SW8060238_HISTORICAL FILE_20171010

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8 N 0 Vs
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
m HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
20 k-1 W K)
YYYYMMDD

ROY COOPER
G,,m nor
MICHAEL S. REGAN
Secretary
Energy. Mineral &
Land Resources
ENVIRONMENTAL QUALITY
October 10. 2017
Maco Road Partners, LLC
Andrew Sandman, Member / Manager
7101 Creedmoor Road, Suite 122
Raleigh, NC 27613
Subject: State Stormw•ater Management Permit No. SW8 060238 Alod &-
Notice of Tile Review
Grayson Park Phase 1
High Density Subdivision R'et Detention Pond Project
Brunswick County
Dear Mr. Sandman:
TRACY DAVIS
Director
The Wilmington Regional Office received a complete, modified State Stonnwater Management Permit
Application for Grayson Park Phase 1 on August 3, 2017 with additional information on October 5,
2017. Staff review of the plans and specifications has determined that the project, as proposed; will
comply with the Stormwater Regulations set forth in Title 15A NCAC 21-1.1000 and Session Law 2008-
211. We are forwarding modified Permit No. SN8 060238 dated October 10, 2017, for the construction,
operation and maintenance of the BMP's and built -upon area associated with the subject project.
This permit shall be effective from the date of issuance until September 21. 2020 and shall be subject to
the conditions and limitations as specified therein. Please pay special attention to the conditions listed in
this permit regarding the. Operation and N4aintenance of the BNIP(s), recordation of deed restrictions,
certification of the BMP's, procedures for changing ownership, transferring the permit, and renewing the
permit. Failure to establish an adequate system for operation and maintenance of the stormwater
management system, to record deed restrictions, to certify the BMP's, to transfer the permit, or to renew
the permit, will result in future compliance problems.
The following modifications are included and covered by this permit:
The total number of lots in Phase 1 C. Section 3 (Pond' 7 drainage area) will remain at 36, but the lot lines
are slightly modified on the revised plans. The allocation of built -upon area (BUA) for these 36 lots is
increasing from 3,000 square feet to 4,000 square feet per lot. Pond 47 sizing calculations show that the
existing pond design will accommodate the increased BUA without revisions to the pond.
Upon file review, it was discovered that we have not received any engineer certification(s) for the
stormwater system(s), and that we have not received any recorded deed restrictions for the subdivision.
Please note that these are requirements of the permit. To begin to bring this project into compliance, a
plan of action must be received within 30 days. Please reference the attached non -compliant Notice of
Inspection.
Failure to provide the requested information, or to respond to this letter \vilh a plan of action, including a
timeline to resolve the identified deficiencies. by November 11. 2017, are considered violations of the
permit. If the requested information is not submitted to this office by the due date, then DEMLK staff
may re -inspect the site and issue a Notice of Violation. Please also note that any individual or entity found
to be in noncompliance with the provisions of a stormwater management permit or the stormwater rules is
subject to enforcement action as set forth in NCGS 143 Article 21, including the assessment of civil
penalties of up to $25,000 per day.
State of Non It Carolina 1 Em9romnrnial Quality I Energy. Mineral and Land Rrsources
Wilmington Regional Office 1127 Cardinal Drive Esto,sion I Wilmington, NC 29405
910 7%R1$

State Stormwater PermitNo. SNS 060238
Page 2 r1- 2 '
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 OAH 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 wx�v.NCOAH.com. Unless such demands are made this permit shall be final and binding
If you have any questions; or need additional information, please contact Steve Pusey in the Wilmington
Regional Office, at [phone].
Sincerely.
(,Tracy Davis,, P.E., Director
Division of Energy, Mineral and Land Resources
GDS/sgp: A\\StormwaterAPermits & Projects\2006\060233 IID\2017 10 permit 060238
Enclosures:
• Engineer Certification form
• Permit application
• Supplements
• Deed Restriction form
• Inspection report
cc: Elizabeth M. Nelson, PE — Cape Fear Engineering
Brunswick County Inspections
Brunswick County Engineering
Wilmington Regional Office Stormwater File
StatcoMonliCarolina I Em•imnmental Quality I Encrgy.Mincizland Land Rcsnurces
Wilmington Regional O$ice I I27Caidinal Drive Extension I Wilinington,NC 28405
910 796 7215

State Stormwater Management Systems
Permit No. SW8 060238
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF ENERGY, MINERAL AND LAND RESOURCES
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY SUBDIVISION DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of
North Carolina as amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
Maco Road Partners, LLC
Grayson Park Phase 1
Grayson Parkway, Leland, Brunswick County
FOR THE
construction, operation and maintenance of five (5) wet detention ponds in compliance
with the provisions of 15A NCAC 2H .1000, effective September 1, 1995 (Ponds 4, 5,
and 6) and October 1, 2008 (Pond 7 and a portion of Pond 1, see Section 1.5), hereafter
referred to as the "stormwater rules" and the approved stormwater management plans
and specifications and other supporting data as attached and on file with and approved
by the Division of Energy, Mineral and Land Resources and considered a part of this
permit.
This permit shall be effective from the date of issuance until September 21, 2020 and
shall be subject to the following specified conditions and limitations:
I. DESIGN STANDARDS
This permit is effective only with respect to the nature and volume of stormwater
described in the application and other supporting data.
This stormwater system has been approved for the management of stormwater
runoff as described in Section 1.5 on of this permit. The subdivision is permitted
for the following built -upon area: (Phase 1A) Lots 1 through 59, each allowed
3,500 square feet; (Phase 1 B) Lots 58 through 95, each allowed 3,000 square
feet, (Phase 1 C Sections 1 & 2) Lots 1 through 52 and Lots 87-88, each allowed
3,000 square feet, and (Phase 1C Section 3) Lots 53 through 86 and Lots 89-90,
each allowed 4,000 square feet, and (Phase 1A/1 B multifamily) 60 units each
allowed 2,160 square feet.
3. The runoff from all built -upon area within the permitted drainage areas of this
project must be directed into the permitted stormwater control system.
4. The tract will be limited to a maximum of 1,368,756 square feet of built -upon
area. The wet ponds designated as pond #1, #4, #5, #6, and #7 have been
designed to treat the runoff from 465,462; 221,407; 334,310; 152,842 and
194,735 square feet of Built -Upon Area, respectively.
Page 3 of 10

State Stormwater Management Systems
Permit No. SW8 060238
5. The following design elements have been permitted for this wet detention pond
stormwater facility, and must be provided in the system at all times.
Design Criteria
Pond #1
Pond #4
Pond #5
Pond #6
Pond #7
a. Drainage Area, acres.
Onsite, ft2
Offsite,ft2
40,11
1,245,196
501,996
1907.
830,689
None
23.1
1.003:622
None
9.4
409:464
None
9.12
397,140
None
bl. Total Impervious Surfaces, ft2
(1) Buildings/Lots
(2) Roads/Parking
(3) Other
(4) Offsite
465,462
315,180 *
101,495
31,363
17,424
221.407
172,620
43,124
5,663
None
334,310
144,480
103.004
86,826
None
1%1142
71820
57,935
23.087
None
194,735
144.000
28,750
21,985
None
b2. Total Impervious Surfaces, ft2
(1) Design Storm', 1.0 inches, ft2
(2) Design Storm', 1.5 inches, ft2
456,462
9,000 *
221,407
0
334,311
0
152:842
0
0
194,735
c. Design Storm, inches
1 8 1,5
1
1
1
1 .5
d. Pond Depth; feet
7.5
6.0
6.0
ZO
4.0
e. TSS removal efficiency
90
90
190
90
90
f. Permanent Pool Elev., FMSL
50.0
57.0
62.0
53.0
65.5
g. Perm. Pool Surface Area, ft'
49,482
10,972
15,150
9,028
24,487
h. Permitted Storage Volume, ft3
46,338
15,991
32,579
14,014
43,219
i. Temporary Storage Elev., FMSL
50.9
58.2
63.8
54.4
67.0
j. Controlling Orifice, "0 pipe
3
2
2
1.5
1.5
k. Permitted Forebay Volume, ft3
9,429
4,974
8,615
3,771
22,175
I. Receiving Stream/River Basin
Bishop Branch / Cape Fear
m. Stream Index Number
18-81-7-1
n. Classification of Water Body
C, Sw
o. Max. horsepower for a fountain
3/4 1/8 1/6 1/8 1/3
'Impervious Area Permitted per 15A NCAC 2H .1008, effective 9/1/95
'Impervious Area Permitted per 15A NCAC 2H .1008, effective 10/1/08
* A portion of lots are designed for 1.5" storm per 15A NCAC 2H .1008, effective 10/1/08
1>�Y971��1q��iI3�Zi7i 11>1I_W"
No homeowner/lot owner/developer shall fill in, alter, or pipe any drainage feature
(such as swales) shown on the approved plans as part of the stormwater
management system without submitting a revision to the permit and receiving
approval from the Division.
2. The permittee is responsible for verifying that the proposed built -upon area for
the entire lot does not exceed the maximum allowed by this permit. Once the lot
transfer is complete, the built -upon area may not be revised without approval
from the Division of Energy, Mineral and Land Resources, and responsibility for
meeting the built -upon area limit is transferred to the individual property owner.
3. If an Architectural Review Board or Committee is required to review plans for
compliance with the BUA limit, the plans reviewed must include all proposed
built -upon area. Any approvals given by the Board do not relieve the homeowner
of the responsibility to maintain compliance with the permitted BUA limit.
The Director may notify the permittee when the permitted site does not meet one
or more of the minimum requirements of the permit. Within the time frame
specified in the notice, the permittee shall submit a written time schedule to the
Director for modifying the site to meet minimum requirements. The permittee
shall provide copies of revised plans and certification in writing to the Director
that the changes have been made.
Page 4 of 10

State Stormwater Management Systems
Permit No. SW8 060238
The stormwater management system shall be constructed in its entirety,
vegetated and operational for its intended use prior to the construction of any
built -upon surface.
The permittee shall submit to the Director and shall have received approval for
revised plans, specifications, and calculations prior to construction, for any
modification to the approved plans, including, but not limited to, those listed
below:
a. Any revision to the approved plans, regardless of size.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area.
e. Further development, subdivision, acquisition, or sale of any, all or part of
the project area. The project area is defined as all property owned by the
permittee, for which Sedimentation and Erosion Control Plan approval or a
CAMA Major permit was sought.
f. Filling in, altering, or piping of any vegetative conveyance shown on the
approved plan.
7. The Director may determine that other revisions to the project should require a
modification to the permit.
8. All stormwater collection and treatment systems must be located in either
dedicated common areas or recorded easements. The final plats for the project
will be recorded showing all such required easements, in accordance with the
approved plans.
9. During construction, erosion shall be kept to a minimum and any eroded areas of
the system will be repaired immediately.
10. Upon completion of construction, prior to issuance of a Certificate of Occupancy,
and prior to operation of this permitted facility, a certification must be received
from an appropriate designer for the system installed certifying that the permitted
facility has been installed in accordance with this permit, the approved plans and
specifications, and other supporting documentation. Any deviations from the
approved plans and specifications must be noted on the Certification.
11. If the stormwater system was used as an Erosion Control device, it must be
restored to design condition prior to operation as a stormwater treatment device,
and prior to occupancy of the facility.
12. Permanent seeding requirements for the stormwater control must follow the
guidelines established in the North Carolina Erosion and Sediment Control
Planning and Design Manual.
13. The permittee shall at all times provide the operation and maintenance
necessary to assure that all components of the permitted stormwater system
function at optimum efficiency. The approved Operation and Maintenance Plan
must be followed in its entirety and maintenance must occur at the scheduled
intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowing and re -vegetation of side slopes.
d. Immediate repair of eroded areas.
e. Maintenance of side slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of structures, orifice, catch basins and
piping.
g. Access to all components of the system must be available at all times.
Page 5 of 10

State Stormwater Management Systems
Permit No. SW8 060238
14. Records of maintenance activities must be kept and made available upon
request to authorized personnel of DEMLR. The records will indicate the date,
activity, name of person performing the work and what actions were taken.
15. The facilities shall be constructed, operated and maintained in accordance with
the provisions of this permit, the approved plans and specifications, and the
supporting documents attached to this permit and on file with the Division.
16. Prior to the sale of any lot, the following deed restrictions must be recorded:
a. The following covenants are intended to ensure ongoing compliance with
State Stormwater Management Permit Number SW8 060238, as issued
by the Division of Energy, Mineral and Land Resources under NCAC
2H.1000.
b. The State of North Carolina is made a beneficiary of these covenants to
the extent necessary to maintain compliance with the Stormwater
Management Permit.
C. These covenants are to run with the land and be binding on all persons
and parties claiming under them.
d. The covenants pertaining to stormwater may not be altered or rescinded
without the express written consent of the State of North Carolina, Division
of Energy, Mineral and Land Resources.
e. Alteration of the drainage as shown on the approved plans may not take
place without the concurrence of the Division of Energy, Mineral and Land
Resources.
f. The maximum built -upon area per lot for the subdivision is as follows.
(Phase 1A) Lots 1 through 59, each allowed 3,500 square feet; (Phase
1 B) Lots 58 through 95, each allowed 3,000 square feet; (Phase 1 C
Sections 1 & 2) Lots 1 through 52 and Lots 87-88, each allowed 3,000
square feet; (Phase 1 C Section 3) Lots 53 through 86 and Lots 89-90,
each allowed 4,000 square feet; and (Phase 1A/1B multifamily) 60 units
each allowed 2,160 square feet. This allotted amount includes any built -
upon area constructed within the lot property boundaries, and that portion
of the right-of-way between the front lot line and the edge of the
pavement. Built upon area includes, but is not limited to, structures,
asphalt, concrete, gravel, brick, stone, slate, coquina and parking areas,
but does not include raised, open wood decking, or the water surface of
swimming pools.
g. All runoff on the lot must drain into the permitted system. This may be
accomplished through providing roof drain gutters, which drain to the
street, grading the lot to drain toward the street, or grading perimeter
swales and directing them into the pond or street. Lots that will naturally
drain into the system are not required to provide these measures.
h. Built -upon area in excess of the permitted amount will require a permit
modification.
17. A copy of the recorded deed restrictions must be submitted to the Division within
30 days of the date of recording the plat, and prior to selling lots. The recorded
copy must contain all of the statements above, the signature of the Permittee, the
deed book number and page, and the stamp/signature of the Register of Deeds.
18. Prior to transfer of the permit, the stormwater facilities will be inspected by
DEMLR personnel. The facility must be in compliance with all permit conditions.
Any items not in compliance must be repaired or replaced to design condition
prior to the transfer. Records of maintenance activities performed to date will be
required.
Page 6 of 10

State Stormwater Management Systems
Permit No. SW8 060238
19. Decorative spray fountains will be allowed in the stormwater treatment system,
subject to the following criteria:
a. The fountain must draw its water from less than 2' below the permanent
pool surface.
b. Separated units, where the nozzle, pump and intake are connected by
tubing, may be used only if they draw water from the surface in the deepest
part of the pond.
C. The falling water from the fountain must be centered in the pond, away from
the shoreline.
d. The maximum horsepower for the fountain's pump is based on the
permanent pool volume. The maximum pump horsepower for a fountain in
Pond #1 is 3/4, Ponds #4 & 6 is 1/8, Pond #5 is 1/6 and Pond #7 is 1/3.
III. GENERAL CONDITIONS
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
as iistea on the Corm, to the uivision of tnergy, iviinerai ana L
least 60 days prior to any one or more of the following events
a. An ownership change including 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:
b. The sale or conveyance of the common areas to a Homeowner's or Property
Owners Association, subject to the requirements of Session Law 2011-256;
c. Bankruptcy;
d. Foreclosure, subject to the requirements of Session Law 2013-121,
e. Dissolution of the partnership or corporate entity, subject to NCGS 57D-2-
01(e) and NCGS 57D-6-07;
f. A name change of the current permittee;
g A name change of the project;
h. A mailing address change of the permittee;
The permittee is responsible for compliance with all permit conditions until such
time as the Division approves the transfer request. Neither the sale of the project,
in whole or in part, nor the conveyance of common area to a third party
constitutes an approved transfer of the stormwater permit.
Approved plans and specifications for this project are incorporated by reference
and are enforceable parts of the permit.
4. Any individual or entity found to be in noncompliance with the provisions of this
stormwater management permit or the requirements of the Stormwater rules is
subject to enforcement procedures as set forth in NCGS 143 Article 21.
5. The issuance of this permit does not preclude the Permittee from complying with
any and all statutes, rules, regulations, or ordinances, which may be imposed by
other government agencies (local, state, and federal), which have jurisdiction.
6. In the event that the facilities fail to perform satisfactorily, including the creation of
nuisance conditions, the Permittee shall take immediate corrective action,
including those as may be required by this Division, such as the construction of
additional or replacement stormwater management systems.
7. The permit may be modified, revoked and reissued or terminated for cause. The
filing of a request for a permit modification, revocation and re -issuance or
termination does not stay any permit condition.
Page 7 of 10

State Stormwater Management Systems
Permit No. SW8 060238
The Permittee grants permission to staff of the DEMLR to access the property for
the purposes of inspecting the stormwater facilities during normal business
hours.
9. The permittee shall notify the Division in writing of any name, ownership or
mailing address changes at least 30 days prior to making such changes.
10. A copy of the approved plans and specifications shall be maintained on file by
the Permittee for a minimum of ten years from the date of the completion of
construction.
11. If the use of permeable pavement is desired, this permit must be modified to add
the permeable pavement conditions.
12. The permittee shall submit a permit renewal application request at least 180 days
prior to the expiration date of this permit. The renewal request must include the
appropriate documentation and the processing fee.
Permit modified, updated, and reissued this the loth day of October, 2017.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Division of Energy, Mineral and Land Resources
By Authority of the Environmental Management Commission
Page 8 of 10

r
DEMLR USE ONLY
Date Received
Fee Paid
Permit Number
Or; 3 17 'O-5- 7 Re✓.
$_50 .'
111 -3 f
O&OZ3
Applicable Ru es: ❑ Coastal SW -1995
❑ Coastal SW - 2008 ❑ Ph lI - 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.):
Grayson Park Phase 1
2. Location of Project (street address):
Intersection of Grayson Parkway and NC Hwy 87 (Maco Road)
City: Leland County: Brunswick Zip: 28451
3. Directions to project (from nearest major intersection):
Traveling south on US Hwy-17 turn right onto NC Hwy-87. Travel on Hwy-87 approximately 1.3 miles.
Protect is on the left at the intersection of NC-87 and Grayson Parkway.
4. Latitude: 34' 12' 00" N Longitude: 78° 05' 16" W of the main entrance to the project.
II. PERMIT INFORMATION:
1. a. Specify whether project is (check one): ❑New ®Modification ❑ Renewal w/ Modification'
'Renewals with modifications also requires SWU-102 — Renewal Application Form
b.If this application is being submitted as the result of a modification to an existing permit, list the existing
permit number SW8 060238 , its issue date (if known) 9/21/2006 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 tF%T
81ed ber,
if assigned, and the previous name of the project, if di�jj
proposed,
4. a. Additional Project Requirements (check applicable blanks; information on requpermits can b
obtained by contacting the Customer Service Center at 1-877-623-6748):
❑LAMA Major®Sedimentation/Erosion Control: 74.7 ac of Disturbed Area
❑NPDES Industrial Stormwater 0404/401 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:
Bruns-2006-190July 17 2006
5. Is the project located within 5 miles of a public airport? ®No ❑Yes
If yes, see S.L. 2012-200, Part VI: ham://12ortal.ncdenr.org/web/lr/rules-and-regulations
Form SWU-101 Version Oct. 31. 2013 Page I of 6

Ill. CONTACT INFORMATION
1. a. Print Applicant / Signing Official's name and title (specifically the developer, property owner, lessee,
designated government official, individual, etc. who owns the project):
Applicant/ Organization: Maco Road Partners, LLC
Signing Official & Title:Andrew Sandman, Member/ Manager
b.Contact information for person listed in item I above:
Street Address: 7101 Creedmoor Road, Suite 122
City: Raleigh State:NC
Zip:27613
Mailing Address (if applicable): 7101 Creedmoor Road, Suite 122
City: Raleigh State:NC
Zip:27613
Phone: [phone] Fax: (910
) 297-5397
Email: [e-mail]
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:
City:
Mailing Address (if
City:
Phone:
Fax:
3. a. (Optional) Print the name and title of another contact such as the project's construction supervisor or other
person who can answer questions about the project:
Other Contact
Signing Official &
b.Contact information for person listed in item 3a above:
Mailing Address:
City:
Phone:
d. Local jurisdiction for building permits:
Point of
Sta te:
Fax:
Phone #:
Form SWU-101 Version Oct. 31, 2013 Page 2 of

IV. PROJECT INFORMATION
1. In the space provided below, briefly summarize how the stormwater runoff will be treated.
Stormwater will be treated in wet detention basins.
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: Date:
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: 143.19 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*: 143.19 acres
Total project area shall be calculated to exclude thefollowing: the normal pool of impounded stnuctures, the area
between the banks of streams and rivers, the area below the Normal High Water (NHW) 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 (BUA). 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 = 21.9 %
9. How many drainage areas does the project have?5 (For high density, count 1 for each proposed engineered
stonnwater 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
Drainage Area _
Drainage Area _
Drainage Area _
Drainage Area _
Receiving Stream Name
SEE
ATTACHED
Stream Class *
Stream Index Number
Total Drainage Area (so
On -site Drainage Area (so
Off -site Drainage Area (so
Proposed Impervious Area** s
% Impervious Area** (total)
Impervious— Surface Area
Drainage Area
Drainage Area
Drainage Area _
Drainage Area _
On -site Buildings/Lots (so
On -site Streets (so
On -site Parking (so
On -site Sidewalks (st)
Other on -site (so
Future (so
Off -site (so
Existing BUA*** (so
Total (so:
Strearn Class and Index Number can be determined at: http.Ilportal.ncdetrr.orsfweb/wg[pslcsu/classiflrntions
Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
Form SWU-101 Version Oct. 31, 2013 Page 3 of

'Report only that amount of existing BUA that will remain after development. Do not report any existing BUA that
is to be removed and which will be replaced by new BUA.
11. How was the off -site impervious area listed above determined? Provide documentation.
Brunswick County GIS Aerial Photography
Projects in Union County: Contact DEMLR Central Ofjice staffto check ifthe project is located within a Threatened &
Endangered Species watershed that may be subject to more stringent stormwater requirements as per 15A NCAC 028.0600.
V. SUPPLEMENT AND O&M FORMS
The applicable state stormwater management permit supplement and operation and maintenance (O&M) forms
must be submitted for each BMP specified for this project. The latest versions of the forms can be downloaded
from http://portal.ncdenr.org/web/wq/--ws/­su/bml2-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 dots. 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 athft://portal.ncdenr.org/web/wq/ws/su/maps.)
Please indicate that the following required information have been provided by initialing in the space provided
for each item. All original documents MUST be signed and initialed in blue ink. Download the latest versions
for each submitted application package from http://portal.ncderinorg/web/wq/ws/su/statesw/forms does.
1. Original and one copy of the Stormwater Management Permit Application Form.
2. Original and one copy of the signed and notarized Deed Restrictions & Protective Covenants
Form. (if required as per Part VII below)
3. Original of the applicable Supplement Form(s) (sealed, signed and dated) and O&M 9agreement(s) for each BMP. � ,tt%�• gyp 9
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 Haters within 1/2 mile of the site boundary, include the 1/2
mile radius on the map.
7. Sealed, signed and dated calculations (one copy).
B. Two sets of plans folded to 8.5" x 14" (sealed, signed, & dated), including:
a. Development/Project name.
b. Engineer and firm.
c. Location map with named streets and NCSR numbers.
d. Legend.
e. North arrow.
f. Scale.
g. Revision number and dates.
h. Identify all surface waters on the plans by delineating the normal pool elevation of
impounded structures, the banks of streams and rivers, the MHW or NHW line of tidal
waters, and any coastal wetlands landward of the MHW or NHW lines.
• Delineate the vegetated buffer landward from the normal pool elevation of impounded
structures, the banks of streams or rivers, and the MHW (or NHW) of tidal waters.
i. Dimensioned property/project boundarywith bearings & distances.
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 measures.
in. Wetlands delineated, or a note on the plans that none exist. (Must be delineated by a
qualified person. Provide documentation of qualifications and identify the person who
made the determination on the plans.
PWJ - S'daiv-' L- 0
Form SWU-101 Version -Oct. 31, 2013 Page 4 of 6

n. Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations.
o. Drainage areas delineated (included in the main set of plans, not as a separate document).
p. Vegetated buffers (where required).
9. Copy of any applicable soils report with the associated SHWT elevations (Please identify �R ' Sa6tMr 0
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: 2158 Page No: 751 PC&Q-SuStAa7 E.O
11. For corporations and limited liability corporations (LLC): Provide documentation from the NC OW- SobWrreo
Secretary of State or other official documentation, which supports the titles and positions held
by the persons listed in Contact Information, item la, 2a, and/or 3a per 15A NCAC 21-1.1003(e).
The corporation or LLC must be listed as an active corporation in good standing with the NC
Secretary of State, otherwise the application will be returned.
http://www.secretary.state.nc.us/Corporations/CSearch.aspx
VII. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
For all subdivisions, outparcels, and future development, the appropriate property restrictions and protective
covenants are required to be recorded prior to the sale of any lot. If lot sizes vary significantly or the proposed
BUA allocations vary, a table listing each lot number, lot size, and the allowable built -upon area must be provided
as an attachment to the completed and notarized deed restriction form. The appropriate deed restrictions and
protective covenants forms can be downloaded from http://12ortal.ncdenr.org/web/lr/state-stormwater-
forms does. Download the latest versions for each submittal.
In the instances where the applicant is different than the property owner, it is the responsibility of the property
owner to sign the deed restrictions and protective covenants form while the applicant is responsible for ensuring
that the deed restrictions are recorded.
By the notarized signature(s) below, the permit holder(s) certify that the recorded property restrictions and
protective covenants for this project, if required, shall include all the items required in the permit and listed
on the forms available on the website, that the covenants will be binding on all parties and persons claiming
under them, that they will run with the land, that the required covenants cannot be changed or deleted
without concurrence from the NC DEMLR, and that they will be recorded prior to the sale of any lot.
VIII. CONSULTANT INFORMATION AND AUTHORIZATION
Applicant: Complete this section if you wish to designate authority to another individual and/or firm (such as a
consulting engineer and/or firm) so that they may provide information on your behalf for this project (such as
addressing requests for additional information).
Consulting Engineer: Elizabeth M Nelson, PE
Consulting Firm: Cape Fear Engineering, Inc.
Mailing Address: 151 Poole Road, Suite 100
City: Belville State:NC Zip: 28451
Phone: (910 ) 383-1044
Eniail:—[e-mail]
Fax: (910 ) 383-1045
IX. PROPERTY OWNER AUTHORIZATION (if Contact Information, item 2 has been filled out, complete this
section)
I, (print or type name of person listed in Contact Information, item 2a) , certify that I
own the property identified in this permit application, and thus give permission to (print or hjpe name of person
listed in Contact Information, item la) with (print or type 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.
Form SWU-101 Version Oct. 31, 2013 Page 5 of 6

As the legal property owner I acknowledge, understand, and agree by my signature below, that if my designated
agent (entity listed in Contact Information, item 1) dissolves their company and/or cancels or defaults on their
lease agreement, or pending sale, responsibility for compliance with the DEMLR Stormwater permit reverts back
to me, the property owner. As the property owner, it is my responsibility to notify DEMLR immediately and
submit a completed Name/Ownership Change Form within 30 days; otherwise I will be operating a stormwater
treatment facility without a valid permit. I understand that the operation of a stormwater treatment facility
without a valid permit is a violation of NC General Statue 143-215.1 and may result in appropriate enforcement
action including the assessment of civil penalties of up to $25,000 per day, pursuant to NCGS 143-215.6.
a Notary Public for the State of J 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 conmussion
X. APPLICANT'S CERTIFICATION
1, (print or type name of person listed in Contact Infornation, item 1a) Andrew Satdinan
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 stormwate rules under 15A NCAC 2H .1000 and any other applicable state stormwater re uirements.
Signature: Date:
%
I,` ,LO bra. N� • Ohny�r� a Notary Public four the State of NDAVACDrOU r0.„ County of
do hereby certify that Ay--, it eW Jcar�yrno�r-� personally appeared
before me this 1L dayof— 2 D I and ackry�wledge the due execution of the application for
a stormwater permit. Witness my hand and official seal,
M.
z
SEAL
My commission
11-2-0
Form SWU-101 Version Oct. 31, 2013 Page 6 of 6

10. Complete the following information for each drainagearea 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
Area 1 (Pond 1)*
Area 2 (Pond 4)
Receiving Stream Name
Bishop's Branch
Bishop's Branch
Receiving Stream Class/ Index No.
C;Sw (18-87-7-1)
C;Sw (18-81-7-1)
Total Drainage Basin Area (sf)
1,747,192
830,689
On -Site Drainage Area (sf)
1,245,196
830,689
Off -Site Drainage Area (sf)
501,996
0
Existing Impervious* Area (sf)
17,424
0
Proposed Impervious* Area (sf)
465,462
221,407
% Impervious* Area (total)
27%
27%
Impervious* Surface Area
Area 1 (Pond 1)
Area 2 (Pond 4)
On -Site Buildings (sf)
315,180
172,620
On -Site Streets (sf)
101,495
43,124
On -Site Parking (sf)
0
0
On -Site Sidewalks (sf)
31,363
5,663
Other On -Site (sf)
0
0
Off -Site (sf)
17,424
0
Total (sf)
465,462
221,407
Basin Information
Area 3 (Pond 5)
Area 4 (Pond 6)
Receiving Stream Name
Bishop's Branch
Bishop's Branch
Receiving Stream Class/ Index No.
C;Sw (18-87-7-1)
C;Sw (18-87-7-1)
Total Drainage Basin Area (sf)
1,003,622
409,464
On -Site Drainage Area (sf)
1,003,622
409,464
Off Site Drainage Area (sf)
0
0
Existing Impervious* Area (sf)
0
0
Proposed Impervious* Area (sf)
334,310
152,842
% Impervious* Area (total)
33%
37%
Impervious* Surface Area
Area 3 (Pond 5)
Area 4 (Pond 6)
On -Site Buildings (sf)
144,480
71,820
On -Site Streets (sf)
103,004
57,935
On -Site Parking (sf)
0
0
On -Site Sidewalks (sf)
20,876
23,087
Other On -Site (sf)
65,950
0
Off Site (sf)
0
0
Total (sf)
334,310
152,842
*NOTE: Pond #1 includes drainage area and impervious area draining through amenity Pond N2 and Pond ft3.

Basin Information
Area 5 (Pond 7) **
Receiving Stream Name
Bishop's Branch
Receiving Stream Class/ Index No.
C; Sw (18-87-7-1)
Total Drainage Basin Area (sf)
397,140
On -Site Drainage Area (sf)
397,140
Off -Site Drainage Area (sf)
0
Existing Impervious* Area (sf)
0
Proposed Impervious* Area (sf)
194,735
% Impervious* Area (total)
49%
Impervious* Surface Area
Area 5 (Pond 7)
On -Site Buildings (sf)
144,000
On -Site Streets (sf)
28,750
On -Site Parking (sf)
0
On -Site Sidewalks (sf)
3,485
Other On -Site (sf)
18,500
Off -Site (sf)
0
Total (sf)
194,735
**NOTE: Pond #7 includes drainage area and impervious area draining through amenity pond #8.

Elizabeth Nelson
From: Pusey, Steven <[e-mail]>
Sent: Tuesday, October 03, 2017 2:50 PM
To: Elizabeth Nelson
Subject: Grayson Park Phase 1C sec. 3 expansion
Importance: High
Elizabeth,
On the previous modification, you sized the ponds to handle the additional BUA at a 1.5" design storm in accordance
with the 2008 Rules. Now you are using a 1" storm for the additional BUA on Pond 7. Shouldn't you be using a 1.5"
design storm? Has anything changed to make it different now?
Thanks,
Steve
�CeUP Jr�St�r
Steve Pusey, Ell
Environmental Engineer
Division of Energy, Mineral and Land Resources — State Stormwater Program
Department of Environmental Quality
910 796 7215 office
910 796 7334 direct
steven.ousev@ ncdenr.aov
127 Cardinal Drive Ext
Wilmington, NC 28405
III a ".,aN..�r.«,a,,.., .
41 dtm(i R111.i,<f,
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
® Before printing this email, please consider your budget and the environment.
ECCI N G
OCT 0 5 2017
B fl—,

w.
CAPEFEAR
EN-G.IWEE RIN-
151 Poole Road, Suite 100
Belville, NC 28451
TEL [phone]
FAX [phone]
w .capefearengineering.com
To:
NCDEQ Stormwater
127 Cardinal_ Drive Extensiori
Wilmington, NC 28405
Attn: d
-Steve Pusey; EI.
Transmittal
Date: October 4, 2017
File: 820-01 "36"
Subject: Grayson Park
Stormwater Revision SW8 060238
Modification for 1C Section 3
❑ As Requested ❑ For Your Files ❑ For Distribution ® For your Review / Action / Approval
❑ Sent via Mail ❑ Sent via Courier
Quantity
Drawing No.
Description
2
Copies
Page 1 of SWU-101 revising 1.1. Project Name
1
Copy
Revised Wet Detention Basin Supplement SW401 for Pond #7 to reflect 1.5" design
storm
1
Copy
Revised Wet Detention Calculations for Pond #7 to reflect 1.5' design storm
3
Copies
Revised Design Plan Sheets 1-1, C-1 and P-1 (2 Full Size, 1 Reduced 11" x 17")
ECEIVER
ftf T n G 20p
-V
REMARKS In response to comments received by email 10/3/17 requesting 1.5' design storm.
Please note Design Plans Sheet 1-1 and C-1 have been revised per Town Planning Board approval
And Sheet P-1 has been revised to reflect a revised orifice per the revised calculations.
CC: File 820-01 "36 "
Cape Fear Engineering, Inc.
Signed:
Elizabeth M. Nelson, PE
Received
P:\820\820-01\ADMIMStormwaterW17 SW MOD PHASE I SECTION 3\2017-10 N SW Transmittal Resp to Commenis.dM

MINIMUM REQUIRED VOLUME (51MPLE METHOD BY TOM 5CHUELER):
Kv=0.05+0.009.0)
Rv= 0.491309
VOLUME= .5-Pv'Ad = 0.559913 AC -PT
= 24,390 7^3
VOLUME PROVIDED AT TEMPORARY POOL:
INCREM.
TOTAL
EL.
SA (5F) VOL. (CP)
VOL. (CF)
G5.5
24,487 0
0
- GG
25,327 13,2C4
13,204
G7
31,703 30,015
43,219
G8
35,171 33,437
7G,G5G
G9
38,723 3G,947
113,G03
MINIMUM TEMP. POOL
ELEVATION (FROM 51MPLE METHOD VOLUME):
PEO'D EL.=
GG.37
VOL. REQ'D =
24,390 CF
TEMP. POOL ELEVATION:
OUTLET EL. =
G7.00
VOL. PROV'D =
43,2) 9 CF
NOTE:
SINCE THE ELEVATION OF
THE NEXT AVAILABLE OUTLET ABOVE THE NORMAL
POOL 15 GREATER THAN THE
MINIMUM TEMP. POOL ELEVATION, THE OUTLET
ELEVATION 15 THE TEMPORARY POOL ELEVATION.
VOL. PROVE)= 43,219 > 24,390 =VOL. REQ'D OK
EGEI M L
OCT 0 5 2017
POND 7
D DATA SHEET
PAGE 2 OF 3
P:g2P 20 10-CA Pow] - 1.5,n

FORE13AY SIZING:
PERMANENT POOL VOLUME:
INCREM.
TOTAL
EL.
SA (5F)
VOL. (CF)
VOL. (CF)
60
9,733
0
O
GI
1 1,491
10,61 2
10,61 2
62
13,421
12,456
23,068
63
15,532
14,477
37,545
64
17,936
IG,734
54,279
65
20,858
19,397
73,676
65.5
24,467
11,336
65,012
REQ'D FOREBAY VOLUME =
14.735
CF
CHECK FORE13AY VOLUME
INCREM,
TOTAL
EL.
5A (5F)
VOL. (CF)
VOL. (CF)
60
I,566
0
0
61
2,105
1 ,836
1 ,836
62
2,724
2,415
4,250
63
3,427
3,076
7,326
64
4,326
3,877
11,202
65
5,638
4,582
16, 184
65.5
6,326
5,952
22, 1 66
PROV'D VOLUME = 22, 1 66 CF
VOL. PROV'D= 22, 1 66 - 14,735 =VOL. REQ'D OK 11
ORIFICE SIZING: REQ'D DRAWDOWN TIME = 2-5 DAYS
NOTE: ORIFICE SIZED TO DRAWDOWN THE TEMPORARY POOL IN 2-5 DAYS
Q2= O. 141 14 CF5 (FOR 2 DAY DRAWDOWN)
05= 0.05646 CF5 (FOR 5 DAY DRAWDOWN)
ORIFICE EL= 65.5 (PERM. POOL EL.)
TEMP. POOL EL = 67.00 (OUTLET EL)
ORIFICE DIAMETER = 2.0 IN.
O PROV'D= Cd'A'(2gh)^ 1/2 WHERE Cd= 0:6
A= 0.02162 SF
g= 32.2 FP5/5
h= (TEMP POOL -NORMAL POOL/3
0.5
Q PROV'D= 0.07428
Q2> 0.07428 >Q5 OK
DRAWDOWN TIME:
TIME = VOLUME = 24390 = 3.80 DAYS
Q PROV'D 0.07425
POND 7
DATA 511EET
PAGE 3 OF 3
P,B2W20-0J�1oN ND52017-10-0a?.nd 7-15.n

Casri:r, Jo
From:
Casmer, Jo
Sent:
Thursday, August 03, 2017 10:40 AM
To:
'[e-mail]'; '[e-mail]'
Subject:
Grayson Park; Stormwater Permit SW8 060238
The Wilmington Regional Office of the Division of Energy, Mineral, and Land Resources (Stormwater Section)
accepted the Stormwater Permit Application and $505.00 fee on August 3, 2017, 2017. The project has been
assigned to Steve Pusey and you will be notified if additional information is needed. Please be advised that no
construction activities may commence until the Stormwater Permit is issued.
Jo Casmer
Administrative Assistant for DEMLR/Stormwater Section
North Carolina Department of Environmental Quality
Department of Environmental Assistance & Customer Service
910 796-7336 office
910 350-2004 fax
jo.casmer(a)ncdenr.g ov
127 Cardinal Drive Extension
Wilmington. NC 28405
-Nothing • • • . -
H?� ar.
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
1

Completeness Review Checklist
Project Name:. rf S � _i�iICA IQC— Received Date:
Project yLoSation:t� y` �� ��jZM3 Accepted Date:
Rule(s) 2008 Coastal 199S Coastal MPhase II (WiRO.) Universal ❑1 88 Coastal
Type of Permit: New or Mod r PR Existing Permit # (Mod or PR): (p O a3 J nPE Cert on File?
Density: HD or LD Type: Commercial or Residential F—TCG:
%: �1% OK?) Stream Class: F-15A Map F-1Offsite to SW8
Subdivided?: Subdivision or Single Lot ORW Map F lExempt
Paperwork Emailed Engineer on:
� Supplement(s) (1 original per BMP) BMP Type(s):
F-1O&M with correct/original signatures (1 originol per BMP except LS/VFS and swales)
MKP'Plication with correct/original signatures El Deed
Corp or LLC: Sig. Auth. per SoS or letter MEmail Address: Design Engineer
sr505 (within 6mo) Email Address: Owner
❑Soils Report with SHWT Note 1
calculations (signed/sealed)
1:1No obvious errors U
nsity includes common areas, etc
Restrictions, if subdivided:
& Notarized
Plans z� t�
DI —Sets etails (roads, cul-de-sacs, curbs, sidewalks, BMPs, Buildings, etc)
GradingWetlands: Delineated or No Wetlands
cinity Map 0yout (proposed BUA dimensions)
�Iregend MDA Maps [Dpf-oi-ect Boundaries
tion Wet Pond
Is Report Soils Report
WT: �SHWT: -
ttom: PP:
Additional Information:
Permitted
BUA (sf)
DA (sf)
PP (el)
SHWT (el)
Depth (ft)
SA (sf)
Offsite
Cert for Master
)Deed Rest for Master
BUA Permitted (Master):
BUA Proposed (Offsite):
Lot #
Lot # Matches Master
sf
sf

CAPE FEAR
ENGINEERING
151 Poole Road, Suite 100
Belville, NC 28451
TEL [phone]
FAX [phone]
v .capefearengineering.com
To:
NCDEQ- Stormwater
127 Cardinal Drive Extension
Wilmington, NC 28405
Attn:
Linda Lewis
❑ As Requested ❑ For Your Files
❑ Sent via Mail ❑ Sent via Courier
Transmittal
Date: I July 26, 2017 1
I File: 1819-01 C Section 3 "36" 1
Grayson Park
Stormwater Revision SW8 060238
Modification for 1C Section 3
❑ For Distribution ® For your Review / Action / Approval
Quantity
Drawing No.
Description
1
Original
Check for $505
2
Original/Copy
Executed Stormwater Permit Application SWU-101 with drainage area attachments
2
Original/Copy
Executed High Density Residential Subdivision Deed Restrictions Form
1
Original
Wet Detention Basin Supplement SW401 for Pond #7
1
Original
Stormwater Narrative CLA4 Cykc.;- Lr-.h oAs
3
Copies
Design Plans for 1C Section 3, Cover, 1-1, C-1, SD-1, SD-2, P-1, P-2, SE-1, D-1, D-3
(2 Full Size 24" x 36", 1 Half Size 11" x 17")
3
Copies
Stormwater Management Plan, Sheet SW-1 (2 Full Size, 1 Reduced 11" x 17" Size)
REMARKS Delivery by hand.
CC: File 819-01 C Section 3 °36"
(File 819-01C"36")
JUL 2 i 2017
a
BY:
Cape Fear Engineering, Inc.
Signed:OC
Elizabeth M. Nelson, PE
Received
Date:
P M820-01%ADMIMStorm.te,t 017 SW MOD PHASE I SECTION W017d7-07 SW Trans.dtaldoo

Stormwater Design Narrative
And Calculations
For
NCDEQ Permitting
Subject:
Grayson Park Phase 1
Modification for SW8 060238
Brunswick County, North Carolina
CAg6""ii/
ZO QPpFEsslO,y9�/ 9
SEAL
030507
i����yeFTH, M
Prepared for
Maco Road Partners
7101 Creedmoor Road, Suite 122
Raleigh, NC 27613
[phone]
Date: July 2017
Prepared by
Cape Fear Engineering, Inc.
151 Poole Road, Suite 100
Belville, NC 28451
[phone]
ECEIVE
JUL 1 7 20?
BY:

STORMWATER NARRATIVE
Overview:
This submittal is to modify the existing Grayson Park Phase 1, permit number SW8 060238. The
proposed project is located off Maco Road (NC Hwy 87) in Brunswick County, North Carolina.
The modification proposed is to Phase I Section 3. The total number of lots remain 36, but the
lot lines are slightly modified for the revised plan. The allocation for each o iese 36 lots is
proposed to increase from the permitted 3000 SF to 4000 SF. Pond calculations are provided to
show that the existing pond design will accommodate the increased BUA allocations, so there
are no revisions to the stormwater treatment Pond #7 or Amenity Pond #8.

t
WET DETENTION BASIN DATA SHEET DATE: 7/7/201 7
DE51GN CALCULATIONS FOR PROJECT NO.: 520-01
GRAYSON PARK PHASE I C SECTION 3 DESIGNED BY: RAS
POND #7
DRAINAGE AREA (Ad) =
397,140
5Q.
FT 9.)2 ACRES
IMPERVIOUS AREA (Ai):
BUILDINGS:
144,000
SQ.
FT (3G LOTS AT 4,000 5F)
ROAD5:
25,750
50.
FT
SIDEWALKS:
3,455
50.
FT
OTHER:
0
50.
FT
RESERVE:
15,500
5Q.
FT
TOTAL:
194,735
5Q.
FT
PERCENT IMPERVIOUS (1)
I = Act/Ai = 43.03% U5E50 %
CALCULATE AVERAGE DEPTH (Davg):
SEE AVERAGE DEPTH CALCULATION SPREADSHEET FOR POND #7
CALCULATE REQUIRED SURFACE AREA AT PERMANENT POOL:
POND 7 SHALL HAVE AN AVERAGE DEPTH OF 4.0' AND BE DESIGNED TO REMOVE 90% T55.
INTERPOLATION OF TABLE 2 IN NCDENR STORMWATER BMP MANUAL
Ca? DEPTH = 4.0'
% IMP.
SA/DA
40
2.2G
50
2.79
GO
3.31
5A/DA= 2.79%
SAU,= I ,OGO 5F. = 0.25 AC
SURFACE AREA PROVIDED AT PERMANENT POOL (ELEV. G5.5) = 24,487 5F
5A PROV'D= 24.487 > I I ,0G0 =5A REQ'D OK
POND 7
DATA 5FIEtT
PAGE I OF 3
M2W20-0I1 Ic5WON05VO 17-7-7 POND 7 UPDATED DUA

MINIMUM REQUIRED VOLUME (51MPLE METHOD 13Y TOM 5CHUELER)
Rv=0.05+0.009'(I)
Rv=
0.491309
VOLUME=
1 .0"'Rv'Ad =
0.373275 AC -PT
=
IG,2GO FT^3
VOLUME PROVIDED AT
TEMPORARY
POOL:
INCREM. TOTAL
EL
SA (5F)
VOL. (CF) VOL. (CF)
G5.5
24,487
O 0
GG
28,327
13,204 13,204
G7
31,703
30,015 43,219
68
35,171
33,437 7G,G5G
G9
35,723
3G,947 113,GO3
MINIMUM TEMP. POOL
ELEVATION (FROM SIMPLE METHOD VOLUME):
REQ'D EL.—
GG. 10
VOL. REQ'D =
I G,2GO
CF
TEMP. POOL ELEVATION:
OUTLET EL. =
67.00
VOL. PROV'D =
43,219
CF
NOTE:
SINCE THE ELEVATION
OF THE NEXT AVAILABLE OUTLET A50VE THE NORMAL
POOL 15 GREATER THAN THE MINIMUM TEMP. POOL ELEVATION, THE OUTLET
ELEVATION 15 THE TEMPORARY POOL ELEVATION.
VOL. PROV'D= 43,2 15 > I G.260 =VOL. REQ'D OK
POND 7
DATA SHEET
PAGE 2 OF 3
P 1 20920-0I �c5W ND5�017-7-7 POND 7 UPDAiED 3UA

FORE BAY 51ZING:
PERMANENT POOL VOLUME
INCREM,
TOTAL
EL.
5A (5F)
VOL. (CF)
VOL. CF
GO
9,750
O
0
GI
1 1 ,490
1 0,G20
I0,C20
G2
13,421
12,45G
23,07G
G3
15,532
14,477
37,552
G4
17,93G
IG,734
54,28G
G5
20,858
19,397
73,G83
G5.5
24,467
11.33G
85,019
REQ'D FORE DAY VOLUME =
) 4,737
CF
CHECK FOREBAY VOLUME
INCREM.
TOTAL
EL.
5A (5F)
VOL. (CF)
VOL. (CF)
GO
1,583
O
0
GI
2,105
1,844
1,644
G2
2,724
2,415
4,250
G3
3,427
3,07G
7,334
G4
4,32G
3,877
1 1,21 1
G5
5,G38
4,952
1 G, 193
G5.5
G,32G
5,982
22,175
PROV'D VOLUME = 22,175 CF
VOL. PROV'D= 22,175 - 14,737 =VOL. REQ'D OK 11
ORIFICE 51ZING: REQ'D DRAWDOWN TIME = 2-5 DAY5
NOTE: ORIFICE SIZED TO DRAWDOWN THE TEMPORARY
POOL IN 2-5 DAYS
Q2=
0.09410 CPS
(FOR 2 DAY DRAWDOWN)
05=
0.037G4 CF5
(FOR 5 DAY DRAWDOWN)
ORIFICE EL.=
G5.5 (PERM. POOL
EL.)
TEMP. POOL EL. =
G7.00 (OUTLET EL.)
ORIFICE DIAMETER =
1.5 IN.
Q PROV'E)= Cd'A'(2gh)-
1/2 WHERE:
Cd= O.G
A= 0.01227 5F
g= 32.2 FFS/5
h= (TEMP POOL -NORMAL POOLY3
= 0.5
O PROV'D=
0.04178
Q2>
0.04178 >Q5
OK
DRAWOOWN TIME:
TIME =
VOLUME = I G2GO
= 4.50 DAYS
Q PROVD 0.04176
POND 7
DATA 5HEET
PAGE 3 OF 3
P,20620-OJb1l WND5�017-7-7 POND UPOA.FD BUA

AVERAGE DEPTH CALCULATION DATE: 7/7/201 7
DESIGN CALCULATIONS FOR PROJECT NO.: 520-01
GRAY50N PARK PHASE I C SECTION 3 DE51GNED BY: RA5
POND #7
ELEV.
(FT)
DEPTH
(FT)
SURFACE AREA
AT DEPTH.
(5F)
INC. VOL.
AT DEPTH.
(CF)
TOTAL VOL.
AT DEPTH.
(CF)
AVG. DEPTH
(FT)
G5.5
0.00
24,457
0
0
0.00
G5
0.50
20,859
1 1 ,33G
I 1 ,33G
0.4G
G4
1.50
17,93G
19,395
30,734
1.2G
G3
2.50
15,532
1 G,734
47,4G8
1.94
G2
3.50
1 3,42 1
14,477
G 1,945
2.53
G 1
4.50
1 1,490
1 2,45G
74,400
3.04
GO
5.50
9,750
1O,G20
55,021
3.47
P:\820\820-01 \calc5\P0ND5\201 7-7-7 POND 7 UPDATED 13UA
Option #2
Apt s,, tj =
20,659
5F
A ern, Vo l =
24,487
5F
Ab.t ,,,d =
9,750
5F
Depth =
5.00
PT
D,, =
4.13
FT
U5E 4.0 FT
POND #7
AVG. DEPTH
PAGE I OF I

Watershed Model Schematic
Hytlraflow Hydrographs Extension for AutoCAD® Civil 3D(D 2016 by Autodesk, Inc. v11
V5
�aP
Legend
Hyd, Origin Description
1 SCS Runoff POND 7 PRE
2 SCS Runoff POND 8 POST
3 SCS Runoff POND 7 POST
4 Reservoir POND 8 ROUTED
5 Combine POND 8 AND AREA 7
6 Reservoir POND 7 ROUTED
Project: pond 7 routing.gpw
Friday, 07 / 7 / 2017

z
Hydrograph Return Period Recap
Hyd Flow Hydrographs Extension for AutoCADO Civil 3DO 2016 by Autodesk, Inc. v11
Hyd.
Hydrograph
Inflow
Peak Outflow Ids)
Hydrograph
No.
type
hyd(s)
Description
(origin)
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
1
SCS Runoff
----
13.41
1920
---
29.37
38-84
53.53
66.26
81.71
POND 7 PRE
2
SCS Runoff
------
11.51
14.82
-------
20.23
25.06
32.36
38.60
46.11
POND 8 POST
3
SCS Runoff
----
14.86
19.14
-----
26.13
32.36
41.79
49.84
59.55
POND 7 POST
4
Reservoir
2
2.007
3.032
-------
4.832
8,615
17.43
25.64
34.68
POND 8 ROUTED
5
Combine
3,4
15.87
20,81
-------
29.05
36.55
50.71
68.10
8844
POND 8 AND AREA 7
6
Reservoir
5
1.640
3.498
-----
9.205
14.77
23.71
38.17
56.55
POND 7 ROUTED
Proj. file: pond 7 routing.gpw
Friday, 07 / 7 / 2017

Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D®2016 by Aulodesk, Inc. vl l
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
13.41
2
730
52,585
-----
----
---
POND 7 PRE
2
SCS Runoff
11.51
2
724
34,830
------
----
------
POND 8 POST
3
SCS Runoff
14.86
2
724
44,981
------
--- —
------
POND 7 POST
4
Reservoir
2.007
2
750
34,720
2
6Z08
16,755
POND 8 ROUTED
5
Combine
15.87
2
724
79.701
3,4
-----
----
POND 8 AND AREA 7
6
Reservoir
1.640
2
896
49,395
5
67,09
46,352
POND 7 ROUTED
pond 7 routing.gpw
Return Period: 1 Year
Friday, 07 / 7 / 2017

Hydrograph Report
4
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 1
POND 7 PRE
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 9.120 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.83 in
Storm duration
= 24 hrs
Q (cfs)
14.00
12.00
10.00
M
t+'�iI9l
4.00
2.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
POND 7 PRE
Hyd. No. 1 -- 1 Year
Friday, 07/7/2017
= 13.41 cfs
= 730 min
= 52,585 cuft
= 75
= Oft
= 10.00 min
= Type III
= 484
Q (cfs)
14.00
12.00
10.00
I
4.00
2.00
0.00 ' 1 ' 1 1 1 1 1 1 — 1 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 31DO 2016 by Autodesk, Inc. v11
Hyd. No. 2
POND 8 POST
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 3.980 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.83 in
Storm duration
= 24 hrs
Q (cfs)
12.00
WHOM
. II
4.00
PAil8]
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
POND 8 POST
Hyd. No. 2 -- 1 Year
Friday, 07 / 7 / 2017
= 11.51 cfs
= 724 min
= 34,830 cuft
= 88
= Oft
= 5.00 min
= Type III
= 484
Q (Cfs)
12.00
10.00
me:
MCI
4.00
2.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 2 Time (min)

t=
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Aulodesk, Inc. v11
Friday, 07 / 7 / 2017
Hyd. No. 3
POND 7 POST
Hydrograph type
= SCS Runoff
Peak discharge
= 14.86 cfs
Storm frequency
= 1 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 44,981 cuft
Drainage area
= 5.140 ac
Curve number
= 88
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.83 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
15.00
12.00
M
. M
3.00
0.00 '
0 120 240
Hyd No. 3
POND 7 POST
Hyd. No. 3 -- 1 Year
360 480 600 720 840
Q (cfs)
15.00
12.00
99119111
10.00
960 1080 1200 1320 1440
Time (min)

Hydrograph
Report
7
Hydraflow Hydrographs Extension for AutoCAD® Civil 3130 2016 by Autodesk, Inc. v11
Friday. 07 17 / 2017
Hyd. No. 4
POND 8 ROUTED
Hydrograph type
= Reservoir
Peak discharge
= 2.007 cfs
Storm frequency
= 1 yrs
Time to peak
= 750 min
Time interval
= 2 min
Hyd. volume
= 34,720 cuft
Inflow hyd. No.
= 2 - POND 8 POST
Max. Elevation
= 67.08 ft
Reservoir name
= POND 8
Max. Storage
= 16,755 cuft
Storage Indication method used
Q (cfs)
12.00
iGxdel
. rr
mill]
0.00 '
0 240
— Hyd No. 4
POND 8 ROUTED
Hyd. No. 4 -- 1 Year
480 720 960
— Hyd No. 2
Q (cfs)
12.00
10.00
4.00
2.00
0.00
1200 1440 1680 1920 2160 2400
Time (min)
l� Total storage used = 16,766 cult

Pond Report $
Hydraflow Hydrographs Extension for AutoCADV Civil 3D® 2016 by Autodesk, Inc. v11 Friday, 07 / 7 12017
Pond No. 2 - POND 8
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 66.50 It
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cult)
Total storage (cuft)
0.00
66.50
27,252
0
0
0.50
67.00
29,255
14,127
14,127
1.50
68,00
33,307
31,281
45,408
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in) = 24,00
0,00
0.00
0.00
Crest Len (ft)
= 16.00
40.00
0.00
0.00
Span (in) = 24.00
0.00
0.00
0.00
Crest El. (ft)
= 66.50
67.50
0,00
0.00
No. Barrels = 1
0
0
0
Weir Coeff.
= 3.33
2.60
3.33
3.33
Invert El. (ft) = 66.50
0.00
0.00
0.00
Weir Type
= 1
Broad
--
--
Length (ft) = 321.00
1
0.00
0.00
Multistage
= Yes
No
No
No
Slope (%) = 0.39
0.00
0.00
n/a
N-Value = .013
.013
.013
n/a
Orifice Coeff. = 0.60
0,60
0.60
0.60
Exfiil.(irt
= 0.000 (by
Contour)
Multi -Stage = n/a
No
No
No
TW Elev. (ft)
= 0.00
Note: CulveNOofice outflows are anall
under inlet (id) and outlet (oc) control Weir risers necked
for entice conditions (c) and submergence (s).
Stage / Storage / Discharge
Table
Stage Storage Elevation
Clv A
Clv B Clv C
PrfRsr Wr A
Wr B
Wr C
Wr D
Exfil User
Total
it cuft ft
cfs
cfs cfs
cfs cfs
cfs
cfs
cfs
cfs cfs
cfs
0.00 0 66.50
0.00
--- --
--- 0.00
0.00
---
---
-- ---
0.000
0.50 14,127 67.00
1.50 is
-- --
-- 0.00
0,00
--
--
- --
1,498
1.50 45,408 68.00
10.60
is
-- --
-- 0.00
36.77
--
---
-- --
47.37

9
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Friday, 07 / 7 / 2017
Hyd. No. 5
POND 8 AND AREA 7
Hydrograph type = Combine Peak discharge = 15.87 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 79,701 cult
Inflow hyds. = 3, 4 Contrib. drain. area = 5.140 ac
Q (cfs)
18.00
15.00
12.00
. M
CM
0.00 ` ' '
0 120 240
Hyd No. 5
POND 8 AND AREA 7
Hyd. No. 5 -- 1 Year
360 480 600
— Hyd No. 3
720
Q (cfs)
18.00
15.00
iNallL
E:2111111]
[llZ]
3.00
0.00
840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 4

10
Hydrograph
Report
Hydraflow Hydrographs Extension for AutoCAD@ Civil 3D® 2016 by Autodesk, Inc. v11
Friday, 07/7/2017
Hyd. No. 6
POND 7 ROUTED
Hydrograph type
= Reservoir
Peak discharge
= 1.640 cfs
Storm frequency
= 1 yrs
Time to peak
= 896 min
Time interval
= 2 min
Hyd. volume
= 49,395 cuft
Inflow hyd. No.
= 5 - POND 8 AND AREA 7
Max. Elevation
= 67.09 ft
Reservoir name
= POND 7
Max. Storage
= 46,352 cuft
Storage Indication method used
Q (cfs)
18.00
15.00
12.00
e m
. m
cM
0.00
0 600
— Hyd No. 6
POND 7 ROUTED
Hyd. No. 6 -- 1 Year
1200 1800 2400
— Hyd No. 5
3000 3600 4200 4800 5400
® Total storage used = 46,352 cult
Q (cfs)
18.00
15.00
12.00
3.00
1 0.00
6000
Time (min)

Pond Report
11
Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2016 by Autodesk, Inc. vi 1 Friday, 07 17 12017
Pond No. 1 - POND 7
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 65.50 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
0.00
65.50
0.50
66.00
1.50
67.00
2.50
68.00
3.50
69.00
Contour area (sgft)
24,487
28.327
31,703
35,171
38,723
Incr. Storage(cuft)
0
13,204
30,015
33,437
36,947
Total storage(cuft)
0
13,204
43,219
76,656
113,603
Culvert / Orifice Structures
Weir Structures
[A]
[B] [C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in) = 24.00
1.50 0.00
0.00
Crest Len (ft)
= 16.00
30.00
0.00
0.00
Span (in) = 24.00
1.50 0.00
0.00
Crest El. (ft)
= 67.00
68.00
0.00
0.00
No. Barrels = 1
1 0
0
Weir Coeff.
= 3.33
2.60
3.33
3.33
Invert El. (ft) = 65.50
65.50 0.00
0.00
Weir Type
= 1
Broad
---
Length (ft) = 53.00
1.00 0.00
0.00
Multi -Stage
= Yes
No
No
No
Slope (%) = 2.32
0.50 0.00
n/a
N-Value = .013
.013 .013
n/a
Orifice Coeff. = 0.60
0.60 0.60
0.60
Exfil.(in/hr)
= 0.000 (by
Contour)
Multistage = Na
Yes No
No
TW Elev. (ft)
= 0.00
Note. CulverVOnfce outflows are analyzed
under inlet hot and outlet mid Control Weir risers checked
for onnce conditions (to) and stbmemence (s).
Stage / Storage / Discharge Table
Stage Storage Elevation
CIv A
CIv B cIv C
PrfRsr Wr A
Wr 6
Wr C
Wr D
Exfil User
Total
It tuft ft
cfs
cfs cfs
cfs cfs
cfs
cfs
cis
cfs cfs
cfs
0.00 0 65.50
0.00
0.00 -
-- 0.00
0.00
--
--
-- --
0.000
0.50 13.204 66.00
0.04 is
0.04 is ---
-- 0,00
0,00
-
---
- ---
0.038
1.50 43,219 67.00
0.07 is
0.07 is ---
-- 0.00
0.00
---
---
-- ---
0.070
2.50 76,656 68,00
18.27 is
0.01 is ---
--- 18.24
s 0.00
--
--
-- ---
18.25
3.50 113,603 69.00
23.86 is
0.01 is ---
-- 23.79
s 78.00
--
---
-- --
101.80

12
Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
38.84
2
728
148,905
-----
----
------
POND 7 PRE
2
SCS Runoff
25.06
2
724
78.921
------
-----
----
POND 8 POST
3
SCS Runoff
32.36
2
724
101,923
-----
-----
------
POND 7 POST
4
Reservoir
8.615
2
738
78,803
2
67.58
32,126
POND 8 ROUTED
5
Combine
36.55
2
724
180,727
3,4
---
-----
POND 8 AND AREA 7
6
Reservoir
14.77
2
748
150,070
5
67.58
62,447
POND 7 ROUTED
pond 7 routing.gpw
Return Period: 10 Year
Friday, 07 / 7 / 2017

Hydrograph Report
13
HydraFlow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 1
POND 7 PRE
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 9.120 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.24 in
Storm duration
= 24 hrs
Q (cfs)
40.00
30.00
N 4 117
10.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
POND 7 PRE
Hyd. No. 1 -- 10 Year
0.00
0 120 240
Hyd No. 1
Friday, 07 / 7 / 2017
= 38.84 cfs
= 728 min
= 148,905 cuft
= 75
= Oft
= 10.00 min
= Type III
= 484
Q (Cfs)
40.00
30.00
20.00
10.00
r ata
360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)

14
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Friday, 07 / 7 12017
Hyd. No. 2
POND 8 POST
Hydrograph type
= SCS Runoff
Peak discharge
= 25.06 cfs
Storm frequency
= 10 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 78,921 cuft
Drainage area
= 3.980 ac
Curve number
= 88
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 7.24 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs
28.00
M11111111
16.00
12.00
M
4.00
POND 8 POST
Hyd. No. 2 -- 10 Year
Q (cfs)
28.00
24.00
W111111
16.00
12.00
4.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 2 Time (min)

Hydrograph Report
15
HydraFlow Hydrographs Extension for AutoCAD® Civil 31D® 2016 by Autodesk. Inc. v11
Hyd. No. 3
POND 7 POST
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 5.140 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.24 in
Storm duration
= 24 hrs
POND 7 POST
Q (cfs
35.00
afflI7
25.00
20.00
15.00
10.00
5.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Friday, 07 / 7 / 2017
= 32.36 cfs
= 724 min
= 101,923 cuft
= 88
= Oft
= 5.00 min
= Type III
= 484
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Time (min)
— Hyd No. 3

Hydrograph
Report
16
Hydraflow Hydrographs Extension for AutoCAD® Civil 300 2016 by Autodesk, Inc. v11
Friday. 07 17 / 2017
Hyd. No. 4
POND 8 ROUTED
Hydrograph type
= Reservoir
Peak discharge
= 8.615 cfs
Storm frequency
= 10 yrs
Time to peak
= 738 min
Time interval
= 2 min
Hyd. volume
= 78,803 cuft
Inflow hyd. No.
= 2 - POND 8 POST
Max. Elevation
= 67.58 ft
Reservoir name
= POND 8
Max. Storage
= 32,126 cult
Storage Indication method used
Q (cfs) Hyd. No. 4 -- 10 Year Q (cfs)
28.00 28.00
24.00 24.00
20.00 20.00
16.00 16.00
12.00 12.00
8.00 8.00
4.00 4.00
0.00 0.00
0 240 480 720 960 1200 1440 1680 1920
Time (min)
— Hyd No. 4 —Hyd No. 2 ®Total storage used = 32,126 tuft

Hydrograph Report
17
Hydraflow Hydrographs Extension for AutoCAD® Civil 3130 2016 by Autodesk, Inc. v11
Hyd. No. 5
POND 8 AND AREA 7
Hydrograph type
= Combine
Storm frequency
= 10 yrs
Time interval
= 2 min
Inflow hyds.
= 3, 4
Peak discharge
Time to peak
Hyd. volume
Contrib. drain. area
POND 8 AND AREA 7
Friday, 07 / 7 / 2017
= 36.55 cfs
= 724 min
= 180,727 cuft
= 5.140 ac
Q (cfs) Hyd. No. 5 -- 10 Year Q (cfs)
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 5 —Hyd No. 3 —Hyd No. 4

Hydrograph
Report
18
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk. Inc. v11
Friday, 07 / 712017
Hyd. No. 6
POND 7 ROUTED
Hydrograph type
= Reservoir
Peak discharge
= 14.77 cfs
Storm frequency
= 10 yrs
Time to peak
= 748 min
Time interval
= 2 min
Hyd. volume
= 150,070 cuft
Inflow hyd. No.
= 5 - POND 8 AND AREA 7
Max. Elevation
= 67.58 ft
Reservoir name
= POND 7
Max. Storage
= 62,447 cuft
Storage Indication method used
Q (cfs)
40.00
30.00
20.00
10.00
POND 7 ROUTED
Hyd. No. 6 -- 10 Year
Q (cfs)
40.00
30.00
10.00
0.00 ' 11 111 1 1 1 1 -1^ 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680
Hyd No. 6 Time (min)
— Hyd No. 5 ®Total storage used = 62,447 tuft

19
Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2016 by Autodesk. Inc. v11
Hyd.
No.
Hydrograph
type
(origin)
Peak
Flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
81.71
2
728
319,753
-----
------
------
POND 7 PRE
2
SCS Runoff
46A 1
2
724
150,872
----
-- —
------
POND 8 POST
3
SCS Runoff
59.55
2
724
194,845
------
-----
----
POND 7 POST
4
Reservoir
34.68
2
728
150,747
2
67.89
41,922
POND 8 ROUTED
5
Combine
88.44
2
724
345.592
3,4
---
---
POND 8 AND AREA 7
6
Reservoir
56.55
2
732
314.678
5
68.58
98,216
POND 7 ROUTED
pond 7 routing.gpw
Return Period: 100 Year
Friday, 07 / 7 / 2017

Hydrograph Report
Hydrallow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk. Inc. v11
Friday. 07 / 7 / 2017
Hyd. No. 1
POND 7 PRE
Hydrograph type
= SCS Runoff
Peak discharge
= 81.71 cfs
Storm frequency
= 100 yrs
Time to peak
= 728 min
Time interval
= 2 min
Hyd. volume
= 319,753 cuft
Drainage area
= 9.120 ac
Curve number
= 75
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 10.00 min
Total precip.
= 12.64 in
Distribution
= Type III
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
POND 7 PRE
Hyd. No. 1 -- 100 Year
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00 ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
21
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 2
POND 8 POST
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 3.980 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 12.64 in
Storm duration
= 24 hrs
Q (cfs)
50.00
40.00
30.00
10.00
0.00
0 120 240
Hyd No. 2
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
POND 8 POST
Hyd. No. 2 -- 100 Year
360 480 600 720 840
Friday, 07/7/2017
= 46.11 cfs
= 724 min
= 150,872 cuft
= 88
= Oft
= 5.00 min
= Type III
= 484
Q (cfs)
50.00
30.00
W1111181
10.00
0.00
960 1080 1200 1320 1440
Time (min)

Hydrograph Report
22
HydraFlow Hydrographs Extension for AutoCAM Civil 3D® 2016 by Autodesk, Inc. vt 1
Hyd. No. 3
POND 7 POST
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 5.140 ac
Basin Slope.
= 0.0 %
Tc method
= User
Total precip.
= 12.64 in
Storm duration
= 24 hrs
Q (cfs
60.00
50.00
40.00
30.00
20.00
10.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
POND 7 POST
Hyd. No. 3 -- 100 Year
Friday, 07 17 / 2017
= 59.55 cfs
= 724 min
= 194,845 cult
= 88
= Oft
= 5.00 min
= Type III
= 484
Q (cfs)
60.00
M8x1I11
40.00
30.00
20.00
I M1(1I17
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Time (min)
Hyd No. 3

Hydrograph Report
23
Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2016 by Autodesk, Inc. vt 1
Hyd. No. 4
POND 8 ROUTED
Hydrograph type
= Reservoir
Storm frequency
= 100 yrs
Time interval
= 2 min
Inflow hyd. No.
= 2 - POND 8 POST
Reservoir name
= POND 8
Storage Indication method used.
Q (cfs)
50.00
40.00
30.00
20.00
W11117
0.00
0 120 240
Hyd No. 4
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
POND 8 ROUTED
Hyd. No. 4 -- 100 Year
360 480 600
— Hyd No. 2
720
Friday, 07 / 7 / 2017
= 34.68 cfs
= 728 min
= 150,747 cult
= 67.89 ft
= 41.922 cuft
Q (Cfs)
50.00
30.00
20.00
10.00
' 0.00
840 960 1080 1200 1320 1440 1560
Time (min)
® Total storage used = 41,922 cult

24
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Friday, 07 / 7 12017
Hyd. No. 5
POND 8 AND AREA 7
Hydrograph type = Combine
Peak discharge
= 88.44 cfs
Storm frequency = 100 yrs
Time to peak
= 724 min
Time interval = 2 min
Hyd. volume
= 345,592 cuft
Inflow hyds. = 3,4
Contrib. drain. area
= 5.140 ac
Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
POND 8 AND AREA 7
Hyd. No. 5 -- 100 Year
Q (Cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00 I— ' — I 1 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 5 —Hyd No. 3 —Hyd No. 4

Hydrograph
Report
25
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk. Inc. v11
Friday. 07 / 7 / 2017
Hyd. No. 6
POND 7 ROUTED
Hydrograph type
= Reservoir
Peak discharge
= 56.55 cfs
Storm frequency
= 100 yrs
Time to peak
= 732 min
Time interval
= 2 min
Hyd. volume
= 314,678 cuft
Inflow hyd. No.
= 5 - POND 8 AND AREA 7
Max. Elevation
= 68.58 ft
Reservoir name
= POND 7
Max. Storage
= 98,216 cuft
Storage Indication method used
POND 7 ROUTED
Q (cfs) Hyd. No. 6 -- 100 Year Q (cfs)
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
000
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
000
0 120 240
360 480 600
720 840 960 1080 1200 1320 1440
1560
Time (min)
— Hyd No. 6
—Hyd No. 5
®Total storage used = 98,216 tuft

Hydraflow Rainfall Report
Hydra0ow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Return
Period
Intensity -Duration -Frequency Equation Coefficients (FHA)
(yrs)
B
D
E
(NIA)
1
81.8155
12.8000
0,8927
--------
2
89.6877
12.6000
0.8707
---- ---
3
0.0000
0.0000
0,0000
-------
5
98.3564
12.9000
0.8409
-----
10
984972
12.6000
0.8087
-------
25
86.1743
11.1000
0.7415
---
50
81.3332
10.4000
0,7034
----- --
100
74.7444
9.3000
0.6599
------
File name: ILM PER 8.03.9.10F
Intensity = B / (Tc + D)^E
Friday, 07 / 7 / 2017
Return
Period
Intensity Values (in/hr)
(yrs)
5 min
I 10
15
20
25
30
35
40
45
50
55
60
1
6.26
5.02
4.20
3,63
3.20
2.86
2.59
2.37
2A9
2.03
1.90
1.78
2
7.38
5.94
4.99
4.32
3.81
3.42
3.10
2.85
2.63
2A5
2.29
2.15
3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0,00
0.00
0.00
5
8.70
7.07
5.99
5.21
4.63
4.17
3.80
3.50
3.24
3.02
2.83
2.67
10
9.69
7.91
6.73
5.88
5.24
4.74
4.33
4.00
3,71
3.47
3.26
3,08
25
10.98
8.98
7.67
6.74
6.03
5A8
5.03
4.66
4.35
4,08
3.85
3.65
50
11.88
9.75
8.36
7.37
6.62
6.03
5.55
5.16
4.83
4.54
4.30
4.08
100
12.92
10.60
9.11
8.05
7.25
6.63
6.13
5.71
5.36
5.05
4.79
4.56
Tc = time in minutes. Values may exceed 60.
Precip. file name: L:\Civil\CALCS\Stormwater\ILM SCS PER 8.03.35.pcp
Rainfall Precipitation Table (in) 1
storm
Distribution
1-yr.
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
SCS 24-hour
3.83
4.66
0.00
6.02
7.24
9.10
1070
12.64
SCS 6-Hr
0.00
3.38
0.00
0,00
5.20
6.49
0,00
8.93
Huff-1 sl
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-2nd
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
Huff-3rd
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-4th
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-Indy
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0,00
Custom
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

Hydraflow Table of Contents
pond 7 rouling.gpw
HydraFlow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Friday, 07 / 7 / 2017
Watershed Model Schematic..................................................................................... 1
Hydrograph Return Period Recap............................................................................. 2
1 -Year
SummaryReport .........................................................................................................................
3
HydrographReports
...................................................................................................................
4
Hydrograph No.
1, SCS Runoff, POND 7 PRE........................................................................
4
Hydrograph No.
2, SCS Runoff, POND 8 POST......................................................................
5
Hydrograph No.
3, SCS Runoff, POND 7 POST......................................................................
6
Hydrograph No.
4, Reservoir, POND 8 ROUTED....................................................................
7
PondReport
- POND 8........................................................................................................
8
Hydrograph No.
5, Combine, POND 8 AND AREA 7...............................................................
9
Hydrograph No.
6, Reservoir, POND 7 ROUTED. .................................................................
10
PondReport
- POND 7...................................................................................................
11
10 -Year
SummaryReport .......................................................................................................................
12
HydrographReports
.................................................................................................................
13
Hydrograph No.
1, SCS Runoff, POND 7 PRE......................................................................
13
Hydrograph No.
2, SCS Runoff, POND 8 POST....................................................................
14
Hydrograph No.
3, SCS Runoff, POND 7 POST....................................................................
15
Hydrograph No.
4, Reservoir, POND 8 ROUTED..................................................................
16
Hydrograph No.
5, Combine, POND 8 AND AREA 7.............................................................
17
Hydrograph No.
6, Reservoir, POND 7 ROUTED..................................................................
18
100 - Year
SummaryReport .......................................................................................................................
19
HydrographReports.................................................................................................................
20
Hydrograph No.
1, SCS Runoff, POND 7 PRE......................................................................
20
Hydrograph No.
2, SCS Runoff, POND 8 POST....................................................................
21
Hydrograph No.
3, SCS Runoff, POND 7 POST....................................................................
22
Hydrograph No.
4, Reservoir, POND 8 ROUTED..................................................................
23
Hydrograph No.
5, Combine, POND 8 AND AREA 7.............................................................
24
Hydrograph No.
6, Reservoir, POND 7 ROUTED..................................................................
25
OFReport .................................................................................................................. 26