.00
0.320
0.325
0.330
0.335
0.340
350.00
0.345
0.350
0.355
0.363
0.371
375.00
0.379
0.387
0.395
0.403
0.411
400.00
0.419
0.428
0.436
0.444
0.452
425.00
0.460
0.468
0.476
0.484
0.492
450.00
0.500
0.508
0.516
0.524
0.532
475.00
0.540
0.548
0.556
0.564
0.573
500.00
0.581
0.589
0.597
0.605
0.613
525.00
0.621
0.629
0.637
0.645
0.664
550.00
0.682
0.701
0.719
0.738
0.757
575.00
0.775
0.794
0.813
0.831
0.850
600.00
0.868
0.887
0.906
0.924
0.943
Hamilton -Hurst Parking Lot
R. STUBBS,
El
UN W 17060. ppc
2/9/2018

9 MCADAMS
Storm Data Detailed Report:
UNW17060
2yr 24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
625.00
0.961
0.980
0.994
1.008
1.023
650.00
1.037
1.051
1.065
1.098
1.132
675.00
1.165
1.198
1.232
1.265
1.367
700.00
1.469
1.572
1.674
1.989
2.609
725.00
2.924
3.026
3.128
3.231
3.333
750.00
3.435
3.468
3.502
3.535
3.568
775.00
3.602
3.635
3.649
3,663
3.678
800.00
3.692
3.706
3.720
3,739
3.757
825.00
3.776
3.794
3.813
3.832
3.850
850.00
3.869
3.888
3.906
3.925
3.943
875.00
3.962
3.981
3.999
4.018
4.036
900.00
4.055
4.063
4.071
4.079
4.087
925.00
4.095
4.103
4.111
4.119
4.128
950.00
4.136
4.144
4.152
4.160
4.168
975.00
4.176
4.184
4.192
4.200
4.208
1,000.00
4.216
4.224
4.232
4.240
4.248
1,025.00
4.256
4.264
4.273
4.281
4.289
1,050.00
4.297
4.305
4.313
4.321
4.329
1,075.00
4.337
4.345
4.350
4.355
4.360
1,100.00
4.365
4.370
4.375
4.380
4.384
1,125.00
4.389
4.394
4.399
4.404
4.409
1,150.00
4.414
4.419
4.424
4.429
4.434
1,175.00
4.439
4.444
4.449
4.453
4.458
1,200.00
4.463
4.468
4.473
4.478
4.483
1,225.00
4.488
4.493
4.498
4.503
4.508
1,250.00
4,513
4.518
4.523
4.527
4.532
11275.00
4.537
4.542
4.547
4.552
4.557
11300.00
4.562
4.567
4.572
4.577
4.582
11325.00
4.587
4.592
4.596
4.601
4.606
11350.00
4.611
4.616
4.621
4.626
4.631
11375.00
4.636
4.641
4.646
4.651
4.656
11400.00
4.661
4.665
4.670
4.675
4.680
1,425.00
4.685
4.690
4.695
4.700
(N/A)
10yr24hr
Label
10yr 24hr
Increment
5.00 min
Return Event
10 years
End Time
1,440.00 min
Start Time
0.00 min
Storm Event Depth
Type
Cumulative
10yr24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
0.00
0.000
0.008
0.016
0.024
0.032
25.00
0.040
0.048
0.055
0.063
0.071
50.00
0.079
0.087
0.095
0.103
0.111
75.00
0.119
0.127
0.135
0.143
0.150
100.00
0.158
0.166
0.174
0.182
0.190
125.00
0.198
0.206
0.214
0.222
0.230
150.00
0.238
0.245
0.253
0.261
0.269
175.00
0.277
0.285
0.293
0.301
0.309
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

9 MCADAMS
Storm Data Detailed Report:
U N W 17060
10yr24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
200.00
0.317
0.325
0.333
0.340
0.348
225.00
0.356
0.364
0.372
0.380
0.388
250.00
0.396
0.404
0.412
0.420
0.428
275.00
0.435
0.443
0.451
0.459
0.467
300.00
0.475
0.483
0.491
0.499
0.507
325.00
0.515
0.523
0.530
0.538
0.546
350.00
0.554
0.562
0.570
0.583
0.597
375.00
0.610
0.624
0.637
0.651
0.664
400.00
0.678
0.691
0.705
0.718
0.732
425.00
0.745
0.759
0.772
0.786
0.799
450.00
0.813
0.826
0.839
0.853
0.866
475.00
0.880
0.893
0.907
0.920
0.934
500.00
0.947
0.961
0.974
0.988
1.001
525.00
1.015
1.028
1.042
1.055
1.084
550.00
1.112
1.141
1.169
1.196
1.227
575.00
1.255
1.284
1.313
1.341
1.370
600.00
1.398
1.427
1.456
1.484
1.513
625.00
1.541
1.570
1.595
1.620
1.645
650.00
1.670
1.695
1.720
1.784
1.848
675.00
1.913
1.977
2.041
2.105
2.267
700.00
2.429
2.592
2.754
3.169
3.979
725.00
4.394
4.556
4.718
4.881
5.043
750.00
5.205
5.269
5.333
5.398
5.462
775.00
5.526
5.590
5.615
5.640
5.665
800.00
5.690
5.715
5.740
5.769
5.797
825.00
5.826
5.854
5.883
5.912
5.940
850.00
5.969
5.998
6.026
6.055
6.083
875.00
6.112
6.141
6.169
6.198
6.226
900.00
6.255
6.268
6.282
6.295
6.309
925.00
6.322
6.336
6.349
6.363
6.376
950.00
6.390
6.403
6.417
6.430
6.444
975.00
6.457
6.471
6.484
6.498
6.511
1,000.00
6.524
6.538
6.551
6.565
6.578
1,025.00
6.592
6.605
6.619
6.632
6.646
1,050.00
6.659
6.673
6.686
6.700
6.713
1,075.00
6.727
6.740
6.748
6.756
6.764
1,100.00
6.772
6.780
6.788
6.795
6,803
1,125.00
6.811
6.819
6,827
6.835
6.843
1,150.00
6.851
6.859
6.867
6.875
6.883
1,175.00
6.890
6.898
6,906
6.914
6.922
1,200.00
6.930
6.938
6.946
6.954
6.962
1,225.00
6.970
6.978
6.985
6.993
7.001
1,250.00
7.009
7.017
7.025
7.033
7.041
1,275.00
7.049
7.057
7.065
7.073
7.080
1,300.00
7.088
7.096
7.104
7.112
7.120
1,325.00
7.128
7.136
7.144
7.152
7.160
1,350.00
7.168
7.175
7.183
7.191
7.199
1,375.00
7.207
7.215
7.223
7.231
7.239
1,400.00
7.247
7.255
7.263
7.270
7.278
1,425.00
7,286
7.294
7.302
7.310
(N/A)
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppe _ 2/9/2016

9 MCADAMS
Storm Data Detailed Report:
U N W 17060
25yr 24hr
Label 25yr 24hr Increment 5.00 min
Return Event 25 years End Time 1,440.00 min
Start Time 0.00 min Storm Event Depth Type Cumulative
25yr 24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
- (in)
(in)
0.00
0.000
0.010
0.021
0.031
0.041
25.00
0.051
0.062
0.072
0.082
0.092
50.00
0.103
0.113
0.123
0.134
0.144
75.00
0.154
0.164
0.175
0.185
0.195
100.00
0.206
0.216
0.226
0.236
0.247
125.00
0.257
0.267
0.278
0.288
0.298
150.00
0.308
0.319
0.329
0.339
0.349
175.00
0.360
0.370
0.380
0.391
0.401
200.00
0.411
0.421
0.432
0.442
0.452
225.00
0.462
0.473
0.483
0.493
0.504
250.00
0.514
0.524
0.534
0.545
0.555
275.00
0.565
0.576
0.586
0.596
0.606
300.00
0.617
0.627
0.637
0.647
0.658
325.00
0.668
0.678
0.689
0.699
0.709
350.00
0.719
0.730
0.740
0.757
0.774
375.00
0.792
0.809
0.826
0.843
0.861
400.00
0.878
0.895
0.912
0.929
0.947
425.00
0.964
0.981
0.998
1.016
1.033
450.00
1.050
1.067
1.084
1.102
1.119
475.00
1.136
1.153
1.171
1.188
1.205
500.00
1.222
1,239
1.257
1.274
1.291
525.00
1.308
1.326
1.343
1.360
1.396
550.00
1.432
1.468
1.504
1.541
1.577
575.00
1.613
1.649
1,685
1.721
1.757
600.00
1.793
1.829
1,866
1.902
1.938
625.00
1.974
2.010
2.047
2.083
2.120
650.00
2.157
2.193
2.230
2.319
2.408
675.00
2.498
2.587
2.676
2.765
2.965
700.00
3.165
3.365
3.565
4.030
4.950
725.00
5.415
5.615
5.815
6.015
6.215
750.00
6.415
6.504
6.593
6.683
6.772
775.00
6.861
6.950
6.987
7.023
7.060
800.00
7.097
7.133
7.170
7.206
7.242
825.00
7.278
7.314
7.351
7.387
7.423
850.00
7.459
7.495
7.531
7.567
7.603
875.00
7.639
7.676
7.712
7.748
7.784
900.00
7.820
7.837
7.854
7.872
7.889
925.00
7.906
7.923
7.941
7.958
7.975
950.00
7.992
8.009
8.027
8.044
8.061
975.00
8.076
8.096
8.113
8.130
8.147
1,000.00
8.164
8.182
8.199
8.216
8.233
1,025.00
8.251
8.266
8.285
8.302
8.319
1,050.00
8.337
8.354
8.371
8.388
8.406
1,075.00
8.423
8.440
8.450
8.461
8.471
1,100.00
8.481
8.491
8.502
8.512
8.522
1,125.00
8.533
8,543
8.553
8.563
8.574
Hamilton -Hurst Parking Lot R. Maas, El
UNW17060.ppc 2/9/2018

'J MCADAMS
Storm Data Detailed Report:
U N W 17060
25yr24hr
Time
(min)
1,150.00
1,175.00
1,200.00
1,225.00
1,250.00
1,275.00
1,300.00
1,325.00
1,350.00
1,375.00
1,400.00
1,425.00
50yr24hr
Depth
(in)
8.584
8.635
8.687
8.738
8.789
8.841
8.892
8.944
8.995
9.046
9.098
9.149
Depth
(in)
8.594
8.646
8.697
8.748
8.800
8.851
8.903
8.954
9.005
9.057
9.108
9.159
Depth
(in)
8.604
8.656
8.707
8.759
8.810
8.861
6.913
8.964
9.016
9.067
9.118
9.170
Depth
(in)
8.615
8.666
8.718
8.769
8.820
8.872
8.923
6.974
9.026
9.077
9.129
9.180
Depth
(in)
8.625
8.676
8.728
8.779
8.831
8.882
8.933
8.985
9.036
9.088
9.139
(N/A)
Label
50yr 24hr
Increment
5.00 min
Return Event
50 years
End
Time
1,440.00 min
Start Time
0.00 min
Storm Event Depth
Type
Cumulative
50yr24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
0.00
0.000
0.012
0.025
0.037
0.050
25.00
0.062
0.075
0.087
0.099
0.112
50.00
0.124
0.137
0.149
0.162
0.174
75.00
0.186
0.199
0.211
0.224
0.236
100.00
0.249
0.261
0.273
0.286
0.298
125.00
0.311
0.323
0.336
0.348
0.360
150.00
0.373
0.385
0.398
0.410
0.423
175.00
0.435
0.448
0.460
0.472
0.485
200.00
0.497
0.510
0.522
0.535
0.547
225.00
0.559
0.572
0.584
0.597
0.609
250.00
0.622
0.634
0.646
0.659
0.671
275.00
0.684
0.696
0.709
0.721
0.733
300.00
0.746
0.758
0.771
0.783
0.796
325.00
0.808
0.820
0.833
0.845
0.858
350.00
0.870
0.883
0.895
0.916
0.937
375.00
0.958
0.979
1.001
1.022
1.043
400.00
1.064
1.085
1.106
1.127
1.148
425.00
1.169
1.191
1.212
1.233
1.254
450.00
1.275
1.296
1.317
1.338
1.359
475.00
1.381
1.402
1.423
1.444
1.465
500.00
1,486
1.507
1.528
1.549
1.571
525.00
1.592
1.613
1.634
1.655
1.698
550.00
1.740
1.783
1.825
1.868
1.910
575.00
1.953
1.995
2.038
2.080
2.123
600.00
2.165
2.208
2.250
2.293
2.335
625.00
2.378
2.420
2.468
2.515
2.563
650.00
2.610
2.658
2.705
2.818
2.932
675.00
3.045
3.158
3.272
3.385
3.616
700.00
3.847
4.078
4.309
4.819
5.809
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

9 MCADAMS
Storm Data Detailed Report:
U N W 17060
50yr24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in)
(in)
(in)
725.00
6.319
6.551
6.782
7.013
7.244
750.00
7.475
7.588
7.702
7.815
7.928
775.00
8.042
8.155
8.203
8.250
8.298
800.00
8.345
8.393
8.440
8.483
8.525
825.00
8.568
8.610
8.653
8.695
8.738
850.00
8.780
8.823
8.865
8.908
8.950
875.00
8.993
9.035
9.078
9.120
9.163
900.00
9.205
9.226
9.247
9.268
9.289
925.00
9.311
9.332
9.353
9.374
9.395
950.00
9.416
9.437
9.458
9.479
9.501
975.00
9.522
9.543
9.564
9.585
9.606
1,000.00
9.627
9.648
9.669
9.691
9.712
1,025.00
9.733
9.754
9.775
9.796
9.817
1,050.00
9.838
9.859
9.881
9.902
9.923
1,075.00
9.944
9.965
9.977
9.990
10.002
1,100.00
10.015
10.027
10.040
10.052
10.064
1,125.00
10.077
10.089
10.102
10.114
10.127
1,150.00
10.139
10.151
10.164
10.176
10.189
1,175.00
10.201
10.214
10.226
10.238
10.251
1,200.00
10.263
10.276
10.288
10.301
10.313
1,225.00
10.325
10.338
10.350
10.363
10.375
1,250.00
10.388
10.400
10.413
10.425
10.437
1,275.00
10.450
10.462
10.475
10.487
10.500
1,300.00
10.512
10.524
10.537
10.549
10.562
1,325.00
10.574
10.587
10.599
10.611
10.624
1,350.00
10.636
10.649
10.661
10.674
10.686
1,375.00
10.698
10.711
10.723
10.736
10.748
1,400.00
10.761
10.773
10.785
10.798
10.810
1,425.00
10,823
10.835
10.848
10.860
(N/A)
100yr24hr
Label 100yr 24hr Increment 5.00 min
Return Event 100 years End Time 1,440.00 min
Start Time 0.00 min Storm Event Depth Type Cumulative
100yr24hr
Time
Depth
Depth
Depth
Depth
Depth
(min)
(in)
(in)
(in) -
(in)
(in)
0.00
0.000
0.015
0.030
0.045
0.060
25.00
0.075
0.090
0.105
0.119
0.134
50.00
0.149
0.164
0.179
0.194
0.209
75.00
0.224
0.239
0.254
0.269
0.284
100.00
0.299
0.314
0.328
0.343
0.358
125.00
0.373
0.388
0.403
0.418
0.433
150.00
0.448
0.463
0.478
0.493
0.508
175.00
0.523
0.538
0.552
0.567
0.582
200.00
0.597
0.612
0.627
0.642
0.657
225.00
0.672
0.687
0.702
0.717
0.732
250.00
0.747
0.761
0.776
0.791
0.806
275.00
0.821
0.836
0.851
0.866
0.881
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc . 2/9/2018

'J MCADAMS
Storm Data Detailed Repot,
®
U N W 17060
100yr24hr
Time
Depth
Depth Depth
Depth
Depth
(min)
(in)
(in) (in)
(in)
(in)
300.00
0.896
0.911
0.926
0.941
0.956
325.00
0.970
0.985
1.000
1.015
1.030
350.00
1.045
1.060
1.075
1.100
1.126
375.00
1.151
1.176
1.201
1.227
1.252
400.00
1:277
1.303
1.328
1.353
1.378
425.00
1.404
1.429
1.454
1.479
1.505
450.00
1.530
1.555
1.581
1.606
1.631
475.00
1.656
1.682
1.707
1.732
1.758
500.00
1.783
1.808
1.833
1.859
1.884
525.00
1.909
1.934
1.960
1.985
2.035
550.00
2.086
2.136
2.186
2.236
2.287
575.00
2.337
2.387
2.438
2.488
2.538
600.00
2.588
2.639
2.689
2.739
2.789
625.00
2.840
2.890
2.952
3.013
3.075
650.00
3.137
3.198
3.260
3.400
3.540
675.00
3.680
3.820
3.960
4.100
4.367
700.00
4.633
4.900
5.167
5.707
6.787
725.00
7.327
7.593
7.860
8.127
8.393
750.00
8.660
8.800
8.940
9.080
9.220
775.00
9.360
9.500
9.562
9.623
9.685
800.00
9.747
9.808
9.870
9.920
9.971
825.00
10.021
10.071
10.121
10.172
10.222
850.00
10.272
10.323
10.373
10.423
10.473
875.00
10.524
10.574
10.624
10.674
10.725
900.00
10.775
10.800
10.826
10.851
10.876
925.00
10.901
10.927
10.952
10.977
11.003
950.00
11.028
11.053
11.078
11.104
11.129
975.00
11.154
11.179
11.205
11.230
11.255
1,000.00
11.281
11.306
11.331
11.356
11.382
1,025.00
11.407
11.432
11.458
11.483
11.508
1,050.00
11.533
11.559
11.584
11.609 -
11.634
1,075.00
11.660
11.685
11.700
11.715
11.730
1,100.00
11.745
11.760
11.775
11.790
11.804
1,125.00
11.819
11.834
11.849
11.864
11.879
1,150.00
11.894
11,909
11.924
11.939
11.954
1,175.00
11.969
11.984
11.999
12.013
12.028
1,200.00
12.043
12.058
12.073
12.088
12.103
1,225.00
12.118
12.133
12.148
12.163
12.178
1,250.00
12.193
12.208
12.223
12.237
12.252
1,275.00
12.267
12.282
12.297
12.312
12.327
1,300.00
12.342
12.357
12.372
12.387
12.402
1,325.00
12.417
12.432
12.446
12.461
12.476
1,350.00
12.491
12.506
12.521
12.536
12.551
1,375.00
12.566
12.581
12.596
12.611
12.626
1,400.00
12.641
12.655
12.670
12.685
12.700
1,425.00
12.715
12.730
12.745
12.760
(N/A)
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

MCADAMS
Storm Data Detailed Report:
UNW17060
15.000
13.750
12.500
11.250
10.000
8.750
c
t 7.500
n
v
6.250
5.000
3.750
2,500
1.250
0.000 -6�--- '
0.00 144.00 288.00 432.00 576.00 720.00 864.00 1,008.00 1,152.00 1,296.00 1,440.0(
Time (min)
100yr 24hr - 50yr 24hr - 25yr 24hr - 10yr 24hr - 2yr 24hr - lyr 24hr
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppt 2/9/2018

PRE -DEVELOPMENT
HYDROLOGIC CALCULATIONS
UNCW - HURST HAMILTON PARKING LOTS
U N W-17060

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Summary of Results 2/9/2018
(HYDROLOGY INPUT SUMMARY
Onsite Area [acres]
- Offsite Area [acres]
Total Area
Sub -basin ID
Impervious
Open
Wooded
Pond
Total
Impervious
Open
Wooded
Pond
Total
[acres]
SCS CN
Tc [min]
Main Pool
0.50
0.70
2.75
0.94
4.88
0.00
0.29
0.00
0.00
0.29
5.17
57
25.37
Forebay
8.73
9.54
0.00
0.45
18.72
0.02
0.48
0.00
0.00
0.50
19.22
74
23.41
Ditch6
5.05
11.39
14.71
0.00
31.15
0.00
0.11
0.78
0.00
0.89
32.04
58
32.66
Ditch7
0.09
0.47
1.50
0.00
2.06
0.11
0.37
0.00 1
0.00
0.48
2.54
46
25.43
Totals=
14.38 22.09 18.96 1.38 56.81
0.13 1.26 0.78 0.00 2.17
58.97

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub t0 Moin Pool 2/9/2018
1. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded !
A
98
39
30
B
96
61
55
C
9B
74
70
D
98
80
77
H5G'A'= 62.9%
HSG'B'= 37.1%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS ON
Comments
_ Impervious
98
Open
47
Assume good condition
Wooded
39
Assume good condition
II. PRE -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS ON
Area
Area acres
Comments
Onsite impervious
98
21,701
0.50
Onsite open
47
30,406
0.70
Assume good condition
Onsite wooded
39
119,710
2.75
Assume good condition
Onsite pond
100
40,773
0.94
Offsite im ewious
98
0
0.00
Offsite open
47
12,795
0.29
Assume good condition
Offsite wooded
39
0
0.00
Assume good condition
Offsite pond
100
0
0.00
Total area =
Composite SCS CN =
% Impervious =
5.17 acres
225,385 sq. ft.
57
9.6%

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY
® UNW-17060 Sub to Main Pool
III. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach lTR-551.
Segment 1: Overland Flow
Length =
100
ft
Top Elev=
38.5
ft
Bot Elev=
36.5
ft
Height=
2
it
Slope=
0.0200
ft/ft
Manning's n=
0.40
wooded, dense underbrush
P (2-year/24-hour) =
4.70
inches (Wilmington, INC)
Segment Time=
17.72
minutes
Segment 3: Pipe Flow
Length =
18
ft
Top Elev=
36
Bar Elev=
35.75
Height=
0.25
it
Slope =
0.0139
ft/ft
Manning's n=
0.013
concrete
Flow Area =
0.79
sf (assume 12" RCP)
Wetted Perimeter=
3.14
If (assume 12" RCP)
Channel Velocity=
5.36
ft/sec
Segment Time=
0.06
minutes
R. STUBBS, El
2/9/2018
Segment 2: Concentrated Flow
Length =
300
H
Tap Elev=
36.50
ft
Bot Elev=
36
ft
Height=
1
it
Slope=
0.0017
ft/ft
Paved 7=
No
Velocity=
0.66
ft/sec
Segment Time=
7.59
minutes
Time of Concentration= 25.37 minutes
SCS Lag Time= 15.22 minutes SCS Lag =0.6-Tc)
Time Increment= 4.41 minutes (=0.29-SCS tag)

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, EI
UNW-17060 Sub to Forebay 2/9/2018
I. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG'A'= 43.1%
H5G'B'= 56.9%
HSG'C'= 0.0%
H5G'D'= 0.0%
Cover Condition
SCS CN
Comments
Impervious
98
Open
52
Assume good condition
Wooded
44
Assume good condition
II. PRE -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS CN
Area [s_fl
Area' acres
Comments 1
Onsite impervious
98
380,433
8.73
Onsite open
52
415,487
9.54
Assume good condition
Onsite wooded
44
0
0.00
Assume good condition
Onsite pond
100
19,500
0.45
-
Offsite impervious
98
816
0.02
Offsite open
52
21,105
0.48
Assume good condition
Offsite wooded
44
0
0.00
Assume good condition
Offsite pond
100
0
0.00
Total area =
Composite SCS CN =
% Impervious =
19.22 acres
837,341 sq. R.
74
45.5%

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY
UNW-17060 Sub to Foreboy
III. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach (TR-55/.
Segment 1: Overland Flow
Segment 1: Concentrated Flow
Length =
100
ft
Length =
235
Top Elev=
41.0
ft
Top Elev=
40.5
Bot Elev=
40.5
ft
Bot Elev=
37.9
Height=
0.5
ft
Height=
3
Slope=
0.0050
ft/ft
Slope=
0.0111
Manning's n=
0.24
dense grass
Paved ?=
No
P (2-year/24-hour)=
4.70
inches (Wilmington, NC)
Velocity=
1.70
Segment Time=
20.50
minutes
Segment Time=
2.31
Segment 3: Pipe Flow
Length =
358
ft
Top Elev=
37.9
Bot Elev=
34.0
Height=
3.9
ft
Slope=
0.0109
ft/ft
Manning's n=
0.013
concrete
Flow Area =
1.77
sf (assume 18" RCP)
Wetted Perimeter=
2.36
If (assume 18" RCP)
Channel Velocity=
9.88
ft/sec
Segment Time=
0.60
minutes
rime of Concentration= 23.41 minutes
SCS Lag rime = 14.05 minutes (SCS Lag = 0.6` Tc)
rime Increment= 4.07 minutes (=0.29•SCS Lag)
R. STUBBS, El
2/9/2018
ft
ft
ft
ft
ft/ft
ft/sec
minutes

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Ditch6 2/9/2018
I. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
H5G'A'= 29.8%
HSG'B'= 70.2%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments
Impervious
98
Open
S4
Assume good condition
Wooded
48
Assume good condition
II. PRE -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS ON
Area [sfl
Area acres
Comments
Onsite impervious
98
220,015
5.05
Onsite open
54
495,933
11.39
Assume good condition
Onsite wooded
48
640,858
14.71
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
39
0.00
Offsite open
54
4,867
0.11
Assume good condition
Offsite wooded
48
33,968
0.78
Assume good condition
Offsite pond
100
0
0.00
-
Total area =
Composite SCS ON =
% Impervious =
32.04 acres
1,395,680 sq. ft.
58
15.8%

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY
UNW-17060 Sub to Ditch6
Ht. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Segment 2: Concentrated Flow
Length=
100
it
Length=
762
Top Elev=
42.00
ft
Top Elev=
40.00
Bat Elev=
40.00
ft
Bat Elev=
36.28
Height =
2
ft
Height =
4
Slope =
0.0200
ft/ft
Slope =
0.0049
Manning's n=
0.40
wooded, dense underbrush
Paved?=
No
P (2-year/24-hour) =
4.70
inches (Wilmington, NC)
Velocity=
1.13
Segment Time
17.72
minutes
Segment Time
11.27
Segment 3: pipe Flow
Length =
677
ft
Top Elev=
33.91
Bot Elev=
33.00
Height =
0.91
ft
Slope =
0.0013
ft/ft
Manning's n =
0.013
concrete
Flow Area =
1.23
sf (assume 15" RCP)
Wetted Perimeter=
1.96
If (assume 15" RCP)
Channel Velocity=
3.07
ft/sec
Segment Time =
3.67
minutes
Time of Concentration= 32.66 minutes
SCS Lag Time= 19.59 minutes (SCS Lag =0.6-Tc)
Time Increment = 5.68 minutes (=0.29-SCS Lag)
R. STUBBS, El
2/9/2018
ft
ft
ft
ft
ft/ft
ft/sec
minutes

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Ditch? 2/9/2018
1. SCS CURVE NUMBER$
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
0
98
80
77
HSG'A'= 67.2%
H5G'B'= 32.8%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments
_ Impervious
98
-
Open
46
Assume good condition
Wooded
38
Assume good condition
11. PRE -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS CN
Area
Area acres
Comments !
Onsite impervious
98
4,044
0.09
Onsite open
46
20,610
0.47
Assume good condition
Onsite wooded
38
65,131
1.50
Assume good condition
Onsite pond
100
0
0.00
-
OffsiteImpervious
98
4,661
0.11
Offsite open
46
16,067
0.37
Assume good condition
Offsite wooded
38
0
0.00
Assume good condition
Offsite pond
100
0
0.00
-
Total area=
2.54 acres
110,513 sq. h.
Composite SCs CN =
46
% Impervious =
7.9%

UNCW HURST HAMILTON PARKING LOT PRE -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Ditch7 2/9/2018
Ill. TIME OF CONCENTRATION INFORMATION
Time oJconcentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Segment 2: Concentrated Flow
Length=
100
it
Length=
96
Top Elev=
37.25
ft
Top Elev=
36.00
Bot Elev=
36.00
it
Bot Elev=
35.00
Height=
1.25
ft
Height=
1
Slope=
0.0125
11
Slope=
0.0104
Manning's o=
0.40
wooded, dense underbrush
Paved?=
No
P (2-year/24-hour)=
4.70
inches (Wilmington, NC)
Velocity
1.65
Segment Time=
21.38
minutes
Segment Time
0.97
Segment 3: Channel Flow
Segment 4: Channel Flow
Length=
104
ft
Length=
389
Top Elev=
35.00
Top Elev=
34.00
Bot Elev=
34.00
Bat Elev=
33.00
Height=
1
ft
Height=
1
Slope=
0,0096
WIT
Slope=
0.0026
Manning's n=
0.045
nautral channel
Manning's n=
0.045
Flow Area=
6.00
sf(assume 2'w x Th channel(
Flow Area=
50.00
Wetted Perimeter=
8.00
If (assume 2'w x Th channel(
Wetted Perimeter
25.00
Channel Velocity=
2.68
ft/sec
Channel Velocity=
2.66
Segment Time=
0.65
minutes
Segment Time=
2.43
Time of Concentration= 25.43 minutes
SCS Lag Time= 15.26 minutes (SCS Lag =0.6-Tc)
Time Increment= 4.43 minutes(=0.29'SCS Lag)
it
It
it
it
ft/ft
ft/sec
minutes
it
ft/ft
nautral channel
sf )assume 5'w x 10'h channe
If (assume 5'w x 30'h channel
ft/sec
minutes

9 MCADAMS
Scenario: Pre- Development
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppo 2/9/2018

2 MCADAMS
FlexTable: Catchment Table
(UNW17060.ppc)
Current Time: 0.00 min
Notes Label Area SCS CN Time of Concentration
M) (min)
Pre
Sub to Ditch#6
1,395,680
58
32.66
Pre
Sub to Ditch#7
110,513
46
25.43
Pre
Sub to Forebay
837,341
74
23.41
Pre
Sub to MainPool
225,385
57
25.37
Post
Sub to Ditch#1
263,581
68
18.10
Post
Sub to Ditch#2
1,016,238
58
32.56
Post
Sub to Ditch#3
11,492
71
5.00
Post
Sub to Ditch#4
27,400
52
5.00
Post
Sub to Ditch#5
33,897
71
5.00
Post
Sub to Forebay
837,646
74
23.41
Post
Sub to Main Pool
381,257
82
25.37
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

9 MCADAMS
Subsection: Master Network Summary
Catchments Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event Volume (min) (ft3/s)
(years) (ac-ft)
Sub to Forebay
Pre- lyr 24hr
1
2.399
733.50
25.42
Sub to Forebay
Pre- 2yr 24hr
2
3.385
733.50
36.25
Sub to Forebay
Pre- 10yr 24hr
10
6.868
733.50
64.99
Sub to Forebay
Pre- 25yr 24hr
25
9.545
733.50
82.27
Sub to Forebay
Pre- 50yr 24hr
50
12.020
733.50
95.73
Sub to Forebay
Pre- 100yr 24hr
100
14.872
733.50
109.15
Sub to Ditch#6
Pre- lyr 24hr
1
1.607
749.00
9.79
Sub to Ditch#6
Pre- 2yr 24hr
2
2.655
744.50
18.90
Sub to Ditch#6
Pre- 10yr 24hr
10
6.925
740.25
51.51
Sub to Ditch#6
Pre- 25yr 24hr
25
10.551
740.25
74.87
Sub to Ditch#6
Pre- 50yr 24hr
50
14.063
740.25
94.69
Sub to Ditch#6
Pre- 100yr 24hr
100
18.239
740.25
115.61
Sub to MainPool
Pre- lyr 24hr
1
0.242
740.75
1.58
Sub to MainPool
Pre- 2yr 24hr
2
0.405
737.50
3.22
Sub to MainPool
Pre- 10yr 24hr
10
1.078
734.25
9.05
Sub to MainPool
Pre- 25yr 24hr
25
1.654
734.00
13.27
Sub to MainPool
Pre- 50yr 24hr
50
2.214
734.00
16.82
Sub to MainPool
Pre- 100yr 24hr
100
2.862
734.00
20.56
Sub to Ditch#7
Pre- Syr 24hr
1
0.037
759.50
0.11
Sub to Ditch#7
Pre- 2yr 24hr
2
0.082
756.25
0.38
Sub to Ditch#7
Pre- 10yr 24hr
10
0.308
739.00
2.12
.Sub to Ditch#7
Pre- 25yr 24hr
25
0.526
735.75
3.80
Sub to Ditch#7
Pre- 50yr 24hr
50
0.749
735.75
5.34
Sub to Ditch#7
Pre- 100yr 24hr
100
1.026
735.75
7.02
Node Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event Volume (min) (ft3/s)
(years) (ac-ft)
Overall POA
Pre- lyr 24hr
1
0.000
0.00
0.00
Overall POA
Pre- 2yr 24hr
2
0.000
0.00
0.00
Overall PICA
Pre- 10yr 24hr
10
7.524
839.71
21.66
Overall POA
Pre- 25yr 24hr
25
14.500
799.So
32.47
Overall POA
Pre- 50yr 24hr
50
21.210
791.00
38.64
Overall POA
Pre- 100yr 24hr
100
28.969
788.50
40.18
Pond Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event Volume (min) (ft3/s)
(years) (ac-ft)
Maximum
Maximum
Water
Pond Storage
Surface
(ac-ft)
Elevation
(ft)
Pre-Forebay
Pre- Syr 24hr
1
2.399
733.50
25.42
(N/A)
(N/A)
(IN)
Pre-Forebay
Pre- lyr 24hr
1
1.026
748.75
15.52
35.70
1.901
(OUT)
Pre-Forebay
Pre- 2yr 24hr
2
3.385
733.50
36.25
(N/A)
(N/A)
(IN)
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

9 MCADAMS
Subsection: Master Network Summary
Pond Summary
Label
Scenario
Return
Hydrograph
Time to Peak
Peak Flow
Maximum
Maximum
Event
Volume
(min)
(ft3/s)
Water
Pond Storage
(years)
(ac-ft)
Surface
(ac-ft)
Elevation
(ft)
Pre-Forebay
Pre- 2yr 24hr
2
1.299
745.00
23.98
36.30
2.613
(OLro
Pre-Forebay
Pre- 10yr 24hr
10
6.868
733.50
64.99
(N/A)
(N/A)
(IN)
Pre-Forebay
Pre- 10yr 24hr
10
4.424
736.25
36.80
36.66
3.163
(Our)
Pre-Forebay
Pre- 25yr 24hr
25
9.545
733.50
82.27
(N/A)
(N/A)
(IN)
Pre-Forebay
Pre- 25yr 24hr
25
7.080
727.00
32.94
36.87
3.507
(OUn
Pre-Forebay
Pre- 50yr 24hr
50
12.020
733.50
95.73
(N/A)
(N/A)
(IN)
Pre-Forebay
Pre- 50yr 24hr
50
9.535
738.75
39.34
37.02
4.393
(Olf )
Pre-Forebay
Pre- 100yr
100
14.872
733.50
109.15
(N/A)
(N/A)
(IN)
24hr
Pre-Forebay
Pre- 100yr
100
12.311
734.50
43.98
37.06
6.406
(our)
24hr
Pre -Main Pool
Pre- lyr 24hr
1
1.267
748.50
16.95
(N/A)
(N/A)
(IN)
ire-MainPool
Pre- lyr 24hr
1
0.000
0.00
0.00
35.70
4.292
(OUP
Pre -Main Pool
Pre- Syr 24hr
1
-1.052
759.50
-8.53
(N/A)
(N/A)
(Reverse)
Pre -Main Pool
Pre- 2yr 24hr
2
1.704
744.75
26.84
(N/A)
(N/A)
(IN)
Pre-MainPool
Pre- 2yr 24hr
2
0.000
0.00
0.00
36.30
5.281
(OUT)
Pre-MainPool
Pre- 2yr 24hr
2
-1.623
749.75
-12.85
(N/A)
(N/A)
(Reverse)
Pre-MainPool
Pre- 10yr 24hr
10
5.502
736.25
45.83
(N/A)
(N/A)
(IN)
Pre-MainPool
Pre- 10yr 24hr
10
3.130
872.00
10.13
36.64
6.014
(OUn
Pre-MainPool
Pre- 10yr 24hr
10
-1.410
742.50
-22.53
(N/A)
(N/A)
(Reverse)
Pre-MainPool
Pre- 25yr 24hr
25
8.734
734.25
45.78
(N/A)
(N/A)
(IN)
Pre -Main Pool
Pre- 25yr 24hr
25
5.816
768.00
19.29
36.80
6.367
(OUT)
Pre-MainPool
Pre- 25yr 24hr
25
-0.943
730.75
-19.40
(N/A)
(N/A)
(Reverse)
Pre-MainPool
Pre- 50yr 24hr
50
11.749
738.50
55.42
(N/A)
(N/A)
(IN)
Pre-MainPool
Pre- 50yr 24hr
50
8.888
768.00
28.91
36.92
6.638
(OUT)
Pre -Main Pool
Pre- 50yr 24hr
50
-1.021
718.75
-16.20
(N/A)
(N/A)
(Reverse)
Pre -Main Pool
Pre- 100yr
100
15.193
734.50
64.48
(N/A)
(N/A)
;IN)
24hr
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppe 2/9/2018

DUI MCADAMS
Subsection: Master Network Summary
Pond Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event Volume (min) (ft3/S)
(years) (ac-ft)
Pre-MainPool
(OUT)
Pre-MamPool
(Reverse)
Ditch #6
(IN)
Ditch #6
(OUT)
Ditch #6
(IN)
Ditch #6
(OUn
Ditch #6
(IN)
Ditch #6
(OUn
Ditch #6
(IN)
Ditch #6
(OUT)
Ditch #6
(IN)
Ditch #6
(OUT)
Ditch #6
(IN)
Ditch #6
(OUT)
Ditch#7 (IN)
Ditch#7
(Reverse)
Ditch#7
(OUn
Ditch#7 (IN)
Ditch#7
(Reverse)
Ditch#7
(OUT)
Ditch#7 (IN)
Ditch#7
(OUT)
Ditch#7 (IN)
Ditch#7
(OUT)
Ditch#7 (IN)
Ditch#7
(OUT)
Ditch#7 (IN)
Ditch#7
(OUT)
Hamilton -Hurst Pai
UNW17060.ppc
Pre- 100yr
24hr
Pre- 100yr
24hr
Pre- lyr 24hr
Pre- lyr 24hr
Pre- 2yr 24hr
Pre- 2yr 24hr
Pre- 10yr 24hr
Pre- 10yr 24hr
Pre- 25yr 24hr
Pre- 25yr 24hr
Pre- 50yr 24hr
Pre- 50yr 24hr
Pre- 100yr
24hr
Pre- 100yr
24hr
Pre- lyr 24hr
Pre- lyr 24hr
Pre- lyr 24hr
Pre- 2yr 24hr
Pre- 2yr 24hr
Pre- 2yr 24hr
Pre- 10yr 24hr
Pre- 10yr 24hr
Pre- 25yr 24hr
Pre- 25yr 24hr
Pre- 50yr 24hr
Pre- 50yr 24hr
Pre- 100yr
24hr
Pre- 100yr
24hr
ding Lot
100
100
11
1
2
2
10
10
25
25
50
50
100
100
1
1
1
2
2
2
10
10
25
25
5o
50
100
100
12.474
749.75
31.14
-1.230
698.50
-12.94
1.607
749.00
9.79
1.365
758.75
8.94
2.655
744.50
18.90
2.233
757.25
16.44
6.925
740.25
51.51
6.398
747.25
28.39
10.551
740.25
74.87
10.012
735.50
27.70
14.063
740.25
94.69
13.514
729.25
26.19
18.239
740.25
115.61
17.662
721.25
24.06
0.337
735.25
2.80
-0.007
1,270.25
-0.50
0.000
0.00
0.00
0.691
757.50
4.16
0.000
1,257.75
-0.14
0.000
0.00
0.00
8.426
803.25
25.84
7.524
839.75
21.66
15.411
768.00
38.25
14.500
799.50
32.47
22.131
755.00
47.22
21.210
791.00
38.64
29.931
741.50
50.84
28.969
788.50
40.18
Maximum
Water
Surface
Elevation
(ft)
36.97
(N/A)
(N/A)
35.72
(N/A)
36.31
(N/A)
37.01
(N/A)
37.06
(N/A)
37.12
(N/A)
37.18
(N/A)
(N/A)
35.72
(N/A)
(N/A)
36.30
(N/A)
36.63
(N/A)
36.78
(N/A)
36.89
(N/A)
36.93
Maximum
Pond Storage
(ac-ft)
6.742
(N/A)
(N/A)
0.242
(N/A)
0.422
(N/A)
1.328
(N/A)
3.390
(N/A)
5.623
(N/A)
8.256
(N/A)
(N/A)
0.334
(N/A)
(N/A)
0.692
(N/A)
1.038
(N/A)
1.256
(N/A)
1.419
(N/A)
1.466
R. STUBBS, El
2/9/2018

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SHEFT NO. PRE
'J MCADAMS

POST -DEVELOPMENT
HYDROLOGIC CALCULATIONS
UNCW - HURST HAMILTON PARKING LOTS
UN W-17060

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
U N W-17060 Summary of Results 2/9/2018
HYDROLOGY INPUT SUMMARY
Onsite Area [acres]
Offsite
Area [acres]
Total Area
Sub -basin ID
Impervious
Open
Wooded
Pond
Total
Impervious
Open
Wooded
Pond
Total
[acres]
SCS CN
Tc [min]
Main Pool
4.95
1.96
0.39
0.95
8.25
0.22
0.28
0.00
0.00
0.50
8.75
82
25.37
Forebay
8.79
9.49
0.00
0.45
18.73
0.00
0.50
0.00
0.00
0.50
19.23
74
23.41
Ditchl
2.30
3.75
0.00
0.00
6.05
0.00
0.00
0.00
0.00
0.00
6.05
68
18.10
Ditch2
2.92
7.58
11.97
0.00
22.46
0.00
0.09
0.78
0.00
0.86
23.33
58
32.56
Ditch3
0.09
0.14
0.00
0.00
0.24
0.00
0.03
0.00
0.00
0.03
0.26
71
5.00
Ditch4
0.09
0.44
0.00
0.00
0.54
0.01
0.08
0.00
0.00
0.09
0.63
52
5.00
Ditch5
0.33
0.27
0.00
0.00
0.60
0.01
0.17
0.00
0.00
0.18
0.78
71
5.00
Totals =
19.48 23.63 12.36 1.39 56.87
0.24 1.14 0.78 0.00 2.17
59.03

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub t0 M010 Pool 2/9/2018
I. SCS CURVE NUMBER$
Assume:
HSG
Impervious
Open
Wooded
A
98
39
1 30
B
98
61
55
C
98
74
70
D
98
80
77
HSG'A' = 64.2%
HSG'B'= 35.8%
HSG'C' - 0.0%
HSG'D'= 0.0%
' Cover Condition
SCS CN
Comments i
Impervious
98
Open
47
Assume good condition
Zen
39
Assume good condition
11. POST -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS ON
Areas
Area acres
Comments I
Onsite impervious
98
215,633
4.95
Onsite open
47
85,372
1.96
Assume good condition
Onsite wooded
39
17,112
0.39
Assume good condition
Onsite pond
100
41,263
0.95
Offsite im erwous
98
9,554
0.22
Offsite open
47
12,323
0.28
Assume good condition
Offsite wooded
39
0
0.00
Assume good condition
Offsite pond
100
0
0.00
Total area
8.75 acres
381,257 sq. ft.
Composite SCS ON =
82
% Impervious =
59.1%

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UN W-17060 Sub to Main Pool 2/9/2018
Ill. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach lTR.551.
Segment 1: Overland Flow
Segment 2: Concentrated Flow
Length=
100
If
Length=
300
ft
Top Elev=
38.5
it
Tap Elev=
36.50
It
Bot Elev=
36.5
it
Bot Elev=
36
ft
Height=
2
ft
Height=
1
ft
Slope=
0.0200
ft/ft
Slope=
0.0017
ft/ft
Manning's n=
0.40
wooded, dense underbrush
Paved?=
No
P (2-year/24-hour) =
4.70
inches (Wilmington, NC)
Velocity=
0.66
ft/sec
Segment rime=
17.72
minutes
Segment lime=
7.59
minutes
Segment 3: Pipe Flow
Length =
18
It
Top Elev=
36
Bot Elev=
35.75
Height=
0.25
ft
Slope=
0.0139
ft/ft
Mannings n=
0.013
concrete
Flow Area=
0.79
sf(assume 12"RCP)
Wetted Perimeter=
3.14
If (assume 12" RCP)
Channel Velocity=
5.36
ft/sec
Segment rime=
0.06
minutes
Time of Concentration= 25.37 minutes
SCS Lag Time= 15.22 minutes (SCS Lag =0.6-Tc)
Time Increment= 4.41 minutes (=0.29-SC5 Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Forebay 2/9/2018
1. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded I
A
98
39
30
B
1 98
61
55
C
98
74
70
D
98
80
77
H5G'A'= 43.1%
HSG'B'= 56.9%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments i
Impervious
98
Open
52
Assu me good conditi on
Wooded
44
Ass a me good cond iti on
It. POST -DEVELOPMENT
Watershed Breakdown
Contributin Area
SCS CN
Area acres
Comments 1
Onsite impervious
98
8.79
Onsite open
52
9.49
Assume good condition
Onsite wooded
44
DAD
Assume good condition
Onsite pond
100
E1,9
0.45
Offsite impervious
98
0.00
Offsite open
52
0.50
Assume good condition
Offsite wooded
44
0.00
Assume ood condition
Offsite and
100
0.00
Total area=
19.23 acres
837,646 sq. k.
Composite SCS CN=
74
% Impervious =
45.7%

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Foreboy 2/9/2018
Ill. TIME OF CONCENTRATION INFORMATION
Time oJconcentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
Top Elev =
Bot Elev =
Height =
Slope =
Manning's n =
P (2-year/24-hour)=
Segment Time=
Segment 3: Pipe Flow
Length =
Top Elev =
Bot Elev =
Height =
Slope =
Manning's o =
Flow Area =
Wetted Perimeter=
Channel Velocity=
Segment rime =
Segment 2: Concentrated Flow
100
it
Length =
235
it
41
R
Top Elev=
40.5
it
40.5
ft
Bot Elev=
37.9
it
0.5
it
Height=
3
it
0.0050
Wit
Slope=
0.0111
Wit
0.24
dense grass
Paved?=
No
4.70
inches (Wilmington, NC)
Velocity=
1.70
ft/sec
20.50
minutes
Segment Time
2.31
minutes
358
fit
37.9
34
3.9
it
0.0109
Wit
0.013
concrete
1.77
sf (assume 18" RCP)
2.36
If (assume 18" RCP)
9.88
ft/sec
0.60
minutes
Time of Concentration= 23.41 minutes
SCS Lag Time= 14.05 minutes SCS Lag =0.6-Tc)
Time Increment= 4.07 minutes 1=0.29'SCS Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUB85, El
UNW-17060 Sub to Ditchl 2/9/2018
1. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded '
A
98
39
30
8
98
61
55
C
98
74
70
D
98
Bo
77
HSG'A'= 48.2%
HSG'B'= 51.8%
H5G'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments i
Impervious
98
Open
50
Assume good condition
Wooded
43
Assume good condition
II. POST -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS CN
Area
Area acres
Comments
Onsite impervious
98
100,155
2.30
Onsite open
50
163,426
3.75
Assume good condition
Onsite wooded
43
0
0.00
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
0
0.00
Offsite open
50
0
0.00
Assume good condition
Offsite wooded
43
0
0.00
Assume good condition
Offsite pond
100
0
0.00
Total area =
6.05 acres
263,581 sq. R.
Composite SCS CN =
fib
%Impervious=
38.0%

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Ditchl 2/9/2018
III. TIME OF CONCENTRATION INFORMATION
Time of concentrotion is colculoted using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Segmeat2: Conrentroted Flow
Length=
100
8
Length=
513
ft
Top Elev=
42.00
it
Tap Elev=
39.00
ft
sot Elev =
39.00
It
Bot El" =
36.40
ft
Height=
3
it
Height=
3
ft
Slope=
0.0300
ft/ft
Slope=
0.0051
ft/ft
Manning's a=
0.24
dense grass
Paved?=
No
P (2-year/24-hour) =
4.70
inches (Wilmington, NC)
Velocity=
1.15
ft/sec
Segment Time
10.01
minutes
Segment Time=
7.44
minutes
Segment 3: pipe Flow
Length =
164
it
Top Elev=
34.37
Bot Elev=
34.04
Height=
0.33
ft
Slope=
0.0020
ft/ft
Manning's n=
0.013
concrete
Flow Area=
1.77
sf(assume 18"RCP)
Wetted Perimeter=
2.36
If (assume 18"PCP)
Channel Velocity=
4.24
ft/sec
Segment Time=
0.64
minutes
Time of Concentration= 18.10 minutes
SCS Lag Time= 10.86 minutes (SCS Lag =0.6-Tel
Time Increment= 3.15 minutes 1=0.29-SCS Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW- 7060 Sub to Ditch2 2/9/2018
Assume:
HSG
Impervious
Open
Wooded I
A
98
39
30
B
1 98
61
55
C
98
74
70
D
98
80
77
HSG'A' = 21.7%
HSG'B'= 78.3%
HSG'C'= 0.0%
H5G'D'= 0.0%
Cover Condition
SCS CN
Comments
Impervious
98
Open
56
Assumegood con dition
Wooded
50
Assume goad condition
II. POST -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS CN
Area (sq
Area acres
Comments I
Onsite impervious
98
127,154
2.92
Onsite open
56
330,098
7.58
Assume good condition
Onsite wooded
50
521,308
11.97
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
0
0.00
Offsite open
56
3,710
0.09
Assume good condition
Offsite wooded
50
33,968
0.78
Assume good condition
Offsite pond
100
0
0.00
-
Total area=
23.33 acres
1,016,238 sq. R.
Composite SCS ON =
58
% Impervious =
12.5%

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to Ditch2 2/9/2018
III. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach ITR-55).
Segment 1: Overland Flow
Segment 2: Concentrated Flow
Length=
100
it
Length=
762
it
Top Elev=
42.00
it
Top Elev=
40.00
it
But Elev=
40.00
it
Bot Elev=
36.28
it
Height=
2
it
Height=
4
ft
Slope=
0.0200
ft/ft
Slope=
0.0049
ft/ft
Manning's n=
0.40
dense grass
Paved ?=
No
P (2-year/24-hour) =
4.70
inches (Wilmington, NC)
Velocity=
1.13
ft/sec
Segment Time
17.72
minutes
Segment Three =
11.27
minutes
Segment 3: Pipe Flow
Length=
665
It
Top Elev=
33.91
Bot Elev=
33.00
Height=
0.91
It
Slope=
0.0014
ft/ft
Manning's n=
0.013
concrete
Flow Area =
1.23
sf (assume 15" RCP)
Wetted Perimeter =
1.96
If (assume 15" RCP)
Channel Velocity=
3.10
fit/sec
Segment Time=
3.58
minutes
Time of Concentration= 32.56 minutes
SCS Lag Time= 19.54 minutes(SCS Lag =0.6-Tc)
Time Increment= 5.67 minutes )=0.29-SCS Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, EI
UNW-17060 Sub to Oitch3 2/9/2018
I. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
1 74
70
D
98
1 so
77
HSG'A'= 21.0%
HSG'B'= 79.0%
HSG'C' = 0.0%
H5G'D'= 0.0%
Cover Condition
SCS ON
Comments
Impervious
98
Open
56
Assume good condition
Wooded
50
Assume good condition
11. POST -DEVELOPMENT
Watershed Breakdown
Contributing AreaM56
Areas
Area acres
Comments
Onsite impervious4,064
0.09
-
Onsite open6,233
0.14
Assume good condition
Onsitewooded0
0.00
Assume good condition
Onsite anda
0.00
Offsiteim ervious39
0.00
Offsiteo en1,156
0.03
Assume ood condition
Offsite wooded0
0.00
Assume ood condition
Offsite and0
0.00
Total area=
0.26 acres
11,492 sq. ft.
Composite SCS ON =
71
% Impervious =
35.7%
Time o)concentration is calculated using the SCS Segmental Approach (TR-55).
Time of Concentration= 5.00 minutes
SCS Lag Time= 3.00 minutes)SCS Lag =0.6•Tc)
Time Increment= 0.87 minutes )=0.29-SCS Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub t0 Ditch4 2/9/2018
1. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
H5G'A'= 79.9%
HSG'B'= 20.1%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments I
Impervious
98
Open
43
Assume good condition
Wooded
35
Assume good condition
IL POST -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS ON
Area 5
Area acres
Comments
Onsite impervious
98
4,010
0.09
Onsite open
43
19,383
0.44
Assume good condition
Onsite wooded
35
0
0.00
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
543
0.01
Offsite open
43
3,464
0.08
Assume good condition
Offsite wooded
35
0
0.00
Assume good condition
Offsite pond
100
0
0.00
-
Total area=
0.63 acres
27,400 sq. ft.
Composite SCS CN=
52
%Impervious=
16.6%
III._ TIME OF CONCENTRATION INFORMATION
Time o com entrotion is calculated using the SCS Segmental Approach (TR-55).
Time of Concentration= 5.00 minutes
SCS Lag Time= 3.00 minutes (SCS Lag =0.6-Tc)
Time Increment= 0.87 minutes (=0.29-SCS Lag)

UNCW HURST HAMILTON PARKING LOT POST -DEVELOPMENT HYDROLOGY R. STUBBS, El
UNW-17060 Sub to DitchS 2/9/2018
I. SCS CURVE NUMBERS
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
1 98
61
55
C
98
74
70
D
98
80
77
H5G'A'= 47.0%
HSG'B'= 53.0%
HSG'C'= 0.0%
HSG'D'= 0.0%
Cover Condition
SCS CN
Comments i
_ Impervious
98
Open
51
Assu me good conditi on
wooded
43
Assume good condition
If. POST -DEVELOPMENT
Watershed Breakdown
Contributing Area
SCS ON
Areas
Area acres
Comments
Onsite impervious
98
14,435
0.33
Onsite open
51
11,823
0.27
Assume good condition
Onsite wooded
43
0
0.00
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
440
0.01
Offsite open
51
7,199
0.17
Assume good condition
Offsite wooded
43
0
0.00
Assume good condition
Offsite pond
100
0
0.00
-
Total area=
0.78 acres
33,897 sq. ft.
Composite SCS CN =
71
% Impervious =
43.9%
III. TIME OF CONCENTRATION INFORMATION
Time o)concentmtion is calculated using the SCS Segmental Approach (TR-55).
Time of Concentration= 5.00 minutes
SCS Lag Time= 3.00 minutes (SCS Lag =0.6-Tc)
Time Increment= 0.87 minutesI=0.29-SCS La

9 MCADAMS
Scenario: Post- Development
Hamilton -Hurst Parking Lot R, STUBBS, El
UN W 17060.ppc 2/9/2018

9 MCADAMS
FlexTable: Catchment Table
(UNW17060.ppc)
Current Time: 0.00 min
Notes Label Area SCS CN Time of Concentration
W) (min)
Pre
Sub to Ditch#6
1,395,680
58
32.66
Pre
Sub to Ditch#7
110,513
46
25.43
Pre
Sub to Forebay
837,341
74
23.41
Pre
Sub to MainPool
225,385
57
25.37
Post
Sub to Ditch#1
263,581
68
18.10
Post
Sub to Ditch#2
1,016,238
58
32.56
Post
Sub to Ditch#3
11,492
71
5.00
Post
Sub to Ditch#4
27,400
52
5.00
Post
Sub to Ditch#5
33,897
71
5.00
Post
Sub to Forebay
837,646
74
23.41
Post
Sub to Main Pool
381,257
82
25.37
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc M12018

!UI MCADAMS
Subsection: Master Network Summary
Catchments Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event Volume (min) (ft3/s)
(vears) (ac-ft)
Sub to Forebay
Post- lyr 24hr
1
2.400
733.50
25.43
Sub to Forebay
Post- 2yr 24hr
2
3.386
733.50
36.26
Sub to Forebay
Post- 10yr 24hr
10
6.871
733.50
65.02
Sub to Forebay
Post- 25yr 24hr
25
9.548
733.50
82.30
Sub to Forebay
Post- 50yr 24hr
50
12.024
733.50
95.76
Sub to Forebay
Post- 100yr 24hr
100
14.877
733.50
109.19
Sub to Main Pool
Post- lyr 24hr
1
1.522
734.00
15.98
Sub to Main Pool
Post- 2yr 24hr
2
2.038
734.00
21.24
Sub to Main Pool
Post- 10yr 24hr
10
3.776
734.00
33.99
Sub to Main Pool
Post- 25yr 24hr
25
5.067
734.00
41.28
Sub to Main Pool
Post- 50yr 24hr
50
6.243
734.00
46.87
Sub to Main Pool
Post- 100yr 24hr
100
7.585
734.00
52.41
Sub to Ditch#1
Post- lyr 24hr
1
0.566
731.25
6.49
Sub to Ditch#1
Post- 2yr 24hr
2
0.837
731.25
9.90
Sub to Ditch#1
Post- 10yr 24hr
10
1.837
729.00
19.50
Sub to Ditch#1
Post- 25yr 24hr
25
2.631
729.00
25.62
Sub to Ditch#1
Post- 50yr 24hr
50
3.376
729.00
30.42
Sub to Ditch#1
Post- 100yr 24hr
100
4.242
729.00
35.28
Sub to Ditch#2
Post- lyr 24hr
1
1.170
746.75
7.15
Sub to Ditch#2
Post- 2yr 24hr
2
1.933
742.50
13.75
Sub to Ditch#2
Post- 10yr 24hr
10
5.043
742.25
37.44
;ub to Ditch#2
Post- 25yr 24hr
25
7.683
738.25
54.23
Sub to Ditch#2
Post- 50yr 24hr
50
10.240
738.25
68.76
Sub to Ditch#2
Post- 100yr 24hr
100
13.281
738.00
84.13
Sub to Ditch#3
Post- lyr 24hr
1
0.029
721.50
0.56
Sub to Ditch#3
Post- 2yr 24hr
2
0.042
721.50
0.82
Sub to Ditch#3
Post- 10yr 24hr
10
0.088
721.25
1.50
Sub to Ditch#3
Post- 25yr 24hr
25
0.123
721.25
1.91
Sub to Ditch#3
Post- 50yr 24hr
50
0.157
721.25
2.21
Sub to Ditch#3
Post- 100yr 24hr
100
0.195
721.25
2.53
Sub to Ditch#4
Post- lyr 24hr
1
0.019
726.00
0.17
Sub to Ditch#4
Post- 2yr 24hr
2
0.035
722.75
0.44
Sub to Ditch#4
Post- 10yr 24hr
10
0.106
721.50
1.63
Sub to Ditch#4
Post- 25yr 24hr
25
0.170
721.25
2.50
Sub to Ditch#4
Post- 50yr 24hr
50
0.233
721.25
3.21
Sub to Ditch#4
Post- 100yr 24hr
100
0.309
721.25
4.01
Sub to Ditch#5
Post- lyr 24hr
1
0.085
721.50
1.66
Sub to Ditch#5
Post- 2yr 24hr
2
0.123
721.50
2.43
Sub to Ditch#5
Post- 10yr 24hr
10
0.258
721.25
4.43
Sub to Ditch#5
Post- 25yr 24hr
25
0.364
721.25
5.65
Sub to Ditch#5
Post- 50yr 24hr
So
0.462
721.25
6.52
Sub to Ditch#5
Post- 100yr 24hr
100
0.576
721.25
7.48
Node Summary
Label Scenario
Jverall PDA Post- lyr 24hr
Overall PDA Post- 2yr 24hr
Return Hydrograph
Event Volume
;years) (ac-ft)
1 1 0.000
2 1.166
Time to Peak Peak Flow
(min) (ft3/s)
u.UU U.UU
1,402.00 2.39
Hamilton -Hurst Parking Lot R. STUBBS, EI
UNW17060.ppc 2/9/2018

9 MCADAMS
Subsection: Master Network Summary
Node Summary
Label
Scenario
Return
Hydrograph
Event
Volume
(years)
(ac-ft)
Overall POA
Post- 10yr 24hr
10
10.647
Overall POA
Post- 25yr 24hr
25
18.156
Overall POA
Post- 50yr 24hr
50
23.054
Overall POA
Post- 100yr 24hr
100
26.952
Pond Summary
Label Scenario Return Hydrograph
Event Volume
(years) (ac-ft)
Time to Peak
Peak Flow
(min)
(ft3/s)
798.50
25
779.2
28.3.86
19
751.00
28.92
751.50
29.67
Time to Peak Peak Flow
(min) (ft3/s)
Maximum
Maximum
Water
Pond Storage
Surface
(ac-ft)
Elevation
(ft)
Post-Forebay
Post- lyr 24hr
1
2.400
733.50
25.43
(N/A)
(N/A)
(IN)
Post-Forebay
Post- lyr 24hr
1
0.482
742.00
13.77
36.09
2.485
(OUT)
Post-Forebay
Post- lyr 24hr
1
-0.038
784.75
-0.59
(N/A)
(N/A)
(Reverse)
Post-Forebay
Post- 2yr 24hr
2
3.386
733.50
36.26
(N/A)
(N/A)
(IN)
Post-Forebay
Post- 2yr 24hr
2
0.974
738.75
19.33
36.53
3.131
(our)
post-Forebay
Post- 2yr 24hr
2
-0.189
774.00
-2.68
(N/A)
(N/A)
(Reverse)
Post-Forebay
Post- 10yr
10
6.871
733.50
65.02
(N/A)
(N/A)
(IN)
24hr
Post-Forebay
Post- 10yr
10
4.227
726.50
19.98
36.92
3.752
(OUn
24hr
Post-Forebay
Post- 10yr
10
-0.006
447.00
-0.04
(N/A)
(N/A)
(Reverse)
24hr
Post-Forebay
Post-25yr
25
9,548
733.50
82.30
(N/A)
(N/A)
(IN)
24hr
Post-Forebay
Post- 25yr
25
6.860
728.75
18.87
37.04
5.411
(Our)
24hr
Post-Forebay
Post- 25yr
25
-0.005
382.00
-0.04
(N/A)
(N/A)
(Reverse)
24hr
Post-Forebay
Post-50yr
50
12.024
733.50
95.76
(N/A)
(N/A)
(IN)
24hr
Post-Forebay
Post- 50yr
So
9.188
734.75
24.45
37.07
6.991
(OUT)
24hr
Post-Forebay
Post- 50yr
So
-0.006
320.75
-0.04
(N/A)
(N/A)
(Reverse)
24hr
Post-Forebay
Post-100yr
100
14.877
733.50
109.19
(N/A)
(N/A)
(IN)
24hr
Post-Forebay
Post- 100yr
100
11.962
725.25
20.87
37.11
8.698
(OUT)
24hr
Post-Forebay
Post- 100yr
100
-0.007
704.00
-0.27
(N/A)
(N/A)
(Reverse)
24hr
Post -Main
Post- 1yr 24hr
1
1.967
739.75
27.56
(N/A)
(N/A)
Pool (IN)
lost -Main
Post- lyr 24hr
1
0.000
0.00
0.00
36.09
5.381
Pool (OUT)
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

9 MCADAMS
Subsection: Master Network Summary
Pond Summary
Label Scenario
Post -Main Post- lyr 24hr
Pool
(Reverse)
Post -Main Post- 2yr 24hr
Pool (IN)
Post -Main Post- 2yr 24hr
Pool (OUT)
Post -Main Post- 2yr 24hr
Pool
(Reverse)
Post -Main Post- 10yr
Pool (IN) 24hr
Post -Main Post- 10yr
Pool (OUT) 24hr.
Post -Main Post- 10yr
Pool 24hr
(Reverse)
Post -Main Post- 25yr
Pool (IN) 24hr
Post -Main Post- 25yr
Pool (OUT) 24hr
Post -Main Post- 25yr
Pool 24hr
(Reverse)
Post -Main Post- 50yr
Pool (IN) 24hr
Post -Main Post- 50yr
Pool (OUT) 24hr
Post -Main Post- 50yr
Pool 24hr
(Reverse)
Post -Main Post- 100yr
Pool (IN) 24hr
Post -Main Post- 100yr
Pool (OUT) 24hr
Post -Main Post- 100yr
Pool 24hr
(Reverse)
Ditchl (IN) Post- lyr 24hr
Ditchl (OUT) Post- lyr 24hr
Ditchl (IN) Post- 2yr 24hr
Ditchl (OUT) Post- 2yr 24hr
Ditchl (IN) Post- 10yr
24hr
Ditchl (OUT) Post- 10yr
24hr
Ditchl Post- 10yr
(Reverse) 24hr
Ditchl (IN) Post-25yr
24hr
Return Hydrograph Time to Peak Peak Flow Maximum Maximum
Event Volume (min) (ft3/s) Water Pond Storage
(years) (ac-ft) Surface (ac-ft)
Elevation
(ft)
1 I -1.192 I 752.25 I -9.32 I (N/A) I (N/A)
2
2
2
10
10
10
25
25
25
50
50
50
100
100
100
1
1
2
2
10
10
10
25
2.823
0.638
1.543
7.997
5.110
-0.876
11.921
9.030
-0.905
15.425
12.653
-1.143
19.540
16.860
-1.293
0.566
0.513
0.637
0.753
1.837
1.819
-0.069
2.631
737.25
1,407.25
743.50
733.75
795.75
735.50
728.75
765.50
723.75
734.75
755.25
720.50
725.25
735.75
708.50
731.25
735.50
731.25
733.75
729.00
Pp411Ki
779.50
729.00
39.46
1.36
-13.78
51.71
15.00
-20.02
56.07
26.35
-22.72
70.95
32.88
-20.21
61.69
35.97
-13.77
6.49
5.73
9.90
8.77
19.50
10.74
-1.14
25.62
(N/A)
36.53
(N/A)
(N/A)
36.88
(N/A)
(N/A)
37.00
(N/A)
(N/A)
37.02
(N/A)
(N/A)
37.04
(N/A)
(N/A)
36.11
(N/A)
36.55
(N/A)
37.10
(N/A)
(N/A)
(N/A)
5.943
(N/A)
(N/A)
6.403
(N/A)
(N/A)
6.602
(N/A)
(N/A)
7.426
(N/A)
(N/A)
8.496
(N/A)
(N/A)
0.053
(N/A)
0.084
(N/A)
0.950
(N/A)
(N/A)
Hamilton -Hurst Parking Lot R. STUBBS, El
UN W 17060.ppc 2/9/2018

9 MCADAMS
Subsection: Master Network Summary
Pond Summary
Label
Scenario
Return
Hydrograph
Time to Peak
Peak Flow
Maximum
Maximum
Event
Volume
(min)
(ft3/5)
Water
Pond Storage
(years)
(ac-ft)
Surface
(ac-ft)
Elevation
(ft)
Ditchl (OU-0
Post- 25yr
25
2.976
723.50
9.35
37.22
1.963
24hr
Ditchl
Post- 25yr
25
-0.438
781.25
-4.23
(N/A)
(N/A)
(Reverse)
24hr
Ditchl (IN)
Post- 50yr
50
3.376
729.00
30.42
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 50yr
50
3.054
717.25
6.80
37.25
2.173
24hr
Ditchl
Post- 50yr
50
-0.330
755.50
-5.12
(N/A)
(N/A)
(Reverse)
24hr
Ditchl (IN)
Post- 100yr
100
4.242
729.00
35.28
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 100yr
100
2.235
704.50
5.88
37.25
2.173
24hr
Ditchl
Post- 100yr
100
-0.172
743.75
-4.86
(N/A)
(N/A)
(Reverse)
24hr
Ditchl (IN)
Post- lyr 24hr
1
1.683
739.50
11.97
(N/A)
(N/A)
Ditchl (OUT)
Post- lyr 24hr
1
1.464
751.75
9.98
36.11
0.219
Ditchl (IN)
Post- 2yr 24hr
2
2.686
735.00
20.18
(N/A)
(N/A)
Ditchl (OUP
Post- 2yr 24hr
2
2.389
750.00
17.03
36.55
0.297
Ditchl (IN)
Post- 10yr
10
6.792
742.25
37.89
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 10yr
10
6.486
733.50
23.54
37.11
1.294
24hr
Ditchl (IN)
Post- 25yr
25
10.222
738.00
54.20
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 25yr
25
9.904
726.25
21.00
37.24
2.466
24hr
Ditchl (IN)
Post- 50yr
50
12.965
738.00
67.41
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 50yr
50
11.245
719.25
18.27
37.25
2.521
24hr
Ditchl (IN)
Post- 100yr
100
15.344
738.00
81.01
(N/A)
(N/A)
24hr
Ditchl (OUT)
Post- 100yr
100
10.871
707.00
16.74
37.25
2.521
24hr
Ditch3 (IN)
Post- lyr 24hr
1
1.493
751.25
10.12
(N/A)
(N/A)
Ditch3 (OUT)
Post- lyr 24hr
1
1.473
751.75
10.13
36.10
0.020
Ditch3 (IN)
Post- 2yr 24hr
2
2.431
750.00
17.23
(N/A)
(N/A)
Ditch3 (OUT)
Post- 2yr 24hr
2
2.402
749.50
17.14
36.53
0.029
Ditch3 (IN)
Post- 10yr
10
6.573
733.50
23.94
(N/A)
(N/A)
24hr
Ditch3 (OUT)
Post- 10yr
10
6.543
733.75
22.89
37.00
0.041
24hr
Ditch3 (IN)
Post- 25yr
25
10.027
726.25
22.22
(N/A)
(N/A)
24hr
Ditch3 (Otfr)
Post- 25yr
25
9.996
726.50
21.17
37.09
0.402
24hr
Ditch3 (IN)
Post- 50yr
50
11.402
719.25
20.21
(N/A)
(N/A)
24hr
Hamilton -Hurst Parking
Lot
UN W 17O6O.ppc
R. STUBBS, El
2/9/2018

1111
al McADAMS
Subsection: Master Network Summary
Pond Summary
Label Scenario Return Hydrograph Time to Peak Peak Flow
Event volume (min) (ft3/s)
(years) (ac-ft)
Ditch3 (OUT)
Post- 50yr
50
11.365
719.50
24hr
Ditch3 (IN)
Post- 100yr
100
11.067
707.00
24hr
Ditch3 (OUT)
Post- 100yr
100
11.026
707.25
24hr
Ditch4 (IN)
Post- lyr 24hr
1
0.286
739.25
Ditch4
Post- lyr 24hr
1
-0.003
955.25
(Reverse)
Ditch4 (OUT)
Post- lyr 24hr
1
0.163
738.50
Ditch4
Post- lyr 24hr
1
0.000
725.50
(Reverse)
Ditch4 (IN)
Post- 2yr 24hr
2
1.533
749.00
Ditch4
Post- 2yr 24hr
2
-0.001
773.75
(Reverse)
Ditch4 (OUT)
Post- 2yr 24hr
2
1.367
750.50
Ditch4
Post- 2yr 24hr
2
-0.001
773.75
(Reverse)
Ditch4 (IN)
Past- 10yr
10
10.883
799.00
24hr
Ditch4 (OUT)
Post- 10yr
10
10.719
795.00
24hr
Ditch4
Post- 10yr
10
-0.005
722.00
(Reverse)
24hr
Ditch4 (IN)
Post- 25yr
25
18.295
784.50
24hr
Ditch4
Post- 25yr
25
-0.004
723.75
(Reverse)
24hr
Ditch4 (OUT)
Post- 25yr
25
18.131
787.50
24hr
Ditch4
Past- 25yr
25
-0.012
723.75
(Reverse)
24hr
Ditch4 (IN)
Post- 50yr
50
23.110
755.25
24hr
Ditch4
Post- 50yr
50
-0.002
629.50
(Reverse)
24hr
Ditch4 (OUT)
Post- 50yr
50
22.931
861.00
24hr
Ditch4
Post- 50yr
50
-0.005
720.50
(Reverse)
24hr
Ditch4 (IN)
Post- 100yr
100
26.904
735.75
24hr
Ditch4
Post- 100yr
100
-0.001
554.25
(Reverse)
24hr
Ditch4 (OUT)
Post- 100yr
100
26.719
911.00
24hr
Ditch4
Post- 100yr
100
-0.004
558.00
(Reverse)
24hr
Ditch #5
Post- lyr 24hr
1
0.248
738.50
(IN)
18.88
17.38
16.65
2.70
-0.24
2.13
-0.03
4.31
-0.51
2.86
-0.33
24.73
23.76
-0.88
34.42
-0.79
28.11
-2.21
40.96
-0.07
28.65
-1.41
42.82
-0.06
28.96
-0.10
2.53
Maximum
Water
Surface
Elevation
(ft)
37.12
(N/A)
37.14
(N/A)
(N/A)
36.09
(N/A)
(N/A)
(N/A)
36.53
(N/A)
(N/A)
36.86
(N/A)
(N/A)
(N/A)
36.98
(N/A)
(N/A)
(N/A)
37.00
(N/A)
(N/A)
(N/A)
37.02
(N/A)
(N/A)
Maximum
Pond Storage
(ac-ft)
0.528
(N/A)
0.609
(N/A)
(N/A)
0.126
(N/A)
(N/A)
(N/A)
0.166
(N/A)
(N/A)
0.202
(N/A)
(N/A)
(N/A)
0.215
(N/A)
(N/A)
(N/A)
0.218
(N/A)
(N/A)
(N/A)
0.302
(N/A)
(N/A)
Hamilton -Hurst Parking Lot R. STUBBS, El
UNW17060.ppc 2/9/2018

!J'I MCADAMS
Subsection: Master Network Summary
Pond Summary
Label
Scenario
Return
Hydrograph
Time to Peak
Peak Flow
Maximum
Maximum
Event
Volume
(min)
(ft3/s)
Water
Pond Storage
(years)
(ac-ft)
Surface
(ac-ft)
Elevation
(ft)
Ditch #5
Post- lyr 24hr
1
0.000
0.50
0.00
(N/A)
(N/A)
(Reverse)
Ditch #5
Post- lyr 24hr
1
0.000
0.00
0.00
36.09
0.248
(OU17
Ditch #5
Post- 2yr 24hr
2
1.489
750.50
3.45
(N/A)
(N/A)
(IN)
Ditch #5
Post- 2yr 24hr
2
0.000
773.75
-0.13
(N/A)
(N/A)
(Reverse)
Ditch #5
Post- 2yr 24hr
2
1.166
1,402.00
2.39
36.51
0.322
(OU77
Ditch #5
Post- 10yr
10
10.972
795.00
23.95
(N/A)
(N/A)
(IN)
24hr
Ditch #5
Post- 10yr
10
0.000
0.50
0.00
(N/A)
(N/A)
(Reverse)
24hr
Ditch #5
Post- 10yr
10
10.647
798.50
23.86
36.65
0.347
(OUT)
24hr
Ditch #5
Post-25yr
25
18.483
779.00
28.69
(N/A)
(N/A)
(IN)
24hr
Ditch #5
Post- 25yr
25
0.000
0.50
0.00
(N/A)
(N/A)
(Reverse)
24hr
Ditch #5
Post- 25yr
25
18.156
779.25
28.19
36.71
0.356
(OUT)
24hr
Ditch #5
Post- 50yr
50
23.388
753.75
29.72
(N/A)
(N/A)
(IN)
24hr
Ditch #5
Post- 50yr
50
0.000
0.50
0.00
(N/A)
(N/A)
(Reverse)
24hr
Ditch #5
Post- 50yr
50
23.054
751.00
28.92
36.72
0.359
(OUT)
24hr
Ditch #5
Post- 100yr
100
27.291
727.50
31.10
(N/A)
(N/A)
(IN)
24hr
Ditch #5
Post- 100yr
100
0.000
0.50
0.00
(N/A)
(N/A)
(Reverse)
24hr
Ditch #5
Post- 100yr
100
26.952
751.50
29.67
36.74
0.361
(OUT)
24hr
Hamilton -Hurst Parking Lot R. STUBBS, El
UN W 17060.ppc 2/9/2018

F
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tk
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At
r
i J /
f J \ \\ SUB —BASIN TO FOREBAY c / - Lf ass L
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\ ~ tL \ I S \ j: J / // / i p ^ ' \ C / UNCW PROPERTY LINE
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40
UNCW PROPERTY LINE ✓ �1►/��/i I ��
1 - � ' '� ♦ `� � / % 1 � � / � —, "'> � \ _ �, �
-: T_ y\\v�,��-`; � \ _.\ „♦♦ \ j �� I J \ I I I \ \� \\�,=_ 7`4►.=/ I A \ �-� � bR POA #3 �
\ \ \ \ \ \ \�•. L — J SUB —BASIN TO DITCH 3
\\�♦ \ l \\1 \L / POST —MAIN POOL \ ` AREA = 0.26 AC
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3
gr
♦ I / �:
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\ \ v. \ / 1\ / / s�.o G7 # SUB —BASIN TO DITCH #4
///, /.�.^f.� I/ TCH4 AREA = 0.63 AC
`8 vw ( • `- �,/��
V
iJ �l�
/ - .,�t °' , /�4'' ��a >`\� ."<, SUB —BASIN TO DITCH #5
AREA = 0.78 AC
OVERALL POINT OF ANALYSIS (r
\J
2 3 I 4
M
7
FINAL DRAWING - NOT RELEASED FOR CONSTRUCTION
Al
Fm ■
cI
17 ■
EI
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1� 1
PRmcr ND. UNW-17060
MUNAKE:UNW17060-POST
CHECK DY: DAP
DRAWN BY: RAS
SCAB' 1" = 100°
DAM 1-10-18
SHM NO.
POST
'J McAnaMs

STORMWATER CONTROL MEASURE
DESIGN CALCULATIONS
UNCW - HURST HAMILTON PARKING LOTS
UNW-17060

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UNW-17060 SSFxn Above NP
R. STUBBS, El
2/9/2018
STAGE-STOBAGE FUNCTION COMBINEO7-ABOVE NORMAL POOL ^,
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Stage
Contour Stage Area Area Volume Volume w/S-S Fxn
iRrh7i�Flcl•]
3b.UU
2.70
111075
93886
93886
213279
2.63
36.50
3.20
127233
119154
59577
272856
3.21
37.00
3.70
129342
128288
64144
337000
3.81
400000
Storage vs. Stage
350000
300000
y = 64810X1.2116
R' = 0.9969
V
250000
200000
150000
w
100000
50000
0
0.00
1.00 2.00 3.00 4.00
Stage (feet(
Ks = 64810
b = 1.2316
STAGE -STORAGE FUNCTION - MAIN POOL& PROPOSWFOREBAYS-,ABOVE NORMAL POOL"
Average .Incremental Accumulated Estimated
Contour Contour Contour Contour Stage
I Contour Stage Area Area Volume Volume w/ S-S Fxn
34.30 1.00 48593 44928 44928 44928 0.74
1.70 51158
3b.5U 3.20
56813
55834
27917
160764
2.09
37.00 3.70
58922
57868
28934
189697
2.39
STAGE -STORAGE FUNCTION -EXISTING FOREBAY (Current,ConCition ) -;ABOVE
NORMAL.P,OOL
;:weyY;,; •.';
1
Average
Incremental
Accumulated
Estimated
Contour
Contour
Contour
Contour
Stage
Contour Stage
Area
Area
Volume
Volume
w/5-S Fxn
PIKIPW
3S.00
1.70
25538
25042
17529
39552
0.67
36.00
2.70
56221
40880
40880
80432
1.19
36.50
3.20
70420
63321
31660
112092
1.56
37.00
3.70
70420
70420
35210
147302
1.9S

UNCW HURSTHAM IJON PARKING LOT STORMWATER CONTROL MEASURE
UNW-17060 SSFxn Main Pool
R. STUBBS, El
2/9/2018
STAGE-STORAGE'FUNCTION NIAIN*POOL
Contour
(feet)
Stage
(feet)
Contour
Area
(SF)
Average
Contour
Area
(SF)
Incremental
Contour
Volume
(CF)
Accumulated
Contour
Volume
(CF)
Estimated
Stage
w/S-S Fxn
(feet)
26.00
26.50
-0.50
0.00
20,964
21,595
Sediment Storage
28.00
1.50
23,633
22614
33921
33921
1.52
29.00
2.50
25,014
24324
24324
58245
2.48
30.00
3.50
26,414
2S714
25714
83959
3.46
31.00
4.50
27,838
27126
27126
113085
4.46
32.00
5.50
29,281
28560
28560
139644
5.49
33.00
6.50
30,782
30032
30032
169676
6.55
area and volume used for avg. depth calculation
Storage vs. Stage
200000
180000
-
Y = 21394X11019
160000
R2 = 0.9997
140000
U 120000 -
100000
N
o e0000
N
60000
40000
20000
0
0.00 2.00 4.00 6.00 &00
Stage (feet)
Ks = 21394
h = 1.1019

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UNW-17060 SSFxn Existing Foreboy - Current Condition
R. STUBBS, El
2/9/2018
STAGE -STORAGE FUNCTION FOREBAY
Contour Contour
Contour Contour
Stage
Contour
Stage
Area Area
Volume Volume
w/5-S Fxn
(feet)
(feet)
(SF) (SF)
(CF) (CF)
(feet)
29.00
-1.25
9,132
Sediment Storage
30.25
0.00
11A72
32.00 3.00 16,021 14812 14812 24363 3.17
33.00 4.00 18,557 17289 17289 41652 3.92
33.30 4.30 19,500 19029 5709 47360 4.13
Storage vs. Stage
60000 -
50000
y = 1343.5x25132
R2 = 0.9771
u 40000
U
W 30000
N
O
�
w 20000 -
10000
0
0.00 1.00 2.00 3.00 4.00 5.00
Stage (feet)
KS = 1343.5
b = 2.5132

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UN W-17060 SSFxn Proposed Foreboy p1
R. STUBBS, El
2/9/2018
STAGE -STORAGE FUNCTION FOREBAY
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Stage
Contour Stage Area Area Volume 'Volume w/ S-S Fxn
(feet)
(feet)
(SF)
(SF)
(CF) (CF)
(feet)
27.50
-0.50
1,758
Sediment Storage
28.00
0.00
2,210
29.00
1.50
3,160
2685
2685 2685
1.50
30.00
2.50
4,181
3671
3671 6356
2.51
31.00
3.50
5,264
4723
4723
11078
3.48
32.00
4.50
6,401
5833
5833
16911
4.48
33.00
5.50
7,701
7051
7051
23962
5.51
33.30
5.80
8,081
7891
2367
26329
5.83
30000
25000 -
Storage vs. Stage
y = 1353.5x' �2
R' = 0.9999
u. 20000
U
15000
N
O
w 10000 -
-
5000
0
2.00 4.00 6.00 8.00
0.00
Stage (feet)
Ks = 1353.5
b = 1.6942

UNCW HURST HAMILTON PARKING LOT
STORMWATER CONTROL MEASURE
R. STUBBS, El
UNW-17060
SSFxn Proposed Forebay R2
2/9/2018
STAGE -STORAGE FUNCTION-FOREBAY
-
Estimated
Average Incremental Accumulated
Contour
Contour Contour Contour
Stage
Contour Stage
Area
Area Volume Volume
w/5-S Fxn
(feet) (feet)
(SF)
(SF) (CF) (CF)
(feet)
29.00 -0.50
192
Sediment Storage
29.50 0.00
271
30.00 1.00
383
327 164 164
0.99
31.00 2.00
631
507 507 671
2.05
32.00 3.00 851 741 741 1412 3.02
33.00 4.00
33.30 4.30
Storage vs. Stage
3000
2500
y = 168.22xI 9239
W = 0.9992
2000
c
U
1500
N
0
w 1000 -
500
0
0.00 1.00 2.00 3.00 4.00 5.00
Stage (feet)
Ks = 168.2
b = 1.9239

Uecw HURS7 HAMILTON PARKING to STORM W ATER CONTROL MEASURE R. STUBBS, El
UN W-17060 Volume Calculation 2/20/2018
(TOTAL VOLUME OF FACILITY
Volume of Main Pool below Normal Pool=
178,984
cf
Volume of Exiting Forebay below Normal Pool =
47,360
IT
Volume of Proposed Forebay #1 below Normal Pool =
26,329
cf
Volume of Pi oposed Forebay 42 below Normal Pool =
2,729
Total Volume of Forebays below Normal Pool=
76,418
cf
Total Volume Below Normal Pool
255,402
cf
Total Volume Above Normal Pool=
337,000
cf
Total Volume of Facility =
592,401
Cf
iFOREBAY PERCENTAGE OF PERMANENT POOL VOLUME
—,
Per NCDEQ Minimum Design Criteria, the forebay volume should equal
opproxinialely 15.20% of the main pool volume.
Iota] Main Pool Volume=
178,984
Cf
Total Provided Forebay Volume=
76,418
cf
Provided Existing Forebay Volume %=
265%
Provided Proposed Forebays Volume%=
16.2%
Total Provided Forebay Volume%=
42.7%
tADDITIONAL FOREBAY VOLUME CALCULATIONS
20% of Main Pool Volume =
35,797
cf (forebay volume required per the NCDEQ Minimum Design Giteria)
Total Drainage Area to the SCM =
1,218,903
sf
Existing Forebay DA=
837,646
sf
Existing Forebay DA/Tatal DA=
0.69
Forebay Volume Required for Proportion of DA=
24,500
cf
Existing Foreboy Provided Volume=
47,360
cf
Proposed Forebay 91 DA =
272,877
sf
Proposed Forebay 01 DA/Total DA =
0.22
Forebay Volume Required for Proportion of DA=
8,014
cf
Proposed Forebay#1 Provided Volume=
26,329
cf
Proposed Forebay #2 DA =
51,947
sf
Proposed Forebay #2 DA/Total DA=
0.04
Forebay Volume Required for Proportion of DA =
1,526
cf
Proposed Foreboy 92 Proviced Volume =
2,729
rf
'AVERAGE DEPTH OF MAIN POOL
Volume of Main Pool at Permanent Pool =
178,984
cf
Surface Area of Main Pool at Permanent Pool =
31,275
if
Average Depth=
5.72
ft
FEB 2 2 '63 3
BY-

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UNW-17060 Surface Area Calculation
R. STUBBS, El
2/9/2018
,WET DETENTION BASIN SUMMARY
Enter the drainage area characteristics =_>
Total drainage area to pond = 27.98 acres
Total impervious area to pond = 13.96 acres
Note The basin must be sized to treat all impervious surface runoff draining into the pond, notjust the impervious
surface from on -site development.
Drainage area = 27.98 acres @ 49.9% impervious
Estimate the surface area required at pond normal pool elevation ==>
Wet Detention Basins are based on an minimum average depth of =
5.72 feet (Calculated)
5.0
5.72
6.0
Lower Boundary=> 40.0 1.83
1.39
Site % impervious => 49.9 2.35
1.97
1.83
Upper Boundary=> 50.0 2.35
1.83
Therefore, SA/DA required =
1.97
Surface area required for main pool at normal pool =
24,008
ft'
=
0.55
acres
Surface area provided for main pool at normal pool =
31,275
ft'
Temporary Pool Elevation =
34.30
ft
Temporary Pool Surface Area =
73,139
ft
NCDEQ Stormwater BMP Manual Table 2: Coastal SA/DA Table (Adapted from Driscoll, 1986)
3
4
5-
6
7
8
10
0.78
0.61
0.44
0
0
0
20
1.48
1.04
0.87
0.7
0.52
0.35
30
2.18
1.65
1.39
1.13
0.87
0.7 '
40
2.96
2.26
1.83
1.39
0.96
0.78.
50
3.65
2.87
2.35
1.83
1.31
1.96
60
4.35
3.31
2.78
2.26
1.74
1.13
70
5.22
3.92
3.22
2.52
i 1.83
1.31
80
5.92
4.52
3.65
2.78
1.91
1.57
90
6.53
5.05
4.18
2.96
2.44
1.74
100
7.13
5.92
4.87
3.83
2.78
1.83

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE R. STUBBS, El
UN W-17060 WQV Calculation 2/9/2018
DETERMINATION OF WATER QUALITY VOLUME
Proposed Development
WQ v = (p)(R v)(A)/12
where,
WQv=water quality volume (in acre-ft)
Rv=0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A = 812458 sf
Total Drain Area, A = 18.65 acres
Impervious area = 201844 sf
Impervious area = 4.63 acres
Percent impervious cover, I = 24.8 %
Rainfall, P= 1.50 inches
Calculated values:
Rv= 0.27
WQv= 0.64 acre-ft
= 27785 cf.
Previously Permitted 1988-2008
WQ v = (P)(R v)(A)/12
where,
WQv= water quality volume (in acre-ft)
Rv= 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A = 352597 sf
Total Drain Area, A= 8.09 acres
Impervious area= 352597 sf
Impervious area= 8.09 acres
Percent impervious cover, I = 100.0 %
Rainfall, P= 1.00 inches
Calculated values:
Rv= 0.95
WQv= 0.64 acre-ft
27914 cf.
(SW8 0605301

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE R. STUBBS, El
UN W-17060 WQV Calculation 2/9/2018
Previously Permitted 1008-2017
WQ v = (P)(R v)(A)/12
where,
WQv= water quality volume (in acre-ft)
Rv= 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A=
5952
sf
Total Drain Area, A=
0.14
acres
Impervious area=
5952
sf
Impervious area=
0.14
acres
Percent impervious cover, I =
100.0
%
Rainfall, P=
1.50
inches
Calculated values:
Rv=
0.95
WQv=
0.02
acre-ft
=
707
cf.
Existing Impervious Not Previously Permitted Pre 1988
WQ v = (P)(R v)(A)112
where,
WQv= water quality volume
(in acre-ft)
Rv= 0.05+0.009(I)
where
I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A=
14760
sf
Total Drain Area, A =
0.34
acres
Impervious area =
14760
sf
Impervious area =
0.34
acres
Percent impervious cover, I =
100.0
%
Rainfall, P=
1.50
inches
Calculated values:
Rv=
0.95
WQv=
0.04
acre-ft
=
1753
cf.
/S W8 0605301
(SW80605301

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
U N W-17060 WQV Colculation
R. STUBBS, El
2/9/2018
Other Permits 1988-1008 (1"Treated)
WQ v = (P)(R v)(A)112
where,
WQv= water quality volume
(in acre-ft)
Rv= 0.05+0.009(I) where
I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A = 13154
sf
Total Drain Area, A = 0.30
acres
Impervious area = 13154
sf
Impervious area = 0.30
acres
Percent impervious cover, I = 100.0
%
Rainfall, P= 1.00
inches
Calculated values:
Rv= 0.95
WQv= 0.02
acre-ft
= 1041
cf.
Other Permits 1008-1017 (1.5" Treated)
WQ v = (P)(R v)(A)I12
where,
WQv= water quality volume
(in acre-ft)
Rv= 0.05+0.009(I) where
I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total Drain Area, A = 10428
sf
Total Drain Area, A = 0.24
acres
Impervious area= 10428
sf
Impervious area = 0.24
acres
Percent impervious cover, I = 100.0
%
Rainfall, P= 1.50
inches
Calculated values:
Rv= 0.95
WQv= 0.03
acre-ft
= 1238
cf,
(S W8 031039]
(S W81004051

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UN W-17060 WQV Calculation
R. STUBBS, El
2/9/2018
Offsite (1.5" Treated) - includes ROW and Off-UNCW Property areas
WQ v = (P)(R v)(A)/12
where,
WQv= water quality volume (in acre-ft)
Rv= 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data. -
Total Drain Area, A =
9554
sf
Total Drain Area, A =
0.22
acres
Impervious area =
9554
sf
Impervious area =
0.22
acres
Percent impervious cover, I =
100.0
%
Rainfall, P=
1.50
inches
Calculated values:
Rv=
0.95
WQv=
0.03
acre-ft
=
1135
Cf.
ASSOCIATED DEPTH IN POND
WQv=
61573 cf.
Stage / Storage Data:
Ks =
b =
64810
.232 1.232
Zo =
33.30
Total WQv=
61573 cf.
Calculated values:
Depth of WQv in Basin =
0.96
it
=
11.51
inches
Elevation =
34.26
ft

UNCW HURST HAMILTON PARKING LOT STORMWATER CONTROL MEASURE
UNW-17060 WQV Drawdown Calculation
R. STUBBS, El
2/9/2018
DRAWDOWN WQ ORIFICE DESIGN
D orifice=
4 inch
p orifices =
1
Cd siphon=
0.60
Normal Pool Elevation =
33.30 feet
Volume @ Normal Pool =
0 cf
Orifice Invert=
33.30 feet
WSEL at Water Quality Volume= 34.26 feet
Water Quality Volume (Required Volume) = 61573 cf
WSEL at Temp Pool (Provided) = 34.30 feet
Orifice Equation:
%ram NC DEQ Stormwoter Design Monual Calculations Document"
Q= CDA(2"8*[Ho/3])0.5
Average driving head on orifice (Hd3) = 0.278 feet
Orifice composite loss coefficient (Co) = 0.600
Cross -sectional area of siphon (A) = 0.087 sf
Q= 0.2215 cfs
Drawdown Time = Required Volume / Flowrate / 86400 (sec/day)
Drawdown Time= 3.22 da s

Hall, Christine
From: Hall, Christine
Sent: Friday, February 09, 2018 136 PM
To: 'Perry, Daniel'
Cc: Stubbs, Rebecca; Riggins, Daryl
Subject: RE: lExternal] Hurst Hamilton Parking Lot (SW8 060S30)
An extension until February 14' is fine with me. Thanks for the e-mail!
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources - State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
[e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405
<> Nothing Compares -
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel imailto:[e-mail]]
Sent: Friday, February 09, 2018 1:28 PM
To: Hall, Christine <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>; Riggins, Daryl <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
Christine,
I would like to formally request an extension for the request for additional information for the Hurst Hamilton Parking
Lot project (SW8 060S30). With limited resources available this past week, we need additional time to fully prepare the
package for you. I would appreciate an extension to Wednesday, February 14`h. Thank you for your help with this.
Thank you,
Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x134 I direct 919. 287. 0795 1 mobile [phone] [e-mail]

www.mcadamsco.com I linkedin I twitter I instaeram I Join our team
�JI MCA.DAMS
creating experiences through experience
From: Hall, Christine[mailto:Christine.Hall @ncdenr.eov]
Sent: Friday, February 9, 2018 8:20 AM
To: Perry, Daniel <dperry mcadamsco.com>
Cc: Stubbs, Rebecca <[e-mail]>
Subject: RE: [External] Hurst Hamilton Parking Lot (SW8 060530)
Item l.b — I'm referring to the drainage area divide identified in-between those two arrows.
Item 2.b —You are missing the point. The proposed forebays are oversized as well for their drainage areas. Forebays are
required to be 15%to 20%of their contributing drainage area. If this can't be met, then justification for this variation
must be provided.
Item 3 — Please provide that calculation to demonstrate.
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
Christine. hall(a�ncdenr.gov
127 Cardinal Drive Ext.
Wilmington, INC 28405
:'%'Nothing Cornpares
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel [mailto:[e-mail]]
Sent: Thursday, February 08, 2018 3:12 PM
To: Hall, Christine <[e-mail]>
Cc: Stubbs, Rebecca <[e-mail]>
Subject: [External] Hurst Hamilton Parking Lot (SW8 060530)
o External email:,Do. not click Links oropen attachments unlessverified. Send all suspicious emaiG.as an=attachment to" �;
Re ort5 alnx •--ws`.Fl.. �, .J, u^.....= k n�.x r9
Christine,
Good Afternoon! See below for questions and responses to your request for additional information. Please let me know
your thoughts and we will get this one back to you for approval. Thanks for your help!
1. 15A NCAC 02H.1042(2)(g)(iv): Please provide additional proposed contours on sheets C10 and C11 to support the
identified drainage areas and patterns in the following areas:

a. The intersection of Hurst Drive and Hamilton Drive.
McAdams Response: Contour labels have been added to clarify the drainage area in this location
b. The sidewalk high point off McMillan Ave near the pump station.
McAdams Response: Which location are you referring to?
There is a slope call out that shows the drainage directed away from the road, as requested during the
express review.
Or
3

EX FIBER OP'n
CABI.,E (TYP.) Ci
ti / ��j:�i�•. i. •rY:S''I !. tom, a.�'j�.���tS
1i...yak:� \ y:ti,SJr''•.;xy;,!ii^ `tii:i; :r jai•!.
j C`j� �:r: r r li ��:.: ii•'r•f i �r + I '
jfjj � � _ `✓T .� ii:.; � (t+" / ry'(:`;, ..v�%i: ih'� t:cr �,?ti.
+ ..v�:S�i°,•a'l,+r;.T,',.., q..i}:• t :+:i:;),.a-f�i- `
''��� i � ��./� �i`.j•LT:•.trriL.::(. .1(... . rti iY S3.l..: .iy..:'aia
I '�� II: �— — !p\�^�:'•.�•'ii)::<raj:.<!i �_, ..�::��^,�.tY.-i:.Iti.. �=t=:7: "r'�'�
r ►����� ij111 -;i1l, HrJI : jt�
Portions of this side walk that can't be drained to the parking lot will sheet flow into the SCM.
c. The west parking lot access drive on McMillian Ave.
McAdams Response: The drainage area will be adjusted to move the high point to the blue line represented
below. All calculations will be adjusted accordingly.
N
2. 15A NCAC 02H.1053(5):.
a. The sum of the forebay drainage areas presented in the calculations is less than the total drainage area to
the pond. Please explain the difference.
McAdams Response: There are some areas within the overall drainage area to the SCM that overland flow
into the Main Pool. The size of these areas has been reduced from the existing condition in the proposed
9

layout, as all concentrated discharges resulting from the proposed development are directed into one of the
forebays to receive pretreatment prior to entering the main pool portion of the SCM.
b. In reviewing the calculations for sizing the individual forebay volumes, it appears that each of the three
forebays (existing and proposed) exceed 20% of its area weighted volume in the main pool. 15A NCAC
02H.1053(5)(a) requires the forebay volume to be 15 to 20% of the volume in the main pool. Please either
reconsider the size of the three forebays or provide justification for the variations in accordance with 15A
NCAC 02H.1003(6)
McAdams Response: Language has been added to the narrative to discuss the matter. The forebay volume
provided in the SCM is in excess of the 15-20% required volume. This is in large part due to the contribution
of volume of the existing forebay, in addition to providing forebays for each of the proposed concentrated
discharges into the SCM. While the total forebay volume exceeds the MDC requirement, the main pool
remains significantly oversized per the surface area calculation using the SA/DA method. Therefore, this
SCM is providing better treatment than the minimum requirement stated in 15A NCAC 02H .1053(5)(a).
3. 15A NCAC 02H.1003(1)(b): In Attachment A, the existing, pre-1988 built upon area is not included in the total BUA
for the site. Please demonstrate that the project area used for this drainage area meets either 15A NCAC
02H.1003(1)(a) or .1003(1)(b).
McAdams Response: The project area was determined using the method described in 15A NCAC 02H .1003
(1)(b). The existing, pre-1988 BUA in the low density portion of this permit was subtracted from the total
BUA and the total project area within that drainage area to determine project density.
Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x134 ) direct 919. 287. 0795 1 mobile [phone] ( [e-mail]
www.mcadamsco.com I linkedin I twitter I instagram (loin our team
1111 MCADAMS
creating experiences through experience

Energy. Mineral &
Land Resources
ENVIRONMENTAL QUALITY
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
WILLIAM E. (TOBY) VINSON, JR.
Interim Director
Pebruary 2, 2018
a�ah t�
UNC Wilmington
Attn: Vice Chancellor for Business Affairs
c/o Mark Morgan. Associate Vice Chancellor for Business Affairs -Facilities
601 S. College Rd.
Wilmington, NC 28403
Subject: Bequest for Additional Information
Stormwater Project No. SV1'8 060530
Hurst Iamilton parking Lots
New Hanover County
Dear Mr. Morgan:
'fire Wilmington Regional Office received and accepted a modified Express State Stormwater
Management Permit Application for the subject project on January 16, 2018 with additional information
received on January 29, 2018. 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:
✓l. 15A NCAC 021-I.1042(2)(g)(iv): Please provide additional proposed contours on sheets CIO and
Cl 1 to support the identified drainage areas and patterns in the following areas:
ol, a. The intersection of Hurst Drive and Hamilton Drive
,b� The sidewalk high point off McMillan Ave near the pump station.
L—c' The west parking lot access drive on McMillian Ave.
Recommendation: 117 the case where the contour interval on a "topographic" map is too large to
adequately reflect the existing and proposed drainage patterns of a relatively flan property, spot
elevations and/or a sire -specific elevation survey may he needed.
2. 15A NCAC 02I-1.1053(5):
, . The sum of the forebay drainage areas presented in the calculations is less than the total
drainage area to the pond. Please explain the difference.
b. In reviewing the calculations for sizing the individual forebay volumes, it appears that
each of the three forebays (existing and proposed) exceed 20% of its area weighted
volume in the main pool. 15A NCAC 021-I.1053(5)(a) requires the forebay volume to be
15 to 20% of the volume in the main pool. Please either reconsider the sire of the three
forebays or provide justification for the variations in accordance with 15A NCAC
02I-1.1003(6).
Z3. 15A NCAC 021-I.1003(I)(b): In Attachment A, the existing, pre-1988 built -upon area is not
included in the total BUA for the site. Please demonstrate that the project area used for this
drainage area meets either 15A NCAC 021-I.1003(1)(a) or .1003(1)(b).
4. Due to the relatively minor nature of these comments, the express additional information review
fee has been waived.
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 02I-1.1042(2).
51ateof North Carolina I Enviionmental Qualify I Energy. Mineral and Land Resources
Wilmington Regional Office 1127 Cardinal Drive Extension I Wilmington, NC 28405
010 796 7215

State Stormwater Permit No. SW8 0605-,0
Page 2 of 2
The requested information should be received in this Office prior to February 12, 21118, or the
application will be returned as incomplete. Please note that only livo letters reguesling additional
information is allowed in the State Stormwater Program. If the information is not satisfactorily provided
after the second regUest, the project will be returned. If the project is returned and you wish to re -submit
to the Lxpress Program, you will need to reschedule the project through the Lxpress Coordinator for the
next available review date and will need to resubmit all required items at that time, including the
application fee.
If additional time is needed to submit the requested infornunion, please email your extension request,
prior to the original due data to the Division at the email address provided below. The extension request
must include a justification and a date of when the requested information will be submitted to the
Division, which shall be no later than 5 business days past the original due date. Please remember that
extension requests delay the issuance of the final permit.
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 \CGS 143-215.6A.
Please label all packages and cover letters as "Express" and 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 cliritsinc.11;[e-mail].
ncdenr.gov.
Sincerely,
Christine Hall
larvironmental Engineer
GDS/cash: %Stormwater-Termits & Projects\2006\060530 I lD\2018 02 addinfo 060530
cc: Galen Jamison, PE, Project Manager, UACW
Daryl Riggings, PE; McAdams
Wilmington Regional Office Stormwater Pile
State of North Carolina I GnviromnentaI Quality I Energy, Mineral and Land Resources
Wilmington Regional Office 1127 Cardinal Drive Extension I Wilmington, NC 28405
910 796 7215

Hall, Christine
From:
Hall, Christine
Sent:
Friday, February 02, 2018 3:28 PM
To:
'Riggins, Daryl'; '[e-mail]'
Cc:
Weaver, Cameron
Subject: RE: 2nd request for additional info- Hurst Hamilton Parking Lots, SW8 060530
Sorry Galen, I had a typo in your e-mail.
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
[e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405
`Nothing Compares..
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Hall, Christine
Sent: Friday, February 02, 2018 3:25 PM
To:'Riggins, Daryl' <[e-mail]>; Galin Jamison ([e-mail]) <[e-mail]>
Cc: Weaver, Cameron <[e-mail]>
Subject: 2nd request for additional info- Hurst Hamilton Parking Lots, SW8 060530
Daryl,
I have had a chance to review the revised items and there are just a few minor details that need to be addressed. A pdf
of the second request for additional information is attached. Please let me know if you have any questions.
Christine
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
christine. haII(cDncdenr.gov
127 Cardinal Drive Ext.
Wilmington, NC 28405

Kra
` ,Nothing Compares.
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Riggins, Daryl [maiIto: [e-mail]] ^
Sent: Friday, January 19, 2018 2:08 PM
To: Hall, Christine <[e-mail]>; Galin Jamison (jaimsong(@uncw.edu) <[e-mail]>
Cc: Weaver, Cameron <[e-mail]>
Subject: [External] RE: request for additional info- Hurst Hamilton Parking Lots, SW8 060530
CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
[e-mail].
Christine,
We're reviewing the comments and requests for information at this time. Thanks,
Daryl Riggins, PE i Project Manager, Institutional
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 i direct 919. 287. 0872 i mobile [phone] i [e-mail]
www.mcadamsco.com i linkedin i twitter ] instagram i loin our team
!!J1 MCADAMS
creating experiences through experience
From: Hall, Christine[maiIto:[e-mail]]
Sent: Friday, January 19, 2018 1:55 PM
To: Galin Jamison ([e-mail]) <[e-mail]>; Riggins, Daryl <[e-mail]>
Cc: Weaver, Cameron <[e-mail]>
Subject: request for additional info- Hurst Hamilton Parking Lots, SW8 060530
Gentlemen,
Attached is a pelf of the request for additional information for the modification to SW8 060530 to add the Hurst and
Hamilton Parking Lots. Please let me know of any questions or concerns.
Christine
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
christine. [e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405

3y.
-;"i Nothing Compares,
>f
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

'JI MCADAMs
Date: January 26, 2018
To: Ms. Christine Hall
Division of Energy, Mineral and Land Resources
State Stormwater Program
Department of Environmental Quality
127 Cardinal Drive Ext.
Wilmington, North Carolina 28405
I am sending you the following items:
❑ Drawings ❑ Letter
❑ Specifications ® Submittal
❑ Plans ❑ Prints
LETTER OF TRANSMITTAL
FEDERAL EXPRESS
Re: University of North Carolina - Wilmington
Hurst Hamilton Parking Lots
Stormwater Management Plan
Job#t: UNW-17060
❑ Statement of Qualifications
❑ Other
QUANTITY
UNIT
DESCRIPTION
1
Copy
Stormwater Impact Analysis
1
Check
Express Re -Review Fee $500.00
1
Set
SCM O&M Form
1
Set
SCM Supplement Form
1
Set I
Stormwater Permit Application 1 Original & 1 Copy
2
Sets
Construction Drawings
1
Copy
Response to Comments'letter
Transmitted as checked below:
® Forapproval
❑ For your use
❑ As requested
Remarks:
Copy to:
❑ For review + comment
❑ Other
❑ Other
r
Signature:
Dart
Project Manager, Water Resources
creating experiences through experience 2905 Meridian Parkway, Durham, NC 277131919. 361. 5000

'J MCADAMS
January 26, 2018
State of North Carolina
Environmental Quality, Wilmington Regional Office
127 Cardinal Drive Extension
Wilmington, North Carolina 28405
RE: Hurst Hamilton Parking Lots
Response to Preliminary NCDEQ Comments
McAdams Project: UNW-17060
RESPONSE TO COMMENTS > UNW-17060
OEIIVE
JAM 2 9 2018
The following are the response comments for the above -mentioned project. Our response comments are in bold.
NCDEQ:
Christine Hall, Environmental Engineer, 910. 796. 7215
1. 15A NCAC 02H.1042(2)(a)(iv) and .1042(2)(f): Please confirm the following project information:
a. In Attachment A, please provide a project area associated with the redevelopment exemption column.
McAdams Response: The project area of the redevelopment exemption has been provided in
Attachment A. It was assumed that the project area is equal to the impervious area that is considered
the redevelopment exemption.
b. The redevelopment exemption column in Attachment A should only include the proposed amount of built -
upon area (BUA), not the existing too. Please remove the 14,760 sf from that column.
McAdams Response: The redevelopment exemption column now only includes the proposed BUA.
c. The total column in Attachment A does not include the redevelopment exemption column. Please include
all areas covered under this permit.
McAdams Response: The total column of Attachment A has been revised to include all areas covered
under the permit.
In the impervious surface area section of Attachment A, please clarify the three labels directly beneath
SW8 100405 by providing a more descriptive label. The references are confusing and doesn't help to
identify the source of the BUA.
McAdams Response: A relative location has been added to the description of the categories of
impervious surface in Attachment A mentioned above.
creating experiences through experience 2905 Meridian Parkway, Durham, NC 27713 / 919. 361. 5000

M WADAMS
RESPONSE TO COMMENTS > UNW-17060
e. This system was previously approved to allow 6,000 square feet of offsite runoff to be treated at the 1"
design storm. Any additional offsite area captured due to the expanding drainage area must be treated at
the current design storm. Please reconsider the minimum required volume for this offsite area.
McAdams Response: All offsite areas draining to the SCM have been revised to be treated to the
current design storm (1.5"). Pleaser refer to the WQ Volume calculations in Section 6 of this report.
The sum of the drainage areas presented in the calculations to determinate the water quality volume
appears to be 14,760 square feet in excess of the drainage area presented in the other application
documents. Additionally, the total wet pond drainage area presented in the wet pond supplement is not
consistent with the total drainage area presented in Attachment A. Please confirm the drainage area to
the pond.
McAdams Response: The drainage area to the pond has been revised to be consistent across all
reporting forms. The total drainage area in the WQ volume calculations has been corrected.
2. 15A NCAC 02H.1042(2)(g)(iii): Please provide the boundaries of all surface waters, wetlands, regulatory flood
zones, protected vegetated setbacks, and protected riparian buffers, or a note on the plans that none exist. If
this note is already on the plans, please provide a citation to find it.
McAdams Response: A note has been added to the Existing Conditions survey (sheet C-1).
3. 15A NCAC 02H.1042(2)(g)(iv): Please provide additional proposed contours to support the identified drainage
areas and patterns. Recommendation: In the case where the contour interval on a "topographic" map is too
large to adequately reflect the existing and proposed drainage patterns of a relatively flat property, spot
elevations and/or a site -specific elevation survey may be needed.
McAdams Response: Please cross reference sheets C-10 and C-11 for detailed spot shots to support the
drainage areas delineated on the drainage area and BUA map. The scale of the DA and BUA map does
not allow for clarity in adding spot shots.
4. 15A NCAC 02H.1042(2)(g)(iv) and (vii): Two vegetated islands along Hamilton Drive use concrete flumes to
direct runoff, however, these islands and the concrete flumes are not included in the drainage area. Please
confirm that the delineated drainage area considers all stormwater collection features proposed.
McAdams Response: The drainage area to the pond has been revised to accurately reflect the drainage
patterns within each of the parking lots.
5. 15A NCAC 02H.1042(2)(h): Sheet SW-2 includes cross section views of the various pond features except
forebay #2. Please provide a cross-section view of forebay #2.
McAdams Response: A cross-section view of Proposed Forebay #2 has been added to sheet SW-2.
6. 15A NCAC 02H.1050(4): Please provide details on the outlet protection proposed for EW-300 on sheet C-11.
McAdams Response: A callout with sizing dimensions has been provided on sheet C-11.
creating experiences through experience 2 of 5

u
'J MCADAMS
RESPONSE TO COMMENTS > UNW-17060
15A NCAC 02H.1050(12): The provided operation and maintenance agreement does not include the
information for the existing forebay. Please include the existing forebay in the operation and maintenance
agreement.
McAdams Response: The existing forebay information from the previously approved O&M has been
added to the Operation and Maintenance Manual.
8. 15A NCAC 02H.1053(1) and (2): The main permanent pool volume and average depth presented in the
supplement is not consistent with the values listed in the calculations. Please confirm.
McAdams Response: The supplement has been revised to be consistent with the SCM calculations
provided in Section 6 of this report.
15A NCAC 02H.1053(5):
a. The narrative notes that the exiting forebay will remain unaltered. However, the design and calculations
are not consistent with the originally approved forebay design. This forebay was approved during a time
when the entire forebay, including the sediment storage, was used to determine the volume available in
the forebay. The calculations provided in 2006 indicate that the volume of this forebay was determined
using the following equation:
(18,775 + 5,610) / 2 * 5 ft = 60,962 ft3.
The submitted stage -storage calculations for this existing forebay do not consider the full 5-foot depth If it
is desired to maintain the original design, then please re -consider the stage storage table to include the
same characteristics as originally permitted. However, if it is desired to permit this forebay under the 2017
requirements, then please either ensure the forebay meets the requirements of 15A NCAC 02H.1053 or, if
not all of the requirements can be met, provide justification for the variations per 15A NCAC 02H.1003(6).
Depending on the elevation of the pipes connecting the existing forebay to forebay #1, another option
under the 2017 rules might be to consider these two as a single, hydrologically connected forebay.
McAdams Response: The narrative has been revised to state that a stage storage function was
generated for the existing forebay using survey of current conditions provided by Avioimage.
b. The accumulated volumes listed in the stage storage table for Forebay #2 are not consistent with the
incremental volumes. Please confirm the calculation for the accumulated volume.
McAdams Response: The calculation of the accumulated volumes has been corrected.
c. Please provide calculations demonstrating that the forebays have been sized to handle 15%to 20% of
their respective contributing drainage areas.
McAdams Response: See revised calculations regarding the provided forebay volume. The total
forebay volume provided exceeds the requirement per the MDCs. To ensure that each forebay was
creating experiences through experience
3 of

11111
= McADAMS
RESPONSE TO COMMENTS > UNW-17060
proportionally sized to handle its respective drainage area, the required forebay volume (20% of the
main pool volume) was determined and then proportionally split between the forebays based on their
drainage areas. For each forebay, the volume provided exceeds this calculated minimum.
d. The forebay volume listed in the supplement is not consistent with the forebay volumes listed in the
calculations. Please confirm.
McAdams Response: The forebay volume has been corrected to be consistent on all forms.
The supplement lists the depth of the forebay at the entrance and exit as being 87.6 inches or 7.3 ft and
the cleanout depth as 82 inches or 6.8 ft. However, none of the proposed forebays appear to be that
deep. Also, the MDC requires the entrance to be deeper than the exit. Please confirm the forebay design
meets the requirements of 15A NCAC 02H.1053(5)(b) and that the information is presented consistently
and accurately.
McAdams Response: The supplement form has been revised to more clearly show the entrance and
exit depths for each of the forebays.
10. 15A NCAC 02H.1053(6): The supplement lists the top of the vegetated shelf as being set at an elevation of 34.3
ft but Sheet SW-1 and SW-3 lists the top as 34.5 ft. Please confirm the top elevation of the vegetated shelf.
McAdams Response: The callouts on SW-1 and SW-3 have been corrected to reflect 34.30 as the top of
shelf elevation.
11. 15A NCAC 02H.1053(7) and .1002(10):
a. The supplement, calculations, and other application documents indicate that the temporary pool elevation
is set at 34.27 ft; however, the outlet structure detail on plan sheet SW-2 indicates that the next available
outlet is set at 34.30 ft. The design volume of a wet pond is contained between the permanent pool
elevation and the elevation of the next available outlet. This next available outlet is considered to be the
temporary pool elevation. Please reconsider the elevation of the temporary pool and ensure it is
presented consistently.
McAdams Response: The temporary pool elevation has been updated in the calculation book and the
construction drawings to be 34.30, the invert of the next overflow orifice.
b. The supplement identifies the design volume as being 64,910 cf, however, calculations could not be found
to support that volume. The stage -storage table demonstrates that the volume stored at an elevation of
34.3 ft is 66,951 cf. Once the temporary storage elevation is confirmed, please ensure to provide
calculations to support the volume stored at that elevation.
McAdams Response: The design volume has been revised in the calculations to reflect the storage
volume in the pond at the temporary pool elevation (34.30).
creating experiences through experience 4 of 5

iJ MCADAMS
RESPONSE TO COMMENTS > UNW-17060
c. The drawdown chart starts at an elevation of 34.3 ft however the identified volume stored at this
elevation, 64,810 cf, is not consistent with the storage volume presented at this elevation in the stage -
storage table for above the normal pool. Please confirm the drawdown calculations are based on the
provided pond design.
McAdams Response: The drawdown calculations have been simplified for more clarity.
12. N.C.G.S. 143-214(c3): If the project is within 5 statute miles of a public airport, the Division cannot require the
use of a BMP with a permanent pool of water. A copy of the permit will be forwarded to the airport's director
who may elect to adjudicate the permit if the applicant has chosen to use a BMP with a permanent pool of
water.
McAdams Response: Noted.
13. Due to the insufficiency of the application, please submit a $500 fee for the additional review required for this
application (in accordance with Session Law 2003-284, Section 11.4A(b)).
McAdams Response: A check for the additional review fee has been provided.
Consideration of this response is greatly appreciated. If you should have any questions or require additional
information, please do not hesitate to contact me at 919. 361. 5000.
Sincerely,
MCADAMS
Daniel Per ,
Project Manager, Water Resources
DP/hc
creating experiences through experience 5 of 5

Energy. Mineral &
Land Resources
ENVIRONMENTAL QUALITY
January 19, 2018+�
UNC Wilmington 2�a\
Attn: Vice Chancellor for Business Affairs
c/o Mark Morgan, Associate Vice Chancellor for Business Affairs -Facilities
601 S. College Rd.
Wilmington, NC 28403
Subject: Request for Additional Information
Stormwater Project No. SWS 060530
Ilurst Hamilton Parking Lots
New Hanover County
Dear Mr. Morgan:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
TRACY DAVIS
Director
\ W\2i
The Wilmington Regional Office received and accepted a modified Express State Stormwater
Management Permit Application for the subject project on January 16, 2018. 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:
1. 15A NCAC 021-I.1042(2)(a)(iv) and .1042(2)(0: Please confirm the following project
information:
In Attachment A, please provide a project area associated with the redevelopment
! exemption column.
✓b. The redevelopment exemption column in Attachment A should only include the proposed
amount of built -upon area (13UA), not the existing too. Please remove the 14,760 sf from
that column.
,,,'c. The total column in Attachment A does not include the redevelopment exemption
column. Please include all areas covered under this permit.
I/d. In the impervious surface area section of Attachment A, please clarify the three labels
directly beneath SW8 100405 by providing a more descriptive label. The references are
confusing and doesn't help to identify the source of the BUA.
✓c. "I'his system was previously approved to allow 6,000 square feel of offsite runoff to be
treated at the 1" design storm. Any additional offsite area captured due to the expanding
drainage area must be treated at the current design storm. Please reconsider the
/ minimum required volume for this offsite area.
`/f. The sum of the drainage areas presented in the calculations to determinate the water
quality volume appears to be 14,760 square feet in excess of the drainage area presented
in the other application documents. Additionally, the total wet pond drainage area
presented in the wet pond supplement is not consistent with the total drainage area
presented in Attachment A. Please confirm the drainage area to the pond.
/. 15A NCAC 021-I.1042(2)(g)(iii): Please provide the boundaries of all surface waters, wetlands,
regulatory flood zones, protected vegetated setbacks, and protected riparian buffers, or a note on
the plans that none exist. If this note is already on the plans, please provide a citation to find it.
I tiA u"LeAra^
3. 15A NCAC 021-1.1042(2)(g)(iv): please provide additional proposed contours to support the
identified drainage areas and patterns. Recommendation. In the case where the contour interval
on a "topographic" map is too large to adequately reflect the existing and proposed drainage
AE�:�atternS of a relatively flat property, spot elevations and/or a site -specific elevation survey may
vo s, \tin. ?,v be needed.
'ica\o.. G...morn :\\c-•
State of North Carolina I Environmental Quality I Energy, Mineral and Land Resources
Wilmington Regional office 1127 Cardinal Drive Extension I Wilmington, NC 28405
910 796 7215

State Stormwater Permit No. SW8 060530
Page 2 of 3
t/4. 15A NCAC 0211.1042(2)(g)(iv) and (vii): Two vegetated islands along Hamilton Drive use
concrete flumes to direct runoff; however, these islands and the concrete flumes are not included
in the drainage area. Please confirm that the delineated drainage area considers all stormwater
collection features proposed.
_,,5� 15A NCAC 021-1.1042(2)(h): Sheet S\N-2 includes cross section views of the various pond
features except forebay H2. Please provide a cross-section view of forebay 412.
�/O. 15A NCAC 021-1.1050(4): Please provide details on the outlet protection proposed for GW-300
on sheet C-1 I.
J7. 15A NCAC 0211.1050(12): -fhe provided operation and maintenance agreement does not include
the information for the existing forebay. Please include the existing forebay in the operation and
maintenance agreement.
/8. 15A NCAC 021-1.1053(1) and (2): The main permanent pool volume and average depth presented
in the supplement is not consistent with the values listed in the calculations. Please confirm.
9. 15A NCAC 021-1.1053(5):
'fhe narrative notes that the exiting forebay will remain unaltered. However, the design
and calculations are not consistent with the originally approved forebay design. -]'his
forebay was approved during a time when the entire forebay, including the sediment
storage, was used to determine the volume available in the forebay. The calculations
provided in 2006 indicate that the volume of this forebay was determined using the
following equation:
(18,775 + 5,610) / 2 * 5 ft= 60,962 ft'.
The submitted stage -storage calculations for this existing forebay do not consider the full
5-foot depth If it is desired to maintain the original design, then please re -consider the
stage storage table to include the same characteristics as originally permitted. however, if
it is desired to permit this forebay under the 2017 requirements, then please either ensure
the forebay meets the requirements of 15A NCAC 0211.1053 or, if not all of the
requirements can be met, provide justification for the variations per 15A NCAC
021-1.1003(6). Depending on the elevation of the pipes connecting the existing forebay to
forebay Nl, another option under the 2017 rules might be to consider these two as a
// single, hydrologically connected forebay.
I/o. The accumulated volumes listed in the stage storage table for Porebay 42 are not
consistent with the incremental volumes. Please confirm the calculation for the
accumulated volume.
7 c. Please provide calculations demonstrating that the forebays have been sired to handle
/ 15% to 20% of their respective contributing drainage areas.
✓d. The forebay volume listed in the supplement is not consistent with the forebay volumes
listed in the calculations. Please confirm.
The supplement lists the depth of the forebay at the entrance and exit as being 87.6 inches
or 7.3 ft and the cleanout depth as 82 inches or 6.8 ft. I lowever, none of the proposed
forebays appear to be that deep. Also, the MDC requires the entrance to be deeper than
the exit. Please confirm the forebay design meets the requirements of 15A NCAC
021-1.1053(5)(b) and that the information is presented consistently and accurately.
10. 15A NCAC 0211.1053(6): The supplement lists the top of the vegetated shelf as being set at an
elevation of 34.3 ft but Sheet SW-1 and SW-3 lists the top as 34.5 ft. Please confirm the top
elevation of the vegetated shelf.
11. 15A NCAC 021-1.1053(7) and .1002(10):
✓a. The supplement, calculations, and other application documents indicate that the
temporary pool elevation is set at 34.27 ft; however, the outlet structure detail on plan
Sheet SW-2 indicates that the next available outlet is set at 34.30 ft. The design volume
of a wet pond is contained between the permanent pool elevation and the elevation of the
next available outlet. This next available outlet is considered to be the temporary pool
elevation. Please reconsider the elevation of the temporary pool and ensure it is presented
consistently.
State of North Carolina I Environmental Quality I Energy. Mineral and Land Resources
Wilmington Regional Office 1127 Cardinal Drive Extension I Wilmington, NC 28405
910 796 7215

State Stormwater Permit No. S\v8 060530
Page 3 of 3
b. The supplement identifies the design volume as being 64,910 cf; however, calculations
could not be found to support that volume. The stage -storage table demonstrates that the
volume stored at an elevation of 34.3 fi is 66,951 cf'. Once the temporary storage
elevation is confirmed, please ensure to provide calculations to support the volume stored
at that elevation.
f. The drawdown chart starts at an elevation of 34.3 Ft however the identified volume stored
at this elevation, 64,810 cf, is not consistent with the storage volume presented at this
elevation in the stage -storage table for above the normal pool. Please confirm the
drawdown calculations are based on the provided pond design.
o�c­ 12. N.C.G.S. 143-214(c3): If the project is within 5 statute miles of a public airport, the Division
cannot require the use of a 13NIP with a permanent pool of water. A copy of the permit will be
forwarded to the airport's director who may elect to adjudicate the permit if the applicant has
chosen to use a 13MP with a permanent pool of water.
✓13. Due to the insufficiency of the application, please submit a S500 fee for the additional review
required for this application (in accordance with Session Law 2003-284, Section 1 1.4A(b)).
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 02I-1.1042(2).
The requested information should be received in this Office prior to January 29, 2017, or the application
will be returned as incomplete. If the project is returned and you wish to re -submit to the Express
Program, you will need to reschedule the project through the Express Coordinator for the next available
review date and will need to resubmit all required items at that time, including the application fee.
If additional time is needed to submit the requested information, please email your extension request,
prior to the original due dale, to the Division at the email address provided below. The extension request
must include a justification and a date of when the requested information will be submitted to the
Division, which shall be no later than 5 business days past the original due date. Please remember that
extension requests delay the issuance of the final permit.
The construction of any impervious surfaces, other than a construction entrance under an approved
Sedimentation Erosion Control Plan, is a violation ofNCGS 143-215.1 and is subject to enforcement
action pursuant to NCGS 143-215.6A.
Please label all packages and cover letters as "Express" and 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, �j_k
Christine Hall
Environmental Engineer
GDS/canh: \\\Stormwater\Permits & Projects\2006\060530 HD\2018 01 addinfo 060530
cc: Galen Jamison, PI:, Project Manager; UNCW
Daryl Riggings, PF" McAdams
Wilmington Regional Office Stormwater Pile
State of Nonh Carolina I Environmental Quality I Energy. Mineral and Land Resources
Wilmington Regional Office 1127 Cardinal Drtve Extension I Wilmington, NC 28405
910 796 7215

Hall, Christine
From:
Hall, Christine
Sent:
Friday, January 19, 2018 1,55 PM
To:
Galin Jamison [e-mail]), Riggins, Daryl
Cc:
Weaver, Cameron
Subject:
request for additional info- Hurst Hamilton Parking Lots, SW8 060530
Attachments:
2018 01 addinfo 060530.pdf
Gentlemen,
Attached is a pdf of the request for additional information for the modification to SW8 060530 to add the Hurst and
Hamilton Parking Lots. Please let me know of any questions or concerns.
Christine
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources - State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
[e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405
Nothing Compares.. -
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

IJ MCADAMS
Date: January 15, 2018
To: Ms. Christine Hall
Division of Energy, Mineral and Land Resources
State Stormwater Program
Department of Environmental Quality
127 Cardinal Drive Ext.
Wilmington, North Carolina 28405
I am sending you the following items:
❑ Drawings ❑ Letter
❑ Specifications ® Submittal
❑ Plans ❑ Prints
LETTER OF TRANSMITTAL
FEDERAL EXPRESS
Re: University of North Carolina- Wilmington
Hurst Hamilton Parking Lots
Stormwater Management Plan
Job #: UNW-17060
❑ Statement of Qualifications
❑ Other
QUANTITY
UNIT
DESCRIPTION
1
Copy
Stormwater Impact Analysis
1
Check
Express Review Fee $4,000
1
Set
SCM O&M 1 Original & 1 Copy
1
Set
SCM Supplement Form 1 Original & 1 Copy
1
Set
Stormwater Permit Application 1 Original & 1 Copy
2
Sets
Construction Drawings
1
CD
Digital Copy Tn be T/hsc/ a m4441
Transmitted as checked below:
® Forapproval
❑ Foryouruse
❑ As requested
Remarks:
Copy to:
❑ For review + comment
❑ Other
❑ Other
GE
Signature: 1�
Daniel Perry, PE
Project Manager, Water Resources
creating experiences through experience 2905 Meridian Parkway, Durham, NC 27713 / 919. 361. 5000

Hefl, Christine
From: Hall, Christine
Sent: Wednesday, November 29, 2017 2:13 PM
To: 'Perry, Daniel'
Cc: Riggins, Daryl
Subject: RE: [External] UNCW Hamilton -Hurst Parking Lot Construction Access
Since a pipe is proposed to be installed 1 foot off the bottom, I don't have a problem with that during construction. But
you may want to check with EC to see if they have any comments.
Christine Hall
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7335 direct
[e-mail]
127 Cardinal Drive Ext.
Wilmington, NC 28405
- '>,Nothing Compares
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Perry, Daniel [mailto:[e-mail]]
Sent: Tuesday, November 28, 2017 1:18 PM
To: Hall, Christine <[e-mail]>
Cc: Riggins, Daryl <[e-mail]>
Subject: [External] UNCW Hamilton -Hurst Parking Lot Construction Access
ICAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
[e-mail].
Christine,
I hope you had a great thanksgiving. We are looking into an alternate construction access path for the west lot instead of
using MacMillan Ave. Please see the below image which shows our use of a proposed forebay berm to provide access
during the construction phase of the project from the east lot. Since we are already regrading the facility to meet
current MDC rules, it is our hope that this path will be acceptable during construction. Please let me know of any
concerns or rules preventing this. I'm happy to discuss via phone if that works best.

Thanks for your help,
Daniel Perry, PE I Project Manager, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x134 I direct 919. 287. 0795 1 mobile [phone] [e-mail]
www,mcadamsco.com I linkedin I twitter I instazram I join our team
2 MCADAMs
creating experiences through experience
2

For DE0 Use ONLY
W
Reviewer.
North Carolina Department of Environmental Quality $emsit
Request for Express Permit Review
Tme'.
coofem: _✓
FILL-IN all the information below and CHECK the Permit(s) you are requesting for express review. Call and Email the completed form to the
Permit Coordinator along with a completed DETAILED narrative, site plan (PDF file) and vicinity map (same items expected in the application
package of the project location. Please include this form in the application package.
• Asheville Region -Alison Davidson 828-296.4698;alison.davidson(a)ncdenr.gov
• Fayetteville or Raleigh Region -David Lee 919-791-4203; david.lee(aMcdenr.gov
• Mooresville or Winston Salem -Marcia Allocco 704-235-2107; marcia.allocco(a)ncdenrgov
• Washington Region -Lyn Hardison 252-948-3842 or Ivn.hardison@)ncdenr.gov
• Wilmington Region -Cameron Weaver910-796-7303 orcameron.weaver(cimcdenri
NOTE: Project application received after 12 noon will be stamped in the following work day.
Project Name: HURST HAMILTON PARKING LOTS County: NEW HANOVER
Applicant: GALEN JAMISON Company: UNCW
Address: 601 S COLLEGE ROAD City: WILMINGTON, Slate: NC Zip: 28403
Phone: [phone]. Fax: _ _ Email: jam1 [e-mail]
Physical Location INTERSECTION OF HAMILTON & HURST
related to this Project
SW 8060530
SW_
SW _
NPDES _
NPDES _
WO _
WO _
E&S _
E&S _
Other
Project Drains into BURNT MILL CREEK waters — Water classification C:SW (DWR Surface Water Classifications Map)
Project Located in CAPE FEAR River Basin. Is project draining to class ORW waters? NO. within X,, mile and draining to class SA waters NO or within 1
mile and draining to class HOW waters? NO
Engineer/Consultant: DARYL RIGGINSCompany: MCADAMS
Address: 2905 MERIDIAN PARKWAY City: DURHAM, State: NC Zip: 27713-
Phone: [phone], Fax: [phone], Email: [e-mail]
PLEASE PROVIDE ESTIMATED INVESTMENT AND EXPECTED EMPLOYMENT, IF AVAILABLE
S_ #_JOBS rn.1 yy
SECTION ONE: REQUESTING A SCOPING MEETING ONLY
❑ Scoping Meeting ONLY ❑ DWR, ❑ DCM, ❑ DEMLR, ❑ OTHER:
e./
SECTION TWO: CHECK ONLY THE PROGRAM (S) YOU ARE REQUESTING FOR EXPRESS PERMITTING
❑ 401 Unit ❑Stream Origin Determination: _ # of stream calls —Please attach TOPO map marking the areas in question's
❑ IntermittentlPerennial Determination: _ # of stream calls — Please attach TOPO map marking the areas in questions
❑ 401 Water Quality Certification ❑ Isolated Wetland (_linear it or _acres)
❑ Riparian Buffer Authorization ❑ Minor Variance ❑ Major General Variance
® State Stormwater ❑ General ❑ SFR, ❑ SFR < 1 ac. ❑ Bkhd & Bt Rmp, ❑ Clear & Grub, ❑ Utility ❑ Other
❑ Low Density ❑ Low Density -Curb & Gutter _ # Curb Outlet Swales ❑ Off -site [SW (Provide permit #)]
® High Density -Detention Pond i # Treatment Systems ❑ High Density -Infiltration _ #Treatment Systems
❑ High Density -Bio-Retention _ # Treatment Systems ❑ High Density —SW Wetlands _ # Treatment Systems
❑ High Density -Other _ # Treatment Systems / ® MOD:® Major ❑ Minor ❑ Plan Revision ❑ Redev. Exclusion SW 8060530 (Frrovide penult #)
❑ Coastal Management ❑ Excavation & Fill ❑ Bridges & Culverts ❑ Structures Information
❑ Upland Development ❑ Marina Development ❑ Urban Waterfront
Quality ® Erosion and Sedimentation Control Plan with .1_10 acres to be disturbed. (CK # & Amt. (for DEO use))
I THREE — PLEASE CHECK ALL THAT IS APPLICABLE TO YOUR PROJECT (for both scoping and express meeting request)
Wetlands on Site ❑ Yes ® No
Wetlands Delineation has been completed: ® Yes ❑ No
US ACOE Approval of Delineation completed: ® Yes ❑ No
Received from US ACOE ❑ Yes ® No
For DE Q use
Fee SDlit for multiple vermits: (Check # )
Buffer Impacts: ® No ❑ YES: acre(s)
Isolated wetland on Properly ❑ Yes ® No
404 Application in Process w/ US ACOE: ❑ Yes ® No Permit
Amount
SUBMITTAL DATES
Fee
I SUBMITTAL DATES
Fee
CAMA
$ Variance (❑ Mal; ❑ Min)
-
S
SW (❑ HD, ❑ Li ❑ Gen)
$ 401:
S
LQS
$ Stream Deter,_
S
NCDEQ EXPRESS March 2016

UNC-WILMINGTON— HURST HAMILTO.N PARKINC LOTS
A'C'DEO Egress Reyuc.cl A'arrative
General Description
Located at the intersection of Hurst Drive and I lamilton Drive. the Ilurst Parking Lots project
will consist of hvo (2) surface parking lots providing it total of +/- 574 spaces to accommodate
visitors and students. The proposed lots are anticipated to contain one entrance ofT Hurst. one
exit onto Hamilton, and one two-way access to N. MacMillan Drive. The project will include the
addition of hike parking stalls. a bus shelter; along with it modification to an existing. adjacent
SCM (i.e. the Lot K pond).
The project is located within the Cape Pear River Basin. with stormwater runoff from the
proposed project draining to Burnt Mill Creek. According to the N.C. Division of Water (Quality
BasinWide Information Management System (RIMS), the waterway is classified as C; Sw" at
this location (Stream Index 4 18-74-63-21).
Please refer to the attached conceptual layout for more information and the location of the
proposed parking Tots.
Discussion o/'Proposer/Stormwaler Management
The proposed project will be high density and will require a major modification to the existing
State Stormwwater Management Permit (S`.>F'8 060530 —attached) in this area of the UNCW
campus. The addition of the surface parking lots will require an expansion to the existing SWS
060530 permit boundary. To better mimic the true drainage area to the Stormwater Control
Measure (SCM). the modified permit boundary will now include existing BIJA that has been
previously unaccounted for, meaning that the SCM will be designed to provide equal or better
treatment for the net increase in 13L A for this modified permit boundary. The existing Lot h
pond will be renovated / expanded to accommodate the proposed increase in impervious area. As
it result of the increase in 1.3UA and expansion of the existing SCM, the wet pond design will be
modified to meet the Minimum Design Criteria.
Discussion ol'Proposed Erosion Control
In advance of parking lot construction (i.e. site grading. installation of storm drainage.
construction of built upon area, etc.), UNCW is proposing to move forward with clearing and
grubbing of the project area as it separate project. To accomplish this work, an erosion control
plan will be submitted for review and approval in advance of construction drawings for the
parking lot. Erosion control on this site will consist of sediment basins, diversion ditches, slope
drains, silt fence, and silt fence outlets. Any inlets, either existing or proposed will be protected
with inlet protection along with other requirements necessary for compliance with an approved
erosion control permit (e.g. construction entrances, temporary and permanent seeding, etc.). The
proposed disturbed area is +/-9 ac.

d 1. i� McADaras
.0 .% g6
I � \
I t t is ��\ �iC�) 1' � i� \ s®. .�" f t� i;t� % / Q�✓
Et.
may`. '2} 0
ILLUSTRATIVE MASTER PLAN FOR: r
UNCW, PARKING LOT ��'��. °LY�7-2
r
I I I 1
WILMINGTON, NORTH CAROLINA

Hall, Christine
From: Stubbs, Rebecca <[e-mail]>
Sent: Thursday, November 09, 2017 4:26 PM
To: Hall, Christine
Cc: Perry, Daniel
Subject: [External] SW8 060530 Express Request - Updated Package
Attachments: 2017-11-09 UNW-17060 Request for SW Express Permit.pdf
CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
[e-mail].
Good Afternoon Christine,
Thank you for your time yesterday to discuss the scope of the Hurst Hamilton Parking Lot project. I have attached an
updated Express Request form and a revised narrative as requested for this project. If I can provide you with any
additional information to set the date for the Express Review, please let me know.
I hope you enjoy your Veteran's Day off!
Thanks,
Rebecca Stubbs, El I Designer II, Water Resources + Infrastructure r
McAdams`
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x224 I direct 919. 287. 0740 1 [e-mail]
www.mcadam'sco.com1 linkedin•I twitter I instazram I join our team
�=J MCADAMS
creating experiences through experience .
1

10
0
s
j
per...

Fo, HO Use ONLY
Reviewer.
North Caro I ina Department of Env iron menta I Quality sears )
Request for Express Permit Review `y �3qqqq
Time y (q lrrte
FILL-IN all the information below and CHECK the Permit(s) you are requesting for express review. Call and Email the completed form to the
Permit Coordinator along with a completed DETAILED narrative site plan (PDF file) and vicinity map (same items expected in the application
package oftheprojectlocation. Please include this form in the application package.
• Asheville Region -Alison Davidson 828.296-4698;alison.davidson(ddancdenr.gov
• Fayetteville or Raleigh Region -David Lee 919-791-4203;david.lee(ancdenr.gov
• Mooresville or Winston Salem -Marcia Allocco 704-235-2107; marcia.allocco(dncdenr.pov
• Washington Region -Lyn Hardison 252-948-3842orlvn.hardison(dpncdenr.gov
• Wilmington Region -Cameron Weaver 910-796-7303 or cameron.weaven@,ncdenr.gov
NOTE: Project application received after 12 noon will be stamped in the following work day.
Project Name: HURST PARKING LOTS County: NEW HANOVER
Applicant RACHELPATRICK Company:UNCW
Address: 601 S COLLEGE ROAD City. WILMINGTON. State: NC Zip: 28403
Phone: [phone], Fax:[phone], Email. ahp [e-mail]
Ph I L ti
SW 8980405
SW _
SWDE_
NPS _
NPDES_Q W
wo —_
E&S _
E&S _
Other
on:
S #_ JOBS
SECTION ONE: REQUESTING A SCOPING MEETING ONLY RECT OCT 2 4 20171
❑ Scoping Meeting ONLY ❑ DWR, ❑ DCM, ❑ DEMLR, ❑ OTHER:
SECTION TWO: CHECK ONLY THE PROGRAM (S)YOU ARE REQUESTING FOR EXPRESS PERMITTING
❑ 401 Unit ❑ Steam Origin Defarmrnaton _ # of steam calls — Please attach TOPO map marking the areas in questions
ElIntermil;EntlPerennial Determination: _ # of stream calls - Please attach TOPO map marking the areas in questions
❑ 401 Water Quality Certification ❑ Isolated Wetland (_linear ff'or _acres)
❑ Riparian Butler Authorization ❑ Minor Variance ❑ Major General Variance
® StateStormwaler ISW - Scoping Only ❑ SFR < 1 ac. ElBkhd & Bt Rmp, ElClear & Grub, El Utility ElOther
❑ Low Density ow ensi - ur utter _ ,Curb Outlet Swales ❑ OtFsito [SW _ (Provide perml #)]
® High Densily-Detention Pond 1 # Treatment Systems ❑ High Density -Infiltration _ #Treatment Systems
❑ High Density -Bio-Retention _ # Treatment Systems ❑ High Density -SW Wetlands _ It Treatment Systems
® High Density -Other _ It Treatment Systems /® MOD:❑ Major ® Minor ❑ Plan Revision ❑ Redev. Exclusion SW 8060530 (Provide permiu)
❑ Coastal Management ❑ Excavation & Fill ❑ Bridges & Culverts ❑ Structures Information
❑ Upland Development ❑ Marina Development ❑ Urban Waterfront
® Land Quality ® Erosion and Sedimentation Control Plan with .al_10 acres to be disturbed. (CK # & Am (for DEO use))
SECTION THREE - PLEASE CHECK ALL THAT IS APPLICABLE TO YOUR PROJECT (for both sopping and express meeting request)
Wetlands on Site ❑ Yes Z No Buffer Impact: ® No ❑ YES: —acre(s)
Wetlands Delineation has been completed: ® Yes ❑ No Isolated wetland on Property ❑ Yes ® No
US ACOE Approval of Delineation completed: ® Yes ❑ No 404 Application in Process wl US ACOE: ❑ Yes ® No Permit
Received from US ACOE ❑ Yes ® No
For I)FO use onh
Fee Solitfor multiole oermils:(Check# ) Total FeeAmountS
SUBMITTAL DATES
Fee
SUBMITTAL DATES
Fee
CAMA
s
Variance(❑ Maj;❑ Min)
5
SW (❑ HD, ❑ LD, O Gen)
s
401:
s
Los
S
Stream Deter
s
NCDEQ EXPRESS March 2016,�rt „�, ,� .�,^[ 1/ T l� �e-�h ` ' �"ec^ \h r ✓`'`��

ZINC-W'ILMINGTON —I I URST PARKING LOTS
NCDEQ Express Request Narrative
General Description
Located at the intersection of Hurst Drive and Hamilton Drive, the Hurst parking Lots project
will consist of two (2) surface parking lots providing a total of +/- 574 spaces to accommodate
visitors and students. The proposed lots are anticipated to contain one entrance off Hurst, one
exit onto Hamilton. and one two-way access to N. - MacMillan Drive. The project will include the
addition of bike parking stalls, a bus shelter, along with a modification to an existing, adjacent
BMP (i.e. the Lot K pond). In addition, and if feasible, the project scope includes a portion of the
Hurst / Hamilton Lot parking lot to be permeable pavement.
The project is located within the Cape Pear River Basin, with storruwater runoff from the
proposed project draining to Burnt Mill Creek. According to the N.C. Division of Water Quality
BasinNide Information Management System (BIMS), the waterway is classified as C; Sw" at
this location (Stream Index 9 18-74-63-2).
Please refer to the attached conceptual layout for more information and the location of the
proposed parking lots.
Discussion of Proposed Stormwater Management
The proposed project will be high density and will require a major modification to the existing
State Stormwater Management Permit (SW8 060530 — attached) in this area of the lNC\V
campus. The existing Lot K pond will be renovated / expanded to accommodate the proposed
increase in impervious area and the parking lots will also incorporate pervious pavement to the
extent possible. In addition, and in advance of submittal of formal design drawings / calculations;
attached is a hydrogeologic evaluation that has been prepared as pan of the documentation that is
required to relax the 24-inch separation between infiltration system and the seasonal high-water
table (SI-MIT).
Discussion of Proposed Erosion Control
In advance of parking lot construction (i.e. site grading, installation of storm drainage,
construction of built upon area, etc.), lNCW is proposing to move forward with clearing and
grubbing of the project area as a separate project. To accomplish this work, an erosion control
plan will be submitted for review and approval in advance of construction drawings for the
parking lot. Erosion control on this site will consist of sediment basins, diversion ditches, slope
drains, silt fence, and silt fence outlets. Any inlets, either existing or proposed will be protected
with inlet protection along with other requirements necessary for compliance with an approved
erosion control permit (e.g. construction entrances, temporary and permanent seeding, etc.). The
proposed disturbed area is +/-9 ac.

ECS SOUTHEAST, LLP Setting the Standard for Service
--=r. Geotechnical • Construction Materials - Environmental • Facilities
nG FeGrmcr, Gu,op•ss rrtm G-'0^
L;; Y?omsivrrxi @n�irrmn Fmm J"83
October 4, 2017
Mr. Brandon Finch
McAdams
2905 Meridian Parkway
Durham, North Carolina 27713
Reference: Report of Hydrogeologic Evaluation
Green Tract Parking - UNCW
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091 .
Dear Mr. Finch:
ECS Southeast, LLP (ECS) was requested to observe the seasonal high water table (SHWT)
and to perform infiltration testing at twenty locations within the stormwater control measure
(SCM) area(s) at the parcel located between Hamilton Drive and Hurst Drive on the UNCW
campus in Wilmington, New Hanover County, North Carolina (Figure 1). ECS was then
requested to provide a Hydrogeologic Evaluation of the site in accordance to the North Carolina
Department of Environmental Quality (NCDEQ) standard for relaxing the 24-inch separation
between infiltration systems and the SHWT. This letter, with attachments, is the report of our
evaluation.
Field Testing
On August 2V, 241", and 25`', 2017, ECS conducted an exploration of the subsurface soil and
groundwater conditions at twenty requested locations. These locations are shown on the
attached Boring Location Plan (Figure 2). ECS located the borings by using a site plan provided
by McAdams. The purpose of this exploration was to obtain subsurface information of the in -
situ soils for the SCM area(s). ECS explored the subsurface soil and groundwater conditions by
advancing one hand auger boring into the existing ground surface at each of the requested
boring locations. ECS visually classified the subsurface soils and obtained representative
samples of each soil type encountered. ECS also recorded the SHWT, based on visual
observation of penetrated soils, and groundwater elevation observed at the time of the hand
auger borings. The attached Infiltration Testing Form provides a summary of the subsurface
conditions encountered at the hand auger boring locations.
The SHWT and groundwater elevation was estimated at the boring locations below the existing
grade elevation. A summary of the findings are as follows:
Location
SHWT
Groundwater
1-1
6 inches
30 inches
1-2
6 inches
36 inches
1-3
6 inches
34 inches
1-4
6 inches
32 inches
1-5
8 inches
30 inches
1-6
10 inches
36 inches
1-7
6 inches
36 inches
1-8
20 inches
38 inches
ECS Capitol Seaices. PLLC • ECS Florida. LLC - ECS Md-AtianSc. LLC • ECS ivlid=Nest LLC • EGS Southeast, LLP • ECS texas, UP
w,wV.ecsll+ni ted.Con)

Report of Hydrogeologic Evaluation
Green Tract Parking - UNCW
Wilmington, New Hanover County, North Carolina
ECS Project No. 49,5091
October 4, 2017
1-9
22 inches
36 inches
1-10
6 inches
32 inches
1-11
14 inches
Winches
1-12
6 inches
24 inches
1-13
6 inches
30 inches
1-14
15 inches
32 inches
1-15
20 inches
36 inches
1-16
18 inches
48 inches
1-17
16 inches
36 inches
1-18
18 inches
32 inches
1-19
18 inches
32 inches
1-20
16 inches
30 inches
ECS has conducted twenty infiltration tests utilizing a compact constant head permeameter near
the hand auger borings in order to estimate the infiltration rate for the subsurface soils.
Infiltration tests are typically conducted at two feet above the SHWT or in the most restrictive
soil horizon. Tests in clayey conditions are conducted for durations of up to 30 minutes. If a
more precise hydraulic conductivity value is desired for these locations; then ECS recommends
collecting samples by advancing Shelby tubes and performing laboratory permeability testing.
Field Test Results
Below is a summary of the infiltration test results:
Location
Description
Depth
Inches/
hour
1-1
Black silty SAND
10 inches
0.20
1-2
Black silty SAND
10 inches
0.47
1-3
Black silty SAND w/ clay lens
10 inches
0,067
1-4
Black silty SAND
10 inches
0.10
1-5
Black silty SAND
10 inches
0.11
1-6
Black/gray silty SAND
10 inches
0.22
1-7
Black silty SAND
10 inches
0,042
1-8
Gray silty SAND w/ sand lens
10 inches
0.25
1-9
Gray fine SAND w/ silt
10 inches
2.82
1-10
Black silty SAND
10 inches
0.09
1-11
Black/gray silty SAND
10 inches
0.11
1-12
Black silty SAND
10 inches
0.081
1-13
Black silty SAND
10 inches
0.12
1-14
Brown/gray silty SAND
10 inches
0.17
1-15
Black/brown silty SAND
10 inches
0.63
1-16
Gray silty SAND
10 inches
0.061
1-17
Black silty SAND w/ clay
10 inches
0.042
1-18
Gray silty SAND
10 inches
0.20
1-19
Gray silty SAND
10 inches
0.26

Report of Hydrogeologic Evaluation
Green Tract Parking - UNCW
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
October 4, 2017
-20 1 Gray silty SAND 1 10 inches 1 0.22
Infiltration rates and SHWT may vary within the proposed site due to changes in elevation and
subsurface conditions.
Hydrogeologic Evaluation
There are required components listed in the NCDEQ Stormwater Design Manual in order to
reduce the 24-inch separation between infiltration systems and the SHWT. In order to evaluate
thehydrogeologic conditions of an area designated for an infiltration SCM, these components
are evaluated. Below are the required component descriptions for this site.
• The site is located in the Coastal Plain Physiographic Province. The Coastal Plain is
composed of seven terraces, each representing a former level of the Atlantic Ocean.
Soils in this area generally consist of sedimentary materials transported from other areas
by the ocean and rivers. These deposits vary in thickness from a thin veneer along the
western edge of the region to more than 2,000 feet near the coast. The sedimentary
deposits of the Coastal Plain were deposited upon consolidated rocks similar to those
underlying the Piedmont and Mountain Physiographic Provinces. The groundwater flow
direction is believed to be to the east towards Bradley Creek and the Atlantic Ocean.
• The majority of the site was observed to be relatively flat having approximately the same
elevation across the site. The site is bordered by Hamilton Drive, Hurst Drive, and
MacMillan Ave. The site has a stormwater treatment SCM for the apartment complex to
the northwest of the site. No abandoned wells or rock outcrops were observed.
• Based on regional geology and observations made in previous geotechnical borings (B-
6) advanced by ECS in July of 2005 (see attached boring logs), the site consists of
surficial deposits of sandy sediment with silt up to 35 feet in depth. No rock or confining
layer was observed up to 40 feet. The marine Pee Dee Formation, which is generally
comprised of sand, clayey sand, and clay that was deposited during the Cretaceous,
then underlies the surficial sediment at depths greater than 40 feet.
• The hydraulic conductivity of the surficial sediment was tested and resulted in a range
from 0.081 to 2.82 inches per hour at the test locations. Transmissivity, which is equal
to hydraulic conductivity multiplied by saturated aquifer thickness, was calculated using
the low and high conductivity values from this site and saturated aquifer thickness
(approximately 44 feet) was calculated based on the depth to a consolidated geologic
layer encountered while drilling nearby geotechnical boring B-6 (47 feet) and depth to
groundwater measurements from the site (approximately 3 feet below ground surface).
Based on the range of hydraulic conductivity values measured at the site, the range of
transmissivity values was determined to be between 42.8and 1,489.0 inches squared
per hour, respectively.
3

Report of Hydrogeologic Evaluation
Green Tract Parking - UNCW
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
October 4, 2017
• The SHWT was observed to range from 6 to 22 inches below the existing grade
elevation at the locations tested.
• The surficial aquifer of the site consists of silty/sandy conditions where groundwater
flows without confining conditions. The site currently consists of two stand-alone
structures with a parking lot and landscaped areas. Stormwater is currently being
treated by an onsite infiltration system and a swale system. A proposed infiltration SCM
(pervious pavement) is to be constructed in order to contain and treat the runoff of the
anticipated impervious areas.
• Recharge to the shallow, unconfined aquifer consists of surface infiltration of
precipitation and irrigation of the vegetated portions of the site. The groundwater
receptors in the area consist of stormwater ponds located to the north and east of the
site. The groundwater discharge feature is Bradley Creek. The topography of the area
is relatively flat and the subsurface flow media consists of silty sands and sands with silt
which results in minimal surface water movement in the swales with most surface water
removal by infiltration. The replacement of the impermeable parking areas with pervious
pavement will reduce the surface runoff into the swales while allowing more area of the
site to absorb the surface water via infiltration. The pre and post flow calculations for the
site were generated by McAdams and are included in the attachments.
• A mounding analysis was generated utilizing the United States Geological Survey
(USGS) spread sheet solving the Hantush (1967) equation for groundwater mounding
beneath an infiltration basin. The data used for calculating the mounding conditions
were collected from site specific field data, design data, and soil characteristics. On the
chart, (R) represents a one inch storm event over a 12 hour period. Specific yield (Sy)
was estimated by referencing the USGS Compilation of Specific Yield for Various
Materials by A.I. Johnson, 1963. Hydraulic conductivity (K) was determined in the field
and is referenced in the text above. Basin dimensions (X and Y) were provided by
McAdams (the site civil designer). There will be several sections of pervious pavement
to be constructed, ECS chose the largest pervious section for this calculation. Time (T)
is the 3 day period set forth by NCDEQ for an infiltration basin to function. Thickness of
saturated zone HI(0) was derived by subtracting the depth to the less permeable
underlying consolidated layer (approximately 47 feet) from the depth to groundwater (3
feet). This calculation uses the median hydraulic conductivity represented by the tests
that were conducted. The spreadsheet is included with the attachments.
4

Report of Hydrogeologic Evaluation
Green Tract Parking - UNCW
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
October 4, 2017
Closure
ECS's analysis of the site has been based on our understanding of the site, the project
information provided to us, and the data obtained during our exploration. If the project
information provided to us is changed; please contact us so that our recommendations can be
reviewed and appropriate revisions provided, if necessary. The discovery of any site or.
subsurface conditions during construction which deviate from the data outlined in this
exploration should be reported to us for our review, analysis and revision of our
recommendations, if necessary. The assessment of site environmental conditions for the
presence of pollutants in the soil and groundwater of the site is beyond the scope of this
geotechnical exploration.
ECS appreciates the opportunity to provide our services to you on this project. If you have any
questions concerning this report or this project, please contact us at [phone].
Respectfully,
ECS SOUTHEAST, LLP
a
K. Brooks Wall
Project Manager
bwall(abecslimited.com
910-686-9114
Attachments:
Figure 1 — Boring Location Plan
Infiltration Testing Form
Geotechnical Boring Logs
USGS Mounding Spreadsheet
ASFE Document
M ;�
Michael L. Maloy, C.P.G.
Principal Geologist
mmaloy(a)ecslimited. com
540-785-6100

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® APPROXIMATE BORING LOCATIONS
SCALE SHOWN ABOVE
Green Tract Parking Lot, UNCW.
Wilmington,
New Hanover County, North Carolina
ECS Project # 49.5091
August 23, 24, 25, 2017
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Figure 2— Boring Location Plan
Provided by: Google Earth

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 24th 25th 2017
Location Depth USCS Soil Description
1-1 0-30" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 30 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.20 inches per hour
Location Depth USCS Soil Description
1-2 0-24" SM Black silty SAND
24"-48" SW Gray fine SAND w/ silt
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.47 inches per hour
Location Depth USCS Soil Description
1-3 0-36" SM Black silty SAND w/ clay lens
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 34 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.067 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 24tn 251n 2017
Location Depth USCS Soil Description
1-4 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.10 inches per hour
Location Depth USCS Soil Description
1-5 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 8 inches below the
existing grade elevation.
Groundwater was encountered at 30 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.11 inches per hour
Location Depth USCS Soil Description
1-6 0-18" SM Black/gray silty SAND
18"-36" SW Gray fine SAND w/ silt
Seasonal High Water Table was estimated to be at 10 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.22 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 24th 25th 2017
Location Depth USCS Soil Description
1-7 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.042 inches per hour
Location Depth USCS Soil Description
1-8 0-20" SW Gray silty SAND w/ sand lens
20-48" SM Black silty SAND
Seasonal High Water Table was estimated to be at 20 inches below the
existing grade elevation.
Groundwater was encountered at 38 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.25 inches per hour
Location Depth USCS Soil Description
1-9 0-14" SW Gray fine SAND w/ silt
14-36" Sc Tan fine SAND w/clay
Seasonal High Water Table was estimated to be at 22 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 2.82 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 24th 25th 2017
Location Depth USCS Soil Description
1-10 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.09 inches per hour
Location Depth USCS Soil Description
1-11 0-40" SM Black/gray silty SAND
Seasonal High Water Table was estimated to be at 14 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.11 inches per hour
Location Depth USCS Soil Description
1-12 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.081 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 24th 25tn 2017
Location Depth USCS Soil Description
1-13 0-36" SM Black silty SAND
Seasonal High Water Table was estimated to be at 6 inches below the
existing grade elevation.
Groundwater was encountered at 30 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.12 inches per hour
Location Depth USCS Soil Description
1-14 0-36" SM Brown/gray silty SAND
Seasonal High Water Table was estimated to be at 15 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.17 inches per hour
Location Depth USCS Soil Description
1-15 0-36" SM Black/brown silty SAND
Seasonal High Water Table was estimated to be at 20 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.63 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23rd 241n 251n 2017
Location Depth USCS
1-16 0-24" SM
24-48" Sc
Soil Description
Gray silty SAND
Tan/orange clayey SAND
Seasonal High Water Table was estimated to be at 18 inches below the
existing grade elevation.
Groundwater was encountered at 48 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.061 inches per hour
Location Depth USCS Soil Description
1-17 0-36" SM Black silty SAND w/ clay
Seasonal High Water Table was estimated to be at 16 inches below the
existing grade elevation.
Groundwater was encountered at 36 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.042 inches per hour
Location Depth USCS Soil Description
1-18 0-101, SM Gray silty SAND
10-36" Sc Black silty SAND
Seasonal High Water Table was estimated to be at 18 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.20 inches per hour

Infiltration Testing Form
Green Tract Parking
Wilmington, New Hanover County, North Carolina
ECS Project No. 49.5091
August 23`d 24th 251h, 2017
Location Depth USCS Soil Description
1-19 0-36" SM Gray silty SAND
Seasonal High Water Table was estimated to be at 18 inches below the
existing grade elevation.
Groundwater was encountered at 32 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.26 inches per hour
Location Depth USCS Soil Description
1-20 0-36" SM Gray silty SAND
Seasonal High Water Table was estimated to be at 16 inches below the
existing grade elevation.
Groundwater was encountered at 30 inches below the existing grade
elevation.
Test was conducted at 10 inches below existing grade elevation
Infiltration Rate: 0.22 inches per hour

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This smeadsheet will calculate the neignt of a"ounel mound beneath a stmmwrime infilvation basin. More Infar-ration can be for In the Us. Geological Survey
Scientific Inver:igavons Reoort 20'.0 5102 "Slnclation of gonsarr :e: numi g berm momment.1 Izi,e nwate: in.iltra:ian oasi.,".
71cuser m tsnecdy inpltrule,role (R), specific vie Io(Sy), F.Fmnta l bvorau I,r ror lvl tY(Khl losm.croensicns(x,y), d u racoon of all It: atop one.(1), and the Initial
tnickness of toe saturated zone (ai(0), neigh: of :he ware: table if tee bottom of the aquifer is me datum). For a scuare oasis ^re half widen edust, the half lengtn (v = y). For a
rectangular basic, if the use: wane, the wale::aole change, ace: nehcmlar to toe long side, sdeci`.y r as me soon dimension ane y as toe long dimension. conversely, If :he
Lserwatts the values perpendicular to:.hesinct sic or seedily y as the ste-t cincensor,r, as the org dim ensior. A l l distances a to from the center of the dasim. users can
change the distances from the center of the basin a: wFic r water :able aquifer thickness are calculated
Cells In in yellow are values tnat cars he. Inanged by the usercells nighllgmed'mred are output values based be user-sheof ed inputsthe user MUS121ick the blue
el e-Calmlate Now' butmp each time ANY of the user -specified inputs an! changedothervdse.necess,ey ite: cidns to cone gd oo the correct solution will at no cache aoc
values shown will be Incorrect. Use cohsis:en:urisf0r all Inner values (for example, fee: ane days)
In but values
A
R
Sy
K
x
y
t
blip)
llllllllllll4_St563J h ream)
171— Ah(max)
Ground. Distance from
water center of basin
Mounding, in in xdindramr, in
feet feet
a
20
40
50
60
70
80
90
100
Disclaimer
cse eoais:en; ur.its (e.p,. (detR Gays or lnchesR hnms) Comenion Table
im/hpur feet/day
Recharge (infiltration) rate (feet/day) 0.67 1.33
Specific yield, Sy (dimensionless, between 0 and 1)
H o ran nta l all AD l is eo ad uetivity, Kh (fad/day)` 7.00 4,00 in he noon aternsuoy,, thissprcam,er,
1/2 length of basin is, direction, in feet) (USGS se 7010 5102), vertical soil permeability
1/2 width of basin(y direction, in feet) hours days ford), red,ded to tedpomptn nmhdnIal
duration of infiltration period (days) 36 150 nydr,uIh, ndoamdy(t/cl.
Initial thickness of saturated zone (feet)
maximum thickness of saturated zone (beneath center of basin at end of infiltration'peric d)
maximum groundwater mounding (beneath center of basin at end of infiltration period)
®Re -Calculate Now
I
I
I
Groundwater Mounding, in feet
t.goo
1.600
1,700
1,700
i
: 000
o.zao
.400
0.200
0 20 40 so eo 100 120 :40
This spreadsheet solving the Hantush (1967) equation for ground -water mounding beneath an infiltration basin
is made available to the general public as a convenience for those wishing to replicate values documented in
the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater
infiltration basins" or to calculate values based on user -specified site conditions. Any changes made to the
spreadsheet (other than values identified as user -specified) after transmission from the USGS could have
unintended, undesirable consequences. These consequences could include, but may not be limited to:
erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results
presented in the accompanying USGS published report. The USGS assumes no responsibility for the
consequences of any changes matle to the spreadsheet. If changes are made to the spreadsheet, the user is
responsible for documenting the changes and justifying the results and conclusions.

Geolechnical Engineering Report
Geotechnical Services Are Performed for
Specific Purposes, Persons, and Projects
Geotechnical engineers structure their services to an, the specific needs of
Cneir clients, A geoiechnical engineering study conducted for a civil engineer
may not fulfill the needs of a construction contractor or even another civil
engineer. Because each geotechnical engineering study is unique, each geo-
technical engineering report is unique, prepared solelylor the client No one
except you should rely on your geotechnical engineering report without first
conferring with the geofechnlcal engineer who prepared it And no one - not
even you -should apply the report for any purpose or project except the one
originally contemplated.
Read the Full Report
Serious problems have occurred because those relying on a geotechnical
engineering report did not read it all. Do not rely on an executive summary.
Do not read selected elements only.
A Geotechnical Engineering Report Is Based on
A Unique Set of Project -Specific factors
Geoiechnical engineers consider a numher of unique, project -specific factors
when establishing the scope of a study. Typical lactors include: the client's
goals, objectives, and risk management preferences. the general nature of the
structure involved, its size, and configuration; the location of the structure
on the site; acid other planned or existing site improvements, such as access
roads, parking lots, and underground utilities. Unless the geotechnical engi-
neer who conducted the study specifically indicates othervdise, do not rely on
a oeoiechnical engineering report that was:
• not prepared for you,
• not prepared for your project,
• not prepared for the specific site explored, or
• completed before important project changes were made.
Typical chances that can erode the reliability of an existing geotechnical
engineering report Include those that affect:
• the function of the proposed structure, as when it changed from a
parking garage to an office building, or from alight industrial plant
to a refrigeraied warehouse,
• elevation, comicuratlon, location, orientation, or welgni of the
proposed structure,
• composition of the design team, or
• project ownership.
As a general rule, aPways inform your geotechnical enoineer of project
changes - even minor ones - and request an assessment of their impact.
rieotechnical engineers cannot accent responsibility or liability mrproblems
that occur because their reports do not consider developments of which they
were not informed.
Subsurface Conditions Can Change
A geotechnical engineering report is based on conditions that existed at the
time the study was performed. Do not rely on a geotechnical engineering
report whose adequacy may have beer, affected by: the passage of time. by
man-made events, such as construction on or adjacent to the site, or by natu-
ral events, such as floods, earhqua:xes, or groundwater fluctuations. Always
contact the geotechnical engineer before applying the report to determine if it
is still reliable. Aminor amount of additional testing or analysis could prevent
major problems.
Most Geotechnical Findings Are Professional
Opinions
Site exploration identifies subsurface conditions only at those points where
subsurface tests are conducted or samples are taken. Geoiechnical engineers
review field and laboratory data and then apply their professional judgment
to render an opinion about subsurface conditions throughout the site. Actual
subsurface conditions may diner -sometimes significantly from those indi-
cated in your report. Retaining the geotechnical emineerwho developed your
report to provide construction observation is the most effective method of
managing the risks associated with unanticipated conditions.
A Report's Recommendations Are Not Final
Do not ove«ely on the construction recommendations included in your re-
port Those recommendations are not final, because oeoiechnical engineers
development principally from judomeni and opinion. Geotechnical engineers
can finalize their recommendations only by observing actual

subsurface conditions revealed during construction. The geotechnical eilm-
neer who developed your report cannot assume responsibility or liability for
the reports recommendations ii that engineer does not perbm construction
observaton.
A Geotechnical Engineering Report Is Subject to
Misinterpretation
Other design team members' misinterpretation of geotechnical engineer -
no reports has resulted in cosily problems. Lower Ghat risk by having your
geoiecbrrical engineer corder with appropriate me moats of the desla_rl ieam
after subm'Itino the report. Also retain your geotechnical engineer to review
peninegi elements of the design team's plans and specifications. Contractors
can also misinterpret a geotechnical engineering report. Reduce that risk by
having your geoiechnical engineer participate in piebid and preconsimcdoo
conferences, and by providing construction observation.
Do Not Redraw the Engineer's logs
Geotechnical engineers prepare final boring and testing logs based upon
their interpretation of field logs and laboraioiy data. To prevent errors or
omissions, the loos included in a geotechnical engineering report should
never be redrawn lot inclusion in architectural or other desian drawings.
Only photographic of electronic feproducoon Is acceptable, not recognize
that separating logs from the report can elevate risk.
Give Contractors a Complete Report and
Guidance
Some owners arid design professionals mistakenly believe they can make
contractors liable for un incipated subsurface conditions by limiting_ what
they provide for old preparation. To help prevent costly problems, give con-
Gaciors isle complete geoiechnical engineering report, but preface It with a
clearly written letter oftrausmittal. In that letter, advise contractors that the
sport was not prepared lot purposes of bid development and that the fepod's
accuracy is limited, encourage them to confer vf1m the geotechnical engineer
who prepared the report (a modest lee may be required) and/or to conductad-
dltlonal study to obtain the specific Types of otormation they need or prefer.
A pre'oid conference can also be valuable. Be sure contractors haveso'icient
timelio oerlorm additional study Only then might you be in a position to give
contractors the best information available to you, while requiring item to at
least share some of the financial responsibilities stemming from unantici-
pated conditions
Read Responsibility Provisions Closely
Some clients, design professionals, and contractors do not recognize that
geotechnical engineering is far less exact than other engineering disciplines,
This lack of understanding has created unrealistic expectations that have led
to disappointments, claims, and disputes. To help reduce the risk of such
outcomes, aeotechnical engineers commonly include a varieiyol explanatory
provisions In their reports. Sometimes labeled "hr itatmgs" many of tress
provisions indicate where geoiechnical engineers' responsibilities begin
and end, to help others recognize their own responsibilities and risks. Read
these orovisions closely. As:< questions. Your geotechnical engineer should
respond lullyand irankly.
Geoenvironmental Concerns Are Not Covered
The equipment, techniques, and personnel used to periorm a geoeniriron-
mental study diner significantly from those used to perform a geotechnical
study. For that reason, a aeoiechgical engineering report does not usually re-
late any geommonmental findings, conclusions, or recommendations. e.g ,
about the likelihood of encountering underground stofaae tanks or feaulaied
contaminants. Unanticipated environmental problems have led to numerous
project failures. If you have not yet obtained your own geoenvironmental in-
formation, ask your geoiechnical consultant for risk management guidance.
Do not rely on an environmental report prepared for someone else.
Obtain Professional Assistance To Deal with Mold
Diverse strategies can be applied during building design, construction, op-
eration, and on, to prevent significant amounts of mold from orow-
ing on indoorsurfaces. To be effective, all such siraieaies should be devised
for the express purpose of on, prevention, integrated into a comprehensive
plan, and executed with diligent oversight by a processional mold prevention
consultant. Because just a small amount of water or moisture can lead b
the development of severe mold infestations, a number of an, prevention
strategies locus on keel building surfaces dry. While groundwraier, wa-
fer infiltration, and similar issues may have been addressed as part of the
geoiechnical engineering study whose findings are conveyed in-mis report,
the geotechnical engineer in charge of this project is not a mold prevention
consultant. none of the services performed in connection with
the geotechnical engineer's study were designed or conducted
for the purpose of mold prevention. Proper implementation of
the recommendations conveyed in this report will not of itself
he sufficient to prevent mold from growing in or on the struc-
ture involved.
Rely on Your ASFE-Member Geotechnical
Engineer For Additional Assistance
Membership in ASFE/The Best People on Earth exposes geoiechnical engi-
neers to a wide array of risk management techniques that can be of Genuine
benefit for everyone involved with a constmctlon project. Comer With your
ASFE-member geotechnical engineer for more information.
ASFE
Ins Best Pe.Yle on E. IA
8811 Colesville Road/Suite G106, Silver Spring, MD 20910
Telephone:'301/565-2733 Facsimile:301/589-2017
e-mail: [e-mail] wvvw.asie.org
Copyright 2004 byASFE, Inc. Duplication, reproduction, or copying of this document, in whole or in part, by any means whalsoever, is strictly prohibited, except with ASFES specific
written permission. Excerpting, quoting, or otherwise exhacling voicing from this document is permitted only with the express Ivritten permission of ASFE, and only for purposes
of scholarly research or book review Only members of ASFE may use this document as a complement to or as an element cis geotechnical engineering report. Any other firm,
individual, or proof entitythat so uses this document without being anASFEmember could be committing negligent or intentional (fraudulent) misrepresentation.
IIGER06045.OM

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1. USGS; 7.5 MINUTE, QUAD, "WILMINGTON', NORTH CAROLINA, 2016 NATIONAL GEOGRAPHIC SOCIETY
2. LAT 34.221610 N, LONG:-77.881085 W
0 1,000 2,000
ENVIRONME NTAL ASSESSMENT ®Feet
Tj
UNCW - PARKING LOT IMPROVEMENTS 1 inch = 2,000 feet
PHASE 2 PARKING LOTS 2A213 DATE: 8/2812017
McADAMS FIGURE 1. USGS TOPOGRAPHIC VICINITY MAP JOB NO: UNW-17060
WILMINGTON, NEW HANOVER COUNTY, NORTH CAROLINA DRAWN BY buchholz
X'.\Prolects\UNW\UNW-17060\Storm\Wetlantls\GIS\UNW17060_Figure 1 USGS.mxa, 8/28/201710:01'.16AM, buchholz

FIGURE 4CONCEPTUAL SITE PLAN
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NOTES'
1. USDA-SCS', SOIL SURVEY OF NEW HANOVER COUNTY, NORTH CAROLINA', SHEET 19
2. LAT. 34.221610 N, LONG:-77.881085 W
0 500 1,000
ENVIRONMENTAL ASSESSMENT Feet
UNCW - PARKING LOT IMPROVEMENTS 1 inch= 1,000feet
PHASE 2 PARKING LOTS 2A2B DATE 8/28/2017
WADAMS FIGURE 2. NRCS SOIL SURVEY JOB NO: UNW-17060
WILMINGTON, NEW HANOVER COUNTY, NORTH CAROLINA DRAWN BY: buchhclz
X'.\Pmlects\UNVV\UNW-17060\Storm\Wetlanrls\GIS\UN W17060_Figure 2 Soils Map. mxd, 5128/2017 9;58'.07 AM, buchholz

Yates, Kevin
From: Capita, Rachel A CIV USARMY CESAW (US) <[e-mail]>
Sent: Wednesday, October 04, 2017 8:12 AM
To: Yates, Kevin
Subject: RE: UNCW Parking lot improvements- site visit
Hi Kevin,
Sorry for they delayed response. Yes we were able to visit the site and verify your delineation. At this time the applicatior
Unfortunately I have received multiple nationwide permits in the last couple of weeks that take priority over PJD and AJD
out as soon as possible.
Thanks,
Rachel
-----Original Message -----
From: Yates, Kevin [mailto:[e-mail])
Sent: Tuesday, October 3, 2017 10:40 AM
To: Capita, Rachel A CIV USARMY CESAW (US)<[e-mail]>
Subject: [EXTERNAL] RE: UNCW Parking lot improvements -site visit
Hey Rachel,
Was wondering if you had a chance to go by this site at UNCW?
Thanks,
Kevin
Kevin Yates I Senior Environmental Consultant, Water Resources
McAdams
2905 Meridian Parkway, Durham, NC 27713 office 919. 361. 5000 x271 I direct 919. 287. 0895 1 mobile [phone]
Blockedwww.mcadamsco.com I linkedin I twitter I instagram I join our team
creating experiences through experience
-----Original Message -----
From: Capita, Rachel A CIV USARMY CESAW (US)(mailto:[e-mail])
Sent: Tuesday, September 19, 2017 4:37 PM
To: Yates, Kevin <[e-mail]>
Subject: RE: UNCW Parking lot improvements- site visit
That's alright. I will have to check my calendar about next week, but it would most likely be in October. You do not need t
check it out tomorrow as I have scheduled a couple of other appointments in the area. Just let me know if you would rath
Thanks,
Rachel
-----Original Message ----
From: Yates, Kevin [mailto:[e-mail])
Sent: Tuesday, September 19, 2017 4:33 PM
To: Capita, Rachel A CIV USARMY CESAW (US)<[e-mail]>
G ihiort fFYTFPAIAI I PP I IAIrAA/ Par imo Ini imnrnvo manic-6ft visit

I would like to set up a time to meet onsite to verify your A1D request for the UNCW parking lot improvement project. An
Wednesday September 20th around 1PM? Please let me know if this date and time will work for you and if not we will fin
Thanks,
Rachel
Rachel Capito
Regulatory Specialist
U.S. Army Corps of Engineers
Wilmington District
Office: 910.251.4487
Cell: 910.899.6051

Weaver, Cameron
From: Finch, Brandon <[e-mail]>
Sent: Friday, October 20, 2017 4:43 PM
To: Weaver, Cameron
Cc: Riggins, Daryl; Jamison, Galen
Subject: [External] UNCW Hurst Lots - Erosion Control Express & Stormwater Scoping Meeting
Request
Attachments: 2017-10-20 UNW-17060 Request for Express Permit & SW Scoping Meeting.pdf;
UNW17060_Figure 1 USGS.pdf; UNW17060_Figure 2 Soils Map.pdf; UNW17060_Figure
3 Existing Conditions.pdf; UNW17060 Figure 4 - Conceptual Site Plan.pdf; 2017-10-04
USACE - Rachel Capito email .pdf
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you verify that the
attachment and content are safe. Send all suspicious email as an attachment to [e-mail].
Good afternoon Cameron,
Thank you for taking my call earlier today.
Please find attached our express request for this project, along with supporting documentation. As discussed, we would
.like for the meeting to be an express review for erosion control (clearing & grubbing only) and the stormwater portion to
be Scoping only.
Please let me know if you have any questions or need any additional information.
As always, thank you for your help!
Brandon Finch j Director, Institutional
McAdams
2905 Meridian Parkway, Durham, NC 27713
office 919. 361. 5000 x127'[ direct 919. 287. 0892 1 mobile [phone] finch(n)mcadamsco.com
www.mcadamsco.com [ linkedin [ twitter [ instaaram [ join our team
1111
creating experiences through experience