SW8040916_CURRENT PERMIT_20041001

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

STORMWATER DIVISION CODING SHEET
PERMIT NO,
DOC TYPE
❑ FINAL PERMIT
❑ MONITORING REPORTS
❑ APPLICATION
❑ COMPLIANCE
❑ OTHER
DOC DATE
❑
YYYYM M D D

Michael F. Easley, Governor
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
October 1, 2004
Mr. Sterling Cheatham, City Manager
City of Wilmington
PO Box 1810
Wilmington, NC 28402
Subject: Stormwater Permit No.-SW8 040916
Wilmington Police Headquarters .
High Density Project
New Hanover County
Dear Mr. Cheatham:
The Wilmington Regional Office received a complete Stormwater Management Permit
Application for Wilmington Police Headquarters on September 30, 2004. 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 040916 dated October 1, 2004, for the construction of the subject project.
This permit shall be effective from the date of issuance until October 1, 2014, 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 oflthis 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 final 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
Regional Supervisor
Surface Water Protection Section
RSSlarl: S:1WQSISTORMWATIPERMIT1040916.oct04
CC.' Mark Hargrove, P.E.
Tony Roberts, New Hanover County Building Inspections
City of Wilmington Development Services
Beth,'E. Wetherill, New Hanover County Engineering
Linda' Lewis
Wilmington-Regional:Office
Central Files
North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone [phone] Customer Service 1.877-623-6748
Wilmington Regional Office. Wilmington, NC 28405-3845 FAX [phone] Internet: h2o.enr.state.nc.us One
An Equal OpportunitylAffirmative Action Employer — 50% Recycled110% Post Consumer Paper Nort turn ly
�Urrtura!!y

State Stormwater Management Systems
Permit No. S_W8 permit#
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
The City of Wilmington, NC
Wilmington Police Headquarters
615 Bess Street, New Hanover County
FOR THE
construction, operation and maintenance of a wet 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 October 1, 2014, and shall
be subject to the following specified conditions and limitations:
1. 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 in Section 1.6 on page 3 of this permit. The stormwater
control has been designed to handle the runoff from 250,000 square feet of
impervious area.
3. The tract will be limited to the amount of built -upon area indicated on page 3 of
this permit, and per approved plans.
4. All stormwater collection and treatment systems most 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.
5. The runoff from all built -upon area within the permitted drainage area of this
project must be directed into the permitted stormwater control system.
6. The following design criteria have been provided in the wet detention pond and
Page 2 of 7

State Stormwater Management Systems
Permit No. SW8 permit#
must be;maintained at design condition:
a.
Drainage Area, acres:
7.92
Onsite, ft :
349,309
Offsite, ft2:
0
b.
Total Impervious Surfaces, ft2:.
250,000
C.
Design Storm, inches:
1.0
d.
Pond Depth, feet:
7.5
e.
TSS removal efficiency:
90%
f.
Permanent Pool Elevation, FMSL:
14.6
g.
Permanent Pool Surface Area, ft2:
8,580
h.
Permitted Storage Volume, ft3: .
20,593
i.
Temporary Storage Elevation, FMSL:
16.6
j.
Controlling Orifice:
2"0 pipe
k.
Permitted Forebay Volume, ft3:
3,455
I.
Receiving Stream/River Basin:
Smith Creek 1 Cape Fear
M.
Stream Index Number:
CPF17 18-74-63
n.
Classification of Water Body:.
"C Sw"
II. SCHEDULE OF COMPLIANCE
1. The stormwater management system shall be constructed in its entirety,
vegetated and operational for its intended use prior to the construction of any
built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of
the syste-m 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 slopes and the vegetated filter.
d. Immediate repair of eroded areas.
e. Maintenance of all slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of outlet structure, orifice device, flow
spreader, catch basins and piping.
g. Access to the outlet structure must be available at all times.
4. Records�of maintenance activities must be kept and made available upon
Page 3 of 7

State Stormwater Management Systems
Permit No. SW8_permit#
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 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 failing water from the fountain must be centered in the pond, away
from the shoreline.
d. The maximum horsepower for a fountain in this pond is 1/8 horsepower.
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. A
modification may be required for those deviations.
8. 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.
9. Access to the stormwater facilities shall be maintained via appropriate
easements at all times.
10. 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 any item shown on the approved plans, including the
stormwater management measures, built -upon area, details, etc.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area or to the
drainage area.
e. Farther subdivision, acquisition, lease or sale of 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.
11. The permittee shall submit final site layout and grading plans for any permitted
future areas shown on the approved plans, prior to construction.
12. 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.
13. The Director may notify the permittee when the permitted site does not meet one
Page 4 of 7

State Stormwater Management Systems
Permit No. SW8 permit#
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.
Ill. GENERAL CONDITIONS
1. This permit is not transferable except, after notice to and approval by the Director.
In the event of a change of ownership, or a name change, the permittee must
submit aformal permit transfer request to the Division of Water Quality,
accompanied by a completed name/ownership change form, 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. The permittee is responsible for compliance with all permit
conditions until such time as the Division approves the transfer request.
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) having 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 during normal
busines$'� hours 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.
7. Unless specified elsewhere, permanent seeding requirements for the stormwater
control must follow the guidelines established in the North Carolina Erosion and
Sediment Control Planning and Design Manual.
8. Approved plans and specifications for this project are incorporated by reference
and are enforceable parts of the permit.
9. The permittee shall notify the Division any name, ownership or mailing address
changes';,within 30 days.
Permit issued this the 1 st day of October 2004.
NQRTWCAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Alan W.-,Klimek, P.E., Director
-'-'� Division of Water Quality
By Authority of the Environmental Management Commission
Wilmington Police Headquarters
Page 5 of 7

State Stormwater Management Systems
Permit No. SW$ Lermit#
Stormwater Permit No. SW8 040916
New Hanover Count
Designer's Cehification
I, , as a duly registered
in the State of North Carolina, having been authorized to observe (periodically/ weekly/
full time) the construction of the project,
(Project)
for (Project Owner) hereby state that, to the
best of my abilities, due care and diligence was used in the observation of the project
construction such that the construction was observed to be built within substantial
compliance and intent of the approved plans and specifications.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
SEAT_
Signature
Registration Number
Date
I
Certification Requirements:
Page 6 of 7

State Stormwater Management Systems
Permit No. SWBpermit#
.1. The drainage area to the system contains approximately the permitted
acreage.
2. The drainage area to the system contains no more than the permitted
amount of built -upon area.
3. All the built -upon area associated with the project is graded such that the
runoff drains to the system.
4. All roof drains are located such that the runoff is directed into the system.
5. The outlet/bypass structure elevations are per the approved plan.
6. The outlet structure is located per the approved plans.
7. Trash rack is provided on the outlet/bypass structure.
8. All slopes are grassed with permanent vegetation.
9. Vegetated slopes are no steeper than 3:1.
10. The inlets are located per the approved plans and do not cause short-
circuiting of the system.
11. The permitted amounts of surface area and/or volume have been
provided.
12. Required drawdown devices are correctly sized per the approved plans.
13. All required design depths are provided.
�14. All required parts of the system are provided, such as a vegetated shelf,
and a forebay.
15. The required system dimensions are provided per the approved plans.
cc: NCDENR-DWQ Regional Office
Tony Roberts, New Hanover County Building Inspections
r
Page 7of7

OFFICE USE ONLY
Date Received
Fee Paid
Permit Number
30d-004-
!?S 1-9- s oo,oc,
S Q
State of North Carolina
Department of Environmental and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
City of Wilmington
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
Sterling Cheatham — City Manager
3. Mailing Address for person listed in Item 2 above:
P.O. Box 1810
City: Wilmington State: NC Zip: 28402
Telephone Number: [phone]
4. Project Name (subdivision, facility, or establishment name should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Wilmington Police Headquarters
5. Location of Project (street address):
615 Bess Street
City: Wilmington County: New Hanover
6. Directions to project (from nearest major intersection):
US 17 S. (Market St) to N. 3rd St. Turn right on N 3rd Street, right on Cornelius Harnette Drive, right on
Howard Street, left on N. 61h St, and right on Bess Street. Project is located at 615 Bess Street.
7. Latitude: 340-15' Longitude:
8. Contact person who can answer questions about the project:
77°-57'
of project.
Name: Mark N. Hargrove Telephone Number: [phone]
II. PERMIT INFORMATION:
I. Specify whether project is (check one): X - New Renewal Modification
Form SWU-101 Version 3.99 Pagel of4

2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number and its issue date (if known)
3. Specify the type of project (check one):
Low Density X High Density Redevelop General Permit Other
4. Additional Project Requirements (check applicable blanks):
CAMA Major X Sedimentation/Erosion Control 404/401 Permit NPDES Stormwater
Information on required state permits can be obtained by contacting the Customer Service Center at
1-877-623-6748
III. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative
(one to two pages) describing stormwater management for the project.
The stormwater runoff will be treated by the a proposed detention pond sized to for removal of
90% of TSS.
2. Stormwater runoff from this project drains to the Cape pear River Basin.
3. Total Project Area: 7.92 acres.
4. Project Built Upon Area: 72.5 %.
5. How many drainage areas does the project have? 1
6. Complete the following information for each drainage area. If there are more than two drainage areas in the
project, attach and additional sheet with the information for each area provided in the same format as below.
Basin Information
Drainage Area I
Drainage Area 2
Receiving Stream Name
Smith Creels
Receiving Stream Class
C; Sw
Drainage Area
349,309 sf
Existing Impervious*Area
0
Proposed Impervious* Area
250,000 sf
% Impervious*_ Area (Total)
71.6%
Impervious* Surface Area
Drainage Area I
Drainage Area 2
On -Site Buildings
54,000 sf
On -Site Streets
0 sf
On -Site Parking....173,594
sf
On -Site Sidewalks
15,506 sf
Other On -Site (walls mesh. ard)
6,900 sf
Off -Site
0
Total: 250,000 sf
Total:
See attachment 1 for impervious calculation analysis
FormSWU-101 Version 3.99 Page 2 of

*Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
7. How was the off -site impervious area listed above derived?
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
The following italicized deed restrictions and protective covenants are required to be recorded for all
subdivisions, out parcels, and future development prior to the sale of any lot. If lot sizes vary significantly, a
table listing each lot number, size, and the allowable built -upon area for each lot must be provided as an
attachment.
The following covenants are intended to ensure ongoing compliance with state stortnwater management
permit number as issued by the Division of Water Quality. These covenants may not
be changed or deleted without the consent of the State.
2. No more than 250,000 square feet of any lot shall be covered by structures or impervious materials.
Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but not include
wood decking or the water surface of swimming pools.
3. Swales shall not be f lled in, piped, or altered except as necessary to provide driveway crossings.
4. Built -upon area in excess of the permitted amount requires a state stortnwater management permit
modification prior to construction.
5. All permitted runofffrom the outparcels orfirture development shall be directed into the permitted
stormwater control system. These connections to the stortnwater control system shall be performed in a
manner that maintains the integrity and performance of the system as permitted.
By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
shall include all the applicable items required above, 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 State, and that they will be recorded prior to the sale of any lot.
V. SUPPLEMENT FORNIS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for
each BMP specified for this project. Contact the Stormwater and General Permits Unit at [phone] for
the status and availability of these forms.
Form SWU-102
Wet Detention Basin Supplement
Form SWU-103
Infiltration Basin Supplement
Form SWU-104
Low Density Supplement
Form SWU-105
Curb Outlet System Supplement
Form SWU-106
Off -Site System Supplement
Form SWU-107
Underground Infiltration Trench Supplement
Form SWU-108
Neuse River Basin Supplement
Form SWU-109
Innovative Best Management Practice Supplement
Form SWU-101 Version 3.99 Page 3 of 4

VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ)_ A
complete package includes all of the items listed below. The complete application package should be submitted to
the appropriate DWQ Regional Office.
1. Please indicate that you have provided the following required information by initialing in the space provided
next to each item.
Initials
• Original and one copy of the Stormwater Management Permit Application Form InA)A
• One copy of the applicable Supplement Form(s) for each $MP /A, J#
• Permit application processing fee of $4-2ft{payable to NCDENR) yobv /r N 14
• Detailed narrative description of stormwater treatment/management 0v1 4
• Two copies of plans and specifications, including: ih N
- Development/ Project name
- Engineer and firm
-Legend
- North arrow
- Scale
- Revision number & date
- Mean high water line
- Dimensioned property/project boundary
- Location map with named streets or NCSR numbers
- Original contours, proposed contours, spot elevations, finished floor elevations
- Details of roads, drainage features, collection systems, and stormwater control measures
- Wetlands delineated, or a note on plans that none exist
- Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations
- Drainage areas delineated
- Vegetated buffers (where required)
VII. AGENT AUTHORIZATION
If you wish to designate authority to another individual or firm so that they may provide information on your
behalf, please complete this section.
Designated agent (individual or firm): W. K. Dickson & Co., Inc.
Mailing Address: 909 Market Street
City Wilmington
Phone: [phone]
State: NC
VIIL APPLICANT'S CERTIFICATION
Zip: 28401
Fax: [phone]
1, (print or tyke name of person listed in General Information, Item 2) Sterling Cheatham
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 15A
NCAC 2H.1000.
Signature: Date:
Form SWU-101 Version 3.99 Page 4 of 4

Permit No,
(to be provided by DWQ)
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form may be photocopied for use as an original
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for
each basin, design calculations, and plans and specifications showing all basin and outlet structure details.
1. PROJECT INFORMATION
Project Name: Wilmington Police
Contact Person: Mark Hargrove, P.E. Phone Number: 7624200 x250
For projects with multiple basins, specify which basin this worksheet applies to: NA, single basin
elevations
Basin Bottom Elevation
Permanent Pool Elevation
Temporary Pool Elevation
areas
Permanent Pool Surface Area
Drainage Area
Impervious Area
voluntes
Permanent Pool Volume
Temporary Pool Volume
Forebay Volume
other parameters
SA/DA'
Diameter of Orifice
Design Rainfall
Design TSS Removal
Footnotes:
7.1
14.6
16.6
8,580
8.01
5.74
ft. (door of the basin)
ft. (elevation of the orifice)
ft. (elevation of the discharge structure overflow)
sq. ft. (water surface area at the orifice elevation)
ac. (on -site and off -site drainage to the basin)
ac. (on -site and off site drainage to the basin)
19,841
cu. ft.
20,593
cu. ft.
3,455
cu. ft.
2.38
2
in.
1.0
in.
90
%
(combined volume of main basin and forebay)
(volume detained above the permanent pool)
(approximately 20% of total volume)
(surface area to drainage area ratio frwn, DWQ table)
(2 to 5 day temporary pool draw -down required)
(minimum 85% required)
When using the Division SAIDA tables, the correct SAIDA ratio for permanent pool sizing should be computed based
upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the
correct value for nonstandard table entries.
In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to
provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90%
TSS removal.
Form SWU-102 Rev 3.99 Page 1 of 4

II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C.
Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A
NCAC 2H. 1008.
Initial in the space provided to indicate the following design requirements have been met and supporting documentation is
attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may
initial below. If a requirement has not been met, attach justification.
Applicants Initials
a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). Po od 5
A NO__ b. The forebay volume is approximately equal to 20% of the basin volume.
MA- c. The temporary pool controls runoff from the design storm event.
/F'.1 hL d. The temporary pool draws down in 2 to 5 days.
e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow calculations)
AN f. The basin length to width ratio is greater than 3: 1.
MAug g. The basin side slopes above the permanent pool are no steeper than 3: 1.
it 99 h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail).
M N- i. Vegetative cover above the permanent pool elevation is specified.
j. A trash rack or similar device is provided for both the overflow and orifice.
k. A recorded drainage easement is provided for each basin including access to nearest right-of-way.
N 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is
specified prior to use as a wet detention basin.
m. A mechanism is specified wh'ch will drain the basin 1for maintenance or an emergency.
po+�.�[ w'.11 b� pomye7 ofawjA ror` nlaf►t1tA.4nGe- ot, a, fn&eoppnGY
III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated
filter if one is provided.
This system (check one) 0 does X does not incorporate a vegetated filter at the outlet.
This system (check one) 0 does X does not incorporate pretreatment other than a forebay.
form SWU-102 Rev 3.99 Page 2 of 4

Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated
cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2
to 5 days as designed.
2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover
to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper
functioning.
4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to
75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate
manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet
detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth
reading and not readily penetrate into accumulated sediments.
When the permanent pool depth reads 5,61 feet in the main pond, the sediment shall be removed.
When the permanent pool depth reads 3,0 feet in the forebay, the sediment shall be removed.
Sediment
Bottom
El. I/, 6
i" /0'b----
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 1 , L
711,
Sediment Removal Elevation75%a -------------------------------------- _-----f25%
---
Bottom Elevation �• �
FOREBAY MAIN POND.
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet detention basin system shall be maintained in good working order.
Form SWU-102 Rev 3.99 Page 3 of 4

I acknowledge and agree by my signature below that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any
changes to the system or responsible party.
Print name: Sterling Cheatham
Title: City Manager
Address: P.O. Box 1810 / Wilmington NC, 28402
Phone: [phone]
Date: q~ 7— 0
Signature: I�
Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots
have been sold and a resident of the subdivision has been named the president.
I, C Zfe-40A a Notary Public for the State of IUp
County of cz _ do hereby certify that-��w1,r,Q ,8,
personally appeared before me this A ? day of Si,D�e �,� and acknowledge the due
execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal,
g. F:. •.:
_ .. oo0
'p U.D'U1'f';'t�';i
� .j�Ctt C0%)e'3 �^ .
SEAL
My commission expires / p /G la
Form SWU-102 Rev 399 Page 4 of