SW7090221_CURRENT PERMIT_20090313

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW_0�
DOC TYPE
[CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD

NC®ENR
North Carolina Department of Environment and Natural Resources
Beverly Eaves Perdue
Governor
Mr. Erik Christofferson, Division Chief
NC Wildlife Resources Commission
NCSU Centennial Campus
1751 Varsity Drive
Raleigh, NC 27606
Dear Mr. Christofferson:
Division of Water Quality
Coleen H. Sullins
Director
March 13, 2009
Subject: Stormwater Permit No. SW7090221
Chowan River Bridge Site Improvements
High Density Project
Chowan County
Dee Freeman
Secretary
The Washington Regional Office received a complete Stormwater Management Permit Application for
Chowan River Bridge Site Improvements on March 6, 2009. 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. We are forwarding Permit No. SW7090221 dated
March 13, 2009, for the construction of the subject project.
This permit shall be effective from the date of issuance until March 13, 2019, 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 150E of the
North Carolina General Statutes, and filed with the Office of Administrative Hearings, 6714 Mail
Service Center, Raleigh, NC 27699-6714. 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 Scott
Vinson, or me at [phone].
4incerely
AI od e ob6
Regional Supervisor
Surface Water Protection Section
AH/sv: S:\WQS\STORMWATER\PERMIT\SW7090221
cc: Stephen Janowski, PE
Chowan County Building Inspections
David Moye, Division of Coastal Management
Washington Regional Office
Central Files
North Carolina Division of Water Quality Internet: v .ncwaterquality.org One
943 Washington Square Mall Phone: [phone] FAX: [phone] NortYtCarolina
Washington, NC 27889 FAX: [phone] //
An Equal Opportunity 1 AffrmaGve Action Employer Naturally

State Stormwater Management Systems
Permit No. SW7090221
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
NC Wildlife Resources Commission
Chowan River Bridge Site Improvements
Chowan 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 March 13, 2019, 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 in Section 1.6 on page 3 of this permit. The stormwater
control has been designed to handle the runoff from 69,916 square feet of
impervious area which consists of 57,416 square feet of existing 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. The built -upon area for the development not
draining to the wet detention basin is limited to 4,792 square feet.
4. 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.
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.
Page 2 of 7

State Stormwater Management Systems.
Permit No. SW7090221
6. The following design criteria have been provided in the wet detention pond and
must be maintained at design condition:
a. Drainage Area, ft2:
b. Total Impervious Surfaces, ft2:
C. Design Storm, inches:
d. Pond Depth, feet:
e. TSS removal efficiency:
f. Permanent Pool Elevation, FMSL:
g. Permanent Pool Surface Area, ft2:
h. Permitted Storage Volume, ft3:
i. Temporary Storage Elevation, FMSL:
j. Controlling Orifice:
k. Permitted Forebay Volume, ft3:
I. Receiving Stream/River Basin:
M. Stream Index Number:
n. Classification of Water Body
II. SCHEDULE OF COMPLIANCE
104,108
69,916
1.50
3.0
90%
2.00
8,607
10,297
3.00
1.50"0 pipe
3,519
Chowan River / Pasquotank
25
"B; NSW"
1. The stormwater management system shall be constructed in its entirety,
vegetated and operational for its intended use prior to the construction of any
built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of
the system will be repaired immediately.
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:
12
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.
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.
Page 3 of 7

State Stormwater Management Systems
Permit No. SV 7090221
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. 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. Further 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 at all times.
13. 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 minimy,mtyeq;uirements. The permittee
shall provide copies of revised plans and certificatiori'i'n writing to the Director
that the changes have been made.
Page 4 of 7

State Stormwater Management Systems.
Permit No. SV 7090221
III. GENERAL CONDITIONS
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 a formal 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
business 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.
10. This permit shall be effective from the date of issuance until March 13, 2019.
Application for permit renewal shall be submitted 180 days prior to the expiration
date of this permit and must be accompanied by the processing fee.
Permit issued this the 13th day of March, 2009.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
Oi iginal Signed by
Al Hodge for
Coleen H. Sullins, Director
Division of Water Quality
By Authority of the Environmental Management Commission
Permit No. SW7090221
Page 5 of 7

State Stormwater Management Systems
Permit No. SVV7090221
Chowan River Bridge Site Improvements
Stormwater Permit No. SV 7090221
Chowan County
Designer's Certification
I, , as a duly registered
in the State of North Carolina, having been authorized to observe (periodically/ weekly/
full time) the construction of the project,
(Project)
for (Project Owner) hereby state that, to the
best of my abilities, due care and diligence was used in the observation of the project
construction such that the construction was observed to be built within substantial
compliance and intent of the approved plans and specifications.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
Page 6 of 7

State Stormwater Management Systems.
Permit No. SW7090221
Certification Requirements:
1. The drainage area to the system contains approximately the permitted
acreage.
2. The drainage area to the system contains no more than the permitted
amount of built -upon area.
3. All the built -upon area associated with the project is graded such that the
runoff drains to the system.
4. All 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
Chowan County Building Inspections
Page 7 of 7

Designer's Certification
l if%4ea s uIy registered
in the State of North Carolina, having been authorized to observe is weekly/
full time) the construction of the project,
(Project) WV
for / I./ 1/� / / " (Project Owner) hereby state that, to the
best of my abilities, due care and iligence 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:
SEAL
N�' HRo�'°�-
�P .oFEss,oti
SEAL
UC. I t2324 � X
Page 6 of 7

Vkaka vlul I l IWO= IVIaI lagvi I ICI II JySICII IS
Permit N
Certification Requirements:
cc:
The drainage area to the system contains approximately the permitted
acreage.
The drainage area to the system contains no more than the permitted
amount of built -upon area.
All the built -upon area associated with the project is graded such that the
runoff drains to the system.
All roof drains are located such that the runoff is directed into the system.
The outlet/bypass structure elevations are per the approved plan.
The outlet structure is located per the approved plans.
Trash rack is provided on the outlet/bypass structure.
All slopes are grassed with permanent vegetation.
Vegetated slopes are no steeper than 3:1.
The inlets are located per the approved plans and do not cause short-
circuiting of the system.
The permitted amounts of surface area and/or volume have been
provided.
Required drawdown devices are correctly sized per the approved plans.
All required design depths are provided.
All required parts of the system are provided, such as a vegetated shelf,
and a forebay.
The required system dimensions are provided per the approved plans.
NCDENR-DWQ Regional Office
Beaufort County Building Inspections
Page 7 of 7

State of North Carolina
FEB 2 6 2009 Department of Environment and Natural Resources
NC DENR Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
1. GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
NC Wildlife Resources Commission
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
Erik Christofferson Division Chief
3. Mailing Address for person listed in item 2 above:
NCSU Centennial Campus 1751 Varsity Drive
City: Raleigh State: NC Zip: 27606
Phone: (919 ) 707-0010 Fax:
Email:
4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Chowan River Bridge Site Improvements
5. Location of Project (street address):
248 Wildlife Access Road
City: Edenton County:Chowan Zip: 27932
6. Directions to project (from nearest major intersection):
From the intersection of Highway 32 and Highway 17 in Edenton head west on Highway 17 for 3.33 miles
Project site is located at eastern end of Chowan River Bridge just north of Highway 17
7. Latitude 360 03' 18" N Longitude: 76' 41' 00" W of project
8. Contact person who can answer questions about the project:
Name: 1. Stephen Janowski P E Telephone Number: (252 1 756-1390
Eiiiail:[e-mail]
If. PERMIT INFORMATION:
1. Specify whether project is (check one): ®New ❑Renewal ❑Modification
FOI'm SWU-101 Version 09.25.08 Page I of

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
3. Specify the type of project (check one):
❑Low Density ❑I-ligh Density ®Redevelop ❑General Permit ❑Universal SMP []Other
4. Additional Project Requirements (check applicable blanks; information on required state permits can be
obtained by contacting the Customer Service Center at 1-877-623-6748):
®CAMA Major ®Sedimentation/Erosion Control ❑404/401 Permit ❑NPDES Industrial Stormwater
Ill. 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.
Stormwater runoff from the proposed parking lot will be collected by two drop inlets and piped to a wet
detention pond, which is designed to remove 90% TSS.
2. Stormwater runoff from this project drains to the Chowan River basin.
3. Total Property Area: 4.056 acres 4. Total Coastal Wetlands Area: 0.0 acres
5. Total Property Area (3) - Total Coastal Wetlands Area (4) = Total Project Area**: 4.056 acres
6. (Total Impervious Area / Total Project Area) X 100
7. How many drainage areas does the project have?2
Project Built Upon Area (BUA): 42.28
8. Complete the following information for each drainage area. If there are more than two drainage areas in the
project, attach an additional sheet with the information for each area provided in the same format as below.
For high density projects, complete the table with one drainage area for each engineered stormwater device.
Basin information
,- Drainage; Area 1.
Drainage_Aiea 2,-
Receiving Stream Name
Chowan River
Chowan River
Stream Class & Index No.
B; NSW, 25
B: NSW, 25
Total Drainage Area (sf)
104,108
72571
On -site Drainage Area (so
104,108
72571
Off -site Drainage Area (so
0
0
Existing Impervious* Area (so
57,416
0
Proposed Impervious*Area (so
69,916
4,792
% Impervious* Area (total)
67.16%
6.60%
Impervious* Surface Area
Drainage Area 1
Draihage Area 2
On -site Buildings (so
858
0
On -site Streets (so
0
0
On -site Parking (sf)
67,827
4,792
On -site Sidewalks (so
1,231
0
Other on -site (so
0
0
Off -site (sf)
0
0
Total (so:
69,916
4,792
* Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
**Total project area shall be calculated to exclude Coastal Wetlands from use when calculating the built upon area
percentage calculation. This is the area used to calculate overall percent project built upon area (BUA).
Form SWU-101 Version 09.25.08 Page 2 of 4

9. How was the off -site impervious area listed above derived
Projects in Union County: Contact the DWQ Central Office staff to check to see ifyou project is located
within it Threatened & Endangered Species watershed that may be subject to more stringent stormwater
requirements.
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
One of the following property restrictions and protective covenants are required to be recorded for all
subdivisions, outparcels 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.
Forms can be downloaded from httl2://l12o.enr.state.iic.us/su/bnip forms htm - deed restrictions.
Form DRPC-1
High Density Commercial Subdivisions
Form DRPC-2
High Density Developments with Outparcels
Form DRPC-3
High Density Residential Subdivisions
Form DRPC-4
Low Density Commercial Subdivisions
Form DRPC-5
Low Density Residential Subdivisions
Form DRPC-6
Low Density Residential Subdivisions with Curb Outlets
By your signature below, you certify that the recorded property restrictions and protective covenants for this
project shall include all the applicable items required in the above form, 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 DWQ and that they will be recorded prior to
the sale of any lot.
V. SUPPLEMENT FORMS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for each
BMP specified for this project. Contact the Stormwater Permitting Unit at [phone] for the status and
availability of these forms. Forms can be downloaded from http://h2o.enr.state.iic.us/su/bnil2 forms.htm.
Form SW401-Low Density
Form SW401-Curb Outlet System
Form SW401-Off-Site System
Form SW401-Wet Detention Basin
Form SW401-Infiltration Basin
Form SW401-Infiltration Trench
Form SW401-Bioretention Cell
Form SW401-1-evel Spreader
Form SW401-Wetland
Form SW401-Grassed Swale
Form SW401-Sand Filter
Form SW401-Permeable Pavement
Form SW401-Cistern
Low Density Supplement
Curb Outlet System Supplement
Off -Site System Supplement
Wet Detention Basin Supplement
Infiltration Basin Supplement
Underground Infiltration Trench Supplement
Bioretention Cell Supplement
Level Spreader/Filter Strip/Restored Riparian Buffer Supplement
Constructed Wetland Supplement
Grassed Swale Supplement
Sand Filter Supplement
Permeable Pavement Supplement
Cistern Supplement
Form SWU-101 Version 09.25.08 Page 3 of

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 Office. (Appropriate office may be found by locating project on the
interactive online map at httoi/fh2o enr state nc us/sufmsi mans htm)
1. Please indicate that you have provided the following required information by initialing in the space provided
next to each item. I
• Original and one copy of the Stormwater Management Permit Application Form
• Original and one copy of the Deed Restrictions & Protective Covenants Form (if
required as per Part IV above)
• Original of the applicable Supplement Form(s) of O&M agreement(s) for each BMP
• Permit application processing fee of $505 (Express: $4,000 for HD, $2,000 for LD)
payable to NCDENR
• Calculations & detailed narrative description of stormwater treatment/management
• Copy of any applicable soils report
• Two copies of plans and specifications (sealed, signed & dated), including;
- 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 (such as additional information requests), please complete this section. (ex. designing engineer or firm)
Designated agent (individual or firm):Baldwin and Tanowski PA
Mailing Address:1015 Conference Drive
City:Greenvil(e State:NC Zip:27M
Phone: [phone] Fax: [phone]
Email:[e-mail] -
Vlll. APPLICANTS CERTIFICATION
1, (print or type mare of person listed in General btformation, item 2) Erik Clrristofferson Division Chief
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: v / ��""(,C(/ Date: a o� �� O
Ci
Form SW U-101 Version 09.25.08 Page 4 of 4

Permit No.
(to be pmvidetl by OWO)
OF WA749
TA
O� �G
y �
NCDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form most be filled out, printed and submitted.
The Required Items Checklist (Pad 111) must be printed, filled out and submitted along with all of the required information.
Project name
Contact person
Phone number
Date
Drainage area number
919-707-0010
2/20/2009
1
CHOWAN RIVER BRIDGE SITE IMPROVEMENTS
ERIK CHRISTOFFERSON
II.',DESIGN,INFORMATION:p.,
r°3 e,
Site Characteristics
Drainage area
104,108 ft'
Impervious area, post -development
69,916 ft'
% impervious
67.16 %
Design rainfall depth
1.5 in
Storage Volume: Non -SA Waters
Minimum volume required
8,517 ft'
OK
Volume provided
10,297 ft3
OK, volume provided is equal to or in excess of volume required.
Storage Volume: SA Waters
1.5' runoff volume
it
Pre -development 1-yr, 24-hr runoff
ft3
Post -development 1-yr. 24-hr runoff
it,
Minimum volume required
0 0
Volume provided it
Peak Flow Calculations
Is the pre/post control of the lyr 24hr storm peak flow required?
Y (Y or N)
1-yr, 24-hr rainfall depth
4.0 in
Rational C, pre -development
0.55 (unidess)
Rational C, post -development
0.59 (unitless)
Rainfall intensity:l-yr, 24-hr storm
6.40 inthr OK
Pre -development 1-yr, 24-hr peak flow
8.98 ft/sec
Post -development 1-yr, 24-hr peak flow
5.04 ft3lsec
Pre/Post 1-yr, 24-hr peak flow control
-3.94 ft3lsec
Elevations
Temporary pool elevation
3.00 fmsl
Permanent pool elevation
2.00 frost
SHWT elevation (approx. at the pen. pool elevation)
2.00 final
Top of 10ft vegetated shelf elevation
2.50 fist
Bottom of 1011 vegetated shelf elevation
1.50 frost
Sediment cleanout, top elevation (bottom of pond)
-2.00 fmsl
Sediment cleanout, bottom elevation
-3.00 first
Sediment storage provided
1.00 ft
Is there additional volume stored above the state -required temp. pool?
Y (Y or N)
Elevation of the top of the additional volume
3.0 lost OK
Form SW401-Wet Detention Basin-Rev.5 Paris 1.8I1. Design Summary, Page 1 of 2

Permit
(to W provided by DWD)
VDESIGN;INF,ORMATION:.'t v ';�+'; ,d , +....�R,.,�. e..,,._ :xi:: a1. �3i,�:h. Ywsn."«i .��t''....:;:xn ya., tr r.`..,f?;'T...tv.:. ` • 1`:ir,`,.,
Surface Areas
Area, temporary pool
Area REQUIRED, permanent pool
SA/DA ratio
Area PROVIDED, permanent pool, Ap,,,,,
Area, bottom of 10ft vegetated shelf, A. „,t
Area, sediment cleanout, top elevation (bottom of pond), A o,.
Volumes
Volume, temporary pool
Volume, permanent pool, Vp,,,,y.
Volume, forebay (sum of forebays if more than one forebay)
Forebay %of permanent pool volume
SAIDA Table Data
Design TSS removal
Coastal SAIDA Table Used?
Mountain/Piedmont SAIDA Table Used?
SAIDA ratio
Average depth (used in SAIDA table):
Calculation option 1 used? (See Figure 10-2b)
Volume, permanent pool, Vp,,,, .
Area provided, permanent pool, A...
Average depth calculated
Average depth used in SAIDA, d„, (Round to nearest 0.5ft)
Calculation option 2 used? (See Figure 10-21b)
Area provided, permanent pool, A...
Area, bottom of 10ft vegetated shelf, Aw ,,,
Area, sediment cleanout, top elevation (bottom of pond), A.y,q
'Depth" (distance b/w bottom of 1011 shelf and top of sediment)
Average depth calculated
Average depth used in SAIDA, d„, (Round to nearest 0.5ft)
Drawdown Calculations
Drawdown through orifice?
Diameter of orifice (if circular)
Area of orifice (if-noncircular)
Coefficient of discharge (Co)
Driving head (Ho)
Drawdown through weir4
Weir type
Coefficient of discharge (C,)
Length of weir (L)
Driving head (H)
Pre -development 1-yr, 24-hr peak flow
Post -development 1-yr, 24-hr peak flow
Storage volume discharge rate (through discharge orifice or weir)
Storage volume drawdown time
Additional Information
Vegetated side slopes
Vegetated shelf slope
Vegetated shelf width
Length of flowpath to width ratio
Length to width ratio
Trash rack for overflow 8 orifice?
Freeboard provided
Vegetated filter provided?
Recorded drainage easement provided?
Capures all runoff at ultimate build -out?
Drain mechanism for maintenance or emergencies
Form SW401-Wet Detention Basin-Rev.5
11,987 it'
7,288 IF
7.00 (unitless)
8,607 ft' OK
4,382 ft'
1,936 ft'
10,297 rya OK
17,187 ft'
3,519 ft'
20.5% % OK
90 %
Y (Y or N)
N (Y or N)
7.00 (unitless)
N (Y or N)
It
ft'
ft
it
Y (Y or N)
8,607 ft' OK
4,382 It' OK
1,936 rye
OK
3.50 it
OK
2.90 it
OK
3.0 it
OK
Y (Y or N)
1.50 in
in'
0.60 (unitless)
0.33 it
N (Y or N)
(unitless)
(unitless)
If
It
8.98 fts/sec OK
5.04 fts/sec OK
0.03 fts/sec
3.51 days
OK, draws down in 2-5 days.
OK, dmwdown time is connect.
OK
OK
OK
OK
OK
OK
OK
N (Y or N) OK
Y (Y or N) OK
Y (Y or N) OK
EMERGENCY SPILLWAY
3 :1
10 :1
10.0 ft
3 :1
1.5 :1
Y (Y or N)
1.0 ft
Parts I. 8 II. Design Summary, Page 2 of 2

Permit No.
0 bd provided by DWp)
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result to a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
Indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Page/ Plan
Shget�o
1. Plans 0' - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Basin dimensions,
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
2. Partial plan (1' = Nor larger) and details for the wet detention basin showing:
- Outlet structure with trash rack or similar,
- Maintenance access,
- Permanent pool dimensions,
- Forebay and main pond with hardened emergency spillway,
- Basin cross-section,
- Vegetation spe liication for planting shelf, and
- Filter strip,
3. Section view of the wet detention basin (1' = 20' or larger) shoving:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified
on the plans prior to use as a wet detention basin.
5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
to verify volume provided.
6. A construction sequence that shows how the wet detention basin will be protected from sediment until the
entire drainage area is stabilized.
7. The supporting calculations.
8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
9. A copy of the deed restrictions (if required).
10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Wel Detention BasinRev.5 Pad III. Required Items Checklist, Page 1 of 1

Permit Number:
(to be provided by DWQ)
Drainage Area Number.
Wet Detention Basin Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
The 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):
❑ dons ® does not incorporate a vegetated filter at the outlet.
This system (check one):
❑ does ® does not incorporate pretreatment other than a forebay.
Important maintenance procedures:
— Immediately after the wet detention basin is established, the plants on the
vegetated shelf and perimeter of the basin should be watered twice weekly if
needed, until the plants become established (commonly six weeks).
— No portion of the wet detention pond should be fertilized after the first initial
fertilization that is required to establish the plants on the vegetated shelf.
— Stable groundcover should be maintained in the drainage area to reduce the
sediment load to the wet detention basin:
— If the basin must be drained for an emergency or to perform maintenance, the
flushing of sediment through the emergency drain should be minimized to the
maximum extent practical.
— Once a year, a dam safety expert should inspect the embankment.
After the wet detention pond is established, it should be inspected once a month and
within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a
Coastal County). Records of operation and maintenance should be kept in a known set
location and must be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
Potential problem:
How I will remediate the problem:
The entire BMP
Tras debris is resent.
Remove the trash debris.
The perimeter of the wet
detention basin
of bare soil and/or
erosive gullies have formed.
Regrade the soil if necessary to
remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Vegetation is too short or too
long. I
Maintain vegetation at a height of
approximately six inches.
Form SW401-Wet Detention Basin O&M-Rev.4
Page 1 of 4,

Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged.
Unclog the pipe. Dispose of the
swale
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged.
Erosion is occurring in the
Regrade the swale if necessary to
swale.
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
The forebay
Sediment has accumulated to
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design depth for
possible. Remove the sediment and
sediment storage.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Erosion has occurred.
Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
Weeds are present.
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
The vegetated shelf
Best professional practices
Prune according to best professional
show that pruning is needed
practices
to maintain optimal plant
health. .
Plants are dead, diseased or
Determine the source of the
dying.
problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Weeds are present
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
The main treatment area
Sediment has accumulated to
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design sediment
possible. Remove the sediment and
storage depth.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Algal growth covers over
Consult a professional to remove
50% of the area.
and control the algal growth.
Cattails, phragmites or other
Remove the plants by wiping them
invasive plants cover 50% of
with pesticide (do not spray).
the basin surface.
Form SW401-Wet Detention Basin O&M-Rev.4 Page 2 Of 4

Permit Number:
fto be provided by DWQ)
Drainage Area Number:
BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
Shrubs have started to grow
Remove shrubs immediately.
on the embankment.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present
consult a professional to remove
beavers.
A tree has started to grow on
Consult a dam safety specialist to
the embankment.
remove the tree.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair. if applicable)
The outlet device
Clogging has occurred.
Clean out the outlet device. Dispose
of the sediment off -site.
The outlet device is dama ed
Repair or replace the outlet device.
The receiving water
Erosion or other signs of
Contact the local NC Division of
damage have occurred at the
Water Quality Regional Office, or
outlet
the 401 Oversight Unit at 919-733-
1786.
The measuring device used to determine the sediment elevation shall be such
that it will give an accurate depth reading and not readily penetrate into
accumulated sediments.
When the permanent pool depth reads 4.00 feet in the main pond, the
sediment shall be removed.
When the permanent pool depth reads 2.50 feet in the forebay, the sediment
shall be removed.
Sediment Removal
Bottom
BASIN DIAGRAM
. (11I1 in the blanks)
Permanent Pool Elevation 2.00
-Q„S5 1rPeneri�pool------------- ume Sediment Removal Elevation -2_00 volume
-1_50in. -------------------------
ement Bottom Elevation -3.00 I I-ft n
Storage Sedimer
Storage
FOREBAY MAIN POND
Form SW401-Wet Detention Basin O&M-Rev.4 Page 3 of 4

Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project nameChowan River Bridge Site Improvements
BMP drainage area
Print name:Erik Christofferson
Title:Division Chief
Address:NCSU Centennial Campus 1751 Varsity Drive
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, La N\ 1a_A. 1. �rA \,� aa( 14 a Notary Public for the State of
off L, -L
&r ' County of W &L , do hereby certify that
3TC'i `F e _ o�CLC Soi.. personally appeared before me this
day of /ILL - \ax 1' OOi , and acknowledge the due execution of the
forgoing wet detention basin maintenance requirements. Witness my hand and official
seal,
Notary Public
Wake county
North Caroling
SEAL
My commission expires of a 6 - oio 11
Form S W401-Wet Detention Basin O&M-Rev.4 Page 4 of 4