SW8981039_Historical File_19990412

April 12, 1999 oY�c \nog,‘ poi- -b yr d
Mr. E.Bryan English,Manager or Pt L.Q, I
MIK-B,LLC
4186 Shearwater Way
Southport,NC 28461
Subject: Permit No. SW8 981039
Old Georgetown Center
High Density Stormwater Project
Brunswick County
Dear Mr. English:
The Wilmington Regional Office received the Stormwater Management Permit Application for Old Georgetown Center
on Octobr 30, 1998, with fmal information on February 3, 1999. 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
2H.1000. We are forwarding Permit No. SW8 981039 dated April 12, 1999, for the construction of Old Georgetown
Center.
This permit shall be effective from the date of issuance until April 12, 2009, and shall be subject to the conditions and
limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this
permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system will
result in future compliance problems.
If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an
adjudicatory hearing upon written request within thirty(30)days following receipt of this permit. This request must be in
the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the
Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this
permit shall be fmal and binding.
If you have any questions, or need additional information concerning this matter, please contact Linda Lewis, or me at
[phone].
Sincerely,
Rick Shiver
Water Quality Regional Supervisor
RSS/arl: S:\WQS\STORMWAT\PERMIT\981039.APR
cc: John Klein,P.E.
Delaney Aycock,Brunswick County Inspections
Joanne Steenhuis,DWQ
Linda Lewis
Wilmington Regional Office
Central Files

State Stormwater Management Systems
Permit No. SW8 981039
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other
applicable Laws,Rules,and Regulations
PERMISSION IS HEREBY GRANTED TO
MIK-B, LLC
Old Georgetown Center
Brunswick County
FOR THE
construction, operation and maintenance of a detention pond in compliance with the provisions of 15A NCAC 2H .1000
(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 Water Quality and considered a part of
this permit.
This permit shall be effective from the date of issuance until April 12, 2009 and shall be subject to the following specified
conditions and limitations:
I.DESIGN STANDARDS
1. This permit is effective only with respect to the nature and volume of stormwater described in the application and
other supporting data.
2. This stormwater system has been approved for the management of stormwater runoff as described on page 3 of
this permit, the Project Data Sheet. The stormwater control has been designed to handle the runoff from 92,476
square feet of impervious area.
3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the
permit.
4. The tract will be limited to the amount of built-upon area indicated on page 3 of this permit, and per approved
plans.
DIVISION OF WATER QUALITY
2.

State Stormwater Management Systems
Permit No. SW8 981039
PROJECT DESIGN DATA SHEET
Project Name: Old Georgetown Center
Permit Number: SW8 981039
Location: Brunswick County
Applicant: Mr. E. Bryan English,Manager
Mailing Address: MIK-B,LLC
4186 Shearwater Way
Southport,NC 28461
Application Date: Octobr 30, 1998
Water Body Receiving Stormwater Runoff: Dutchman Creek(CFR 18-88-9-3-(1))
Classification of Water Body: "SC Sw HQW"
If Class SA, chloride sampling results: n/a
Pond Depth,feet: 6.5
Permanent Pool Elevation,FMSL: 19
Total Impervious Surfaces,ftz: 92,476
Offsite Area entering Pond,ft2: None,per Engineer
Required Surface Area,ftz: 4,626
Provided Surface Area,ft2: 4,940
Required Storage Volume, ft3: 7,416
Provided Storage Volume, ft3: 8,685
Temporary Storage Elevation,FMSL: 20.5
Controlling Orifice: 1.25"_pipe
H. SCHEDULE OF COMPLIANCE
3

State Stormwater Management Systems
Permit No. SW8 981039
1. The stormwater management system shall be constructed in it's entirety,vegetated and operational for its intended
use prior to the construction of any built-upon surface except roads.
2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired
immediately.
3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted
stormwater system functions 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 revegetation 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 outlet structure, orifice device and catch basins and piping.
g. Access to the outlet structure must be available at all times.
4. Records of maintenance activities must be kept and made available upon request to authorized personnel of
DWQ. The records will indicate the date, activity, name of person performing the work and what actions were
taken.
5. Decorative spray fountains will not be allowed in the stormwater treatment system.
6. The facilities shall be constructed as shown on the approved plans. This permit shall become voidable unless the
facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications,
and other supporting data.
7. 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.
8. 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.
9. Prior to the sale of any portion of the property, an access/maintenance easement to the stormwater facilities shall
be granted in favor of the permittee if access to the stormwater facilities will be restricted by the sale of any
portion of the property.
10. The permittee is responsible for verifying that the proposed built-upon area does not exceed the allowable
built-upon area.
11. The runoff from all built-upon area on the project must be directed into the permitted stormwater control system.
12. 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.
13. The following items will require a modification to the permit:
4

State Stormwater Management Systems
Permit No. SW8 981039
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 subdivision of the project area.
f. Filling in,altering,or piping of any vegetative conveyance shown on the approved plan.
In addition, the Director may determine that other revisions to the project should require a modification to the
permit.
14. 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.
III. GENERAL CONDITIONS
1. This permit is not transferable. In the event there is a desire for the facilities to change ownership, or there is a
name change of the Permittee, a formal permit request must be submitted to the Division of Water Quality
accompanied by an application fee, documentation from the parties involved, and other supporting materials as
may be appropriate. The approval of this request will be considered on its merits and may or may not be
approved.
2. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to
enforcement action by the Division of Water Quality, in accordance with North Carolina General Statute
143-215.6A to 143-215.6C.
3. 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.
4. 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.
5. The permittee grants DENR Staff permission to enter the property for the purpose of inspecting all components of
the permitted stormwater management facility.
6. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit
modification, revocation and reissuance or termination does not stay any permit condition.
Permit issued this the 12th day of April, 1999.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Kerr. T. Stevens,Director
Division of Water Quality
By Authority of the Environmental Management Commission
Permit Number SW8 981039
Old Georgetown Center
5

State Stormwater Management Systems
Permit No. SW8 981039
Stormwater Permit No. SW8 981039
Brunswick County
Engineer's Certification
I, _, as a duly registered Professional Engineer in the State of North
Carolina,having been authorized to observe(periodically/weekly/full time)the construction of the project,
(Project)
for (Project Owner) hereby state that, to the best of my abilities, due care and
diligence was used in the observation of the project construction such that the construction was observed to be built within
substantial compliance and intent of the approved plans and specifications.
Noted deviations from approved plans and specification:
SEAL
Signature
Registration Number _
Date

Revised 1-28-99
STORM DRAINAGE CALCULATIONS (revised)
for
OLD GEORGETOWN CENTER -
NC HIGHWAY 211
BRUNSWICK COUNTY,NORTH CAROLINA
PREPARED FOR
MIK B, L.L.C.
4186 Shearwater Way
Southport,NC 28461
[phone]
January 1999
FILE NO.: 98009 STORM WATER
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PREPARED BY
KLEIN ENGINEERING AND ASSOCIATES
3410 Wrightsville Avenue
WILMINGTON,NC 28403
[phone]

KLEIN ENGINEERING AND ASSOCIATES
PROJECT: Old Georgetown Center PROJECT NO.: 98009
CLIENT: MIK-B, l.l.c. DATE: October 1998
LOCATION: Brunswick County, NC PREPARED BY: JKK
SUBJECT: Stormwater Calculations
GIVEN: Design for single collection pond.
Runoff Coefficients used for Design:
Impervious= 1.00
Turf(developed) = 0.20
TOTAL PROJECT AREA= 133924 SF = 3.07 Ac
Area draining to pond= 115273 SF = 2.65 Ac
Areas not draining to pond = 18651 SF = 0.43 Ac
Design Storm Event= 10-year, 5 minute duration
Rainfall Intensity= 7.23 inches/hour
SOLUTION:
1. Summary of Drainage Areas
AREAS DRAINING
TO POND
AREA AREA
TYPE (SF) (AC)
BLDG 30914 0.710
SIDEW 8583 0.197
PVMNT 52979 1.216
TOTAL IMPERV. 92476 2.123
TURF 22797 0.523
TOTALS 115273 2.65
Pond Design Criteria:
Percent Built-Upon: = 2.123 Ac / 2.646 Ac =
80.2 % use: 81 %
2. STORM DRAINAGE DESIGN: 10-Year, 5-Minute Storm, i= 7.23 In/hr
Weighted Runoff Coefficient= 0.927 USE: 0.93
REFER TO STORM DRAIN ROUTING CALCULATIONS FOR PIPING DESIGN
CUMUL
DRAINAGE AREA RUNOFF RUNOFF LENGTH UPPER
INLET C (SF) (ac) (CFS) (CFS) (LF) TOP
K 0.93 14730 0.34 2.3 2.3 128 23.85
J 0.93 9215 0.21 1.4 3.7 128 23.85
98009-Old Georgetown Center(rev 1-28-99)

KLEIN ENGINEERING AND ASSOCIATES
0.93 10570 0.24 1.6 1.6 94 26.55
H 0.93 11665 0.27 1.8 1.8 136 27.30
C 0.93 7624 0.18 1.2 4.6 62 26.75
F 0.93 8751 0.20 1.4 6.0 104 26.70
E 0.93 17830 0.41 2.8 8.7 120 26.50
D 0.93 10777 0.25 1.7 10.4 120 26.50
C 0.93 5624 0.13 0.9 11.2 120 23.85
B 0.93 0 0 0.0 11.2 14 24.00
A 0.93 7998 0.18 1.2 16.2 18 23.25
FES 0.93 0 0 0.0 16.2
104784 2.41
POND 10489 0.24
TOTALS 115273 2.65
Note: Pipes based on RCP with n =0.013.
3. DETENTION POND DESIGN:
Design to store the first 1-inch of runoff from project area
Imperv. 1.00 x 92476 SF x 1'/12" = 7706
Turf 0.20 x 22797 SF x 1'/12" = 380
8086 CF
Based on state requirements for ponds without vegetative filter
and using the design impervious percent o' 81 with a depth of 6.5
feet,the ratio of surface area(SF)to drainage area to drainage area(DA) = 4.06
Therefore, required pond surface area(SA) is:
4.06 x 2.65 /100= 0.11 Acres
4680 SF Use: 4940 SF
Pond Width at Design Surface: see plan
Pond Length at Design Surface: see plan
AVE. CUMUL.
AREA AREA VOLUME VOLUME
ELEV. (SF) (SF) (CF) (CF)
12.5 83 (Pond Design Bottom)
263 131 131
13.0 442
617 617 748
14.0 791
1016 1016 1764
15.0 1241
1517 1517 3280
16.0 1792
2119 2119 5399
17.0 2445
98009-Old Georgetown Center(rev 1-28-99)

KLEIN ENGINEERING AND ASSOCIATES
2822 2822 8220 (Storage Below Permanent Pool)
18.0 3198
4069 4069
19.0 4940 0 (Design Area)
5442 5442
20.0 5944 5442
6486 6486
21.0 7027 11928
7608 7608
22.0 8189 19536
Depth where storage requirement met: 20.41
Depth of Required Storage: 1.41 VF or 16.9 Inches
Elevation of Top of Riser: 20.50
Depth of Storage Provided: 1.50 VF or 18.0 Inches
Volume of Storage Provided: 8685 CF
4. Restrictive Orifice Design:
Design orifice for discharge allowed using the following equation
Q=C xAx(2gh)"0.5 where: Q = CFS
C =orifice coefficient
A=orifice diameter(SF)
g=32.2 ft/sec2
h=pressure head(ft)
Rearranging the above equation to solve for hole diameter
A= Q/Cx(2gh)"0.5
For our type of discharge, C= 0.60
Pond Outlet Invert= 19.00
Design Storage Level = 20.50
Ave Reqd Storage Level= 19.75
Trial Orifice Diameter= 1.25 inches
Orifice centerline= 19.05
Ave. Pressure Head(h)= 0.70
Allowable discharge rate:
Design discharge so that ponds drain between two(2)day and five(5)days.
Pond Volume: 8685 CF Pond Volume: 8685 CF
Time to drain: 2 days Time to drain: 5 days
or 172800 sec or 432000 sec
Therefore, release rate= Therefore, release rate=
8685 CFS / 172800 sec 8685 CFS / 432000 sec
or 0.050 CFS or 0.020 CFS
A= 0.0125 SF A= 0.0050 SF
1.51 inches 0.96 inches
Use: 1.25 "
5. Forebey Design Requirements: (revised 1-28-99)
Design forebay for 20 %of the total volume below permanent pool.
Total Pond Volume= 8220 CF (see above)
98009-Old Georgetown Center(rev 1-28-99)

KLEIN ENGINEERING AND ASSOCIATES
Required Forebay volume= 1644 CF
AVE. CUMUL.
AREA AREA VOLUME VOLUME
ELEV. (SF) (SF) (CF) (CF)
15 1
33.5 33.5
16.0 66 33.5
127 160
17.0 187 194
278 438
18.0 368 631
605 1043
19.0 842 1674
Therefore, design forebay volume= 1674 CF or 20.4 %or Storage Volume
6. Pond Outlet Design
Design pond outlet pipe to convey runoff in excess of 1-inch generated from a 10-year storm event.
Tc Rate Depth
(min) (in/hr) (in) Comments
5 7.23 0.6 less than pond storage
10 6.3 1.1 approx. pond storage
15 5.45 1.4 exceeds storage use
Q =CxixA C = 0.93
i = 5.45 in/hr
A= 2.65 Ac
Q= 13.4 CFS
REQ'D DESIGN
RUNOFF DIA SLOPE SLOPE LENGTH UPPER LOWER
(CFS) (IN) (%) (%) (LF) INVERT INVERT Comments
13.4 18 1.63 2.00 40 22.00 21.20 use
24 0.35 0.50 40 22.00 21.80
7. Overflow Weir Design for Forebay and Pond Emergency Spillway
Design Overflow Weir based on 25-year, 10-minutes storm which produce a volume
in excess of one(1) inch.
Q =CxixA C= 0.93
i = 7.13 in/hr
A= 2.65 Ac
Q= 17.5 CFS
Design weir to convey entire flow. Set weir invert above storage level.
weir equation: Q = C x H^312 x(L-0.2H) where:
Q = CFS
C=weir coefficient= 3.33
98009-Old Georgetown Center(rev 1-28-99)

KLEIN ENGINEERING AND ASSOCIATES
L=weir lengh (FT)=2 x H (min)
H=head (FT)
rearranging and solving for weir length yields the following:
L=(Q/CxHA3/2) +0.2H
Design weir capacity= 17.55 CFS
Design weir depth 6 " = 0.5 FT
Therefore, required weir length =
15.00 FT use: 15 FT
8. Summary:
Required Pond Surface Area= 4680 SF
Design Pond Surface Area= 4940 SF
Required Storage Volume= 8086 CF
Design Storage Volume= 8685 CF
Pond Outlet Invert= 19.00
Required Storage Elev. = 20.41 Depth = 1.41 VF
Design Storage Elevation = 20.50 Depth= 1.50 VF
Pond Invert= 12.50
Outlet Orifice Diameter= 1.25 "
Ave Discharge Rate = 0.034 CFS
Anticipated drawdown time 65.5 Hours = 2.7 Days
98009-Old Georgetown Center(rev 1-28-99)

DESIGN NARRATIVE
1. GENERAL:
The project site is located east of the intersection of NC Highway 211 (Southport Supply Road) and S.R 133
(Longbeach Road)within Brunswick County. Located on a site approvi*nately 3.07 acres,the proposed ultimate
development will require approximately 2.65 acres of built-upon area.
The purpose of this submittal is to design the detention facility for of the site, Included within this submittal
are the Drawings, Storm Drainage Calculations,and Operation and Maintenance Plan. All items are part of the
overall plan and included by reference.
2. EXISTING SITE:
Site topography at the site is pitched toward the western and southern property lines into the existing
Dutchman's Creek tributary. Grades are moderately sloping with grades getting steeper as one approaches the
ditch corridor.
3. PROPOSED IMPROVEMENTS:
Grading and drainage improvements include grading for both pond and general sitework. Grades have been
constructed to discourage overland flow of runoff into the parking areas from non-built upon areas and offsite
drainage areas. All built-upon areas within the confines of the tract have been designed to be piped into the
proposed wet detention basin.
4. STORM DRAINAGE CALCULATIONS:
Storm drainage calculations were aimed at satisfying NCDENR requirements as well as considerations for
sedimentation and erosion control. Storm drain piping was designed using the routing methods and the
HydraFlow software package; the storm drain detention pond was sized in accordance with Division of Water
Quality requirements. Storm drain piping has been designed to convey the ten (10)year storm while the pond
emergency spillway has been designed to convey the twenty-five (25)year storm.

Page Two
Design Narrative
Old Georgetown Center
Design considerations included,but not limited to, the following items:
a. Storage of the first one(1)inch of runoff
b. Release of the stored volume between two(2)and five (5) days
c. Use of forebay to promote solid deposition within the pond inlet area.
5. EROSION CONTROL CONSIDERATIONS:
Land disturbance for this submittal will be extensive with much of the existing vegetation and topography being
altered to suit the project design. The initial step of the work will be aimed at reshaping the existing ditch.
Agreements with the adjoining property owners have been made to facilitate this work. Subsequent work shall
be to install the pond to assist in sedimentation and erosion control needs during construction.
Refer to the Drawings for additional details for the project site. These details include but are not limited to the
following:
a. use of temporary seeding should construction be halted for the specified time limit(see plan)
b. use of flared-end sections with rip-rap at the
pipe ends
c. use of end-of-day piping protection during construction of storm drainage piping
d. use of silt fencing is indicated where applicable
e. use of construction entrances
f. use of inlet protection at each inlet until vegetative establishment
6. MAINTENANCE CONSIDERATIONS:
During construction,the Contractor shall be required to inspect and repair as needed all erosion control devices
after any significant rain event. Any measure found not performing it's intended function, shall be repaired
immediately. Upon completion of construction and establishment of permanent ground cover,the Owner shall
be responsible for maintenance on the project site.
Refer to attached Storm Water Management Operation and Maintenance Plan for additional requirements during
both initial construction and completion.