SW7080205_HISTORICAL FILE_20210629

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW_%)'IJD�
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ .COMPLIANCE EVALUATION INSPECTION
DOC DATE(f��(p
YYYYMMDD

ROY COOPER
Governor
JOHN NICHOLSON
interim Secretary
BRIAN WRENN
Director
Pasquotank County
Attention: Sparty Hammett,
206 E. Main Street
Elizabeth City, NC 27909
Dear Mr. Hammett:
NORTH CAROLINA
Environmental Quality
June 29, 2021
County Manager
Subject: Stormwater Permit Renewal
Stormwater Management Permit SW7080205
River Road Soccer Complex
Pasquotank County
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A Division of Energy, Mineral, and Land Resources file review has determined that
Stormwater Permit SV 7080205 for a stormwater treatment system consisting of a wet
detention pond serving the River Road Soccer Complex located at 1701 River Road,
Elizabeth City, NC expires on December 30, 2021. This is a reminder that permit
renewal applications are due 180 days prior to expiration. We do not have a record of
receiving a renewal application.
Please submit a completed permit renewal application along with a $505.00 fee for
permit renewal. Also, it was noted in the file review that a designer's certification that the
project was constructed in accordance with the approved plans as required by the
permit has not been submitted. Please include this with your application. Permit
application forms for renewal can be found on our website at:
https://deq.nc gov/about/divisions/energy-mineral-and-land-
resources/stormwater/stormwater-program/post-construction-2. North Carolina General
Statutes and the Coastal Stormwater rules require that this property be covered under a
stormwater permit.
If you have questions, please feel free to contact me at [phone]. 1 will be glad to
discuss this by phone or meet with you. If you would like, I can e-mail you a copy of the
application forms. You can request a copy by e-mailing me at
roger.thorpe(a)ncdenr.gov.
Sincerely,
i.
Roger K. Thorpe
Environmental Engineer
�< North Carolina Department of Environmental Quality ' Division of Energy, Mineral and Land Resources
1/ Washington Regional Off9re i 943 Washingrnn Square Mall I Washington, North Carolina 27889
m F-D
. ' 000 252.946.64SI

Permit Number SW7080205
Program Category
State SW
Penn it Type
State Stormwater
Primary Reviewer
emest.odei-larbi
Coastal SWRuIe
Coastal Stormwater- 1995
Permitted Flow
Facility
Central Files. APS _ SWP _
11/13/2014
Permit Tracking Slip
Status
Project Type
Active
New Project
Version
Permit Classification
1.00
Individual
Permit Contact Affiliation
Facility Name Major/Minor Region
River Road Soccer Complex Minor Washington
Location Address '-�i County
1701 River Rd GV i�, Lf- � mcpq-- � v Pasquotank
Facility Contact Affiliation
Elizabeth City NC 27907
Owner
Owner Name Owner Type
Pasquotank County Government - County
Owner Affiliation
Randy Keaton
PO Box 39
Dates/Events Elizabeth City NC 27909
Scheduled
Ong Issue App Received Draft Initiated Issuance
Public Notice Issue
Effective Expiration
4/9/2008 2/4/2008
4/9/2008
4/9/2008 12/30/2021
Regulated Activities
Requested /Received Events
State Stormwater - HD - Detention Pond
Deed restriction requested
Deed restriction received
Additional information requested
3120108
Additional information requested
2114108
Additional information received
3112108
Additional information received
417/08
Outfall
Waterbody Name Streamindex Number Current Class Subbasin

River Road Soccer Complex — Detailed Protect Narrative
The proposed project is located just south of River Road Middle School in Elizabeth City, NC.
This project will includerthe construction of 5 (five) new soccer fields, a picnic shelter,
la round; and anew arkiri facilit The existiii school"has 2 two adjoining baseball fields
P Yg parking Y g (two) J g
and a 1-story"bathroom facility to which our proposed trails will connect. The existing ground
surface is relatively flat, with contours ranging from 4.0 to 9.0 ft. There are existing swales that
convey water between the proposed soccer field areas, the existing school, and ball fields. The
majority of the site has a grassy cover and is sporadically populated with pecan trees.
The drainage areas have been broken up into two separate areas that drain to a single location
that is on the North side of the project between the existing ball fields and the proposed soccer
fields. This project would typically fall under a low -density condition, however the parking lot
and driveway makes this project have a "pocket" of high density. The two -areas 7were delineated
based on the principal of the pocket of high -density improvements. Area 1-consists of th'e five
soccer fields, connecting grass areas, and the playground. This area's runoff coefficient changed
from 0.32 to 0.35 resulting in minimal increase in flows. The storm conveyance calculations use
the rational method and a storm design frequency of 5-years. This frequency is mandated by the
City of Elizabeth City's Unified Development Ordinance (UDO) for areas draining les`s tha i_75
acres.
Area 2 contains the majority of the impervious areas (parking and driveways) for this site. This
area will be treated and detained using a wet detention basin. This wet detention basin is
designed using the most current NCDENR standards for the "90 percent TSS Pollutant Removal
Efficiency in the Coastal Region". This wetpond will not require a vegetative filter strip because
of the 90% removal efficiency. This pond will treat the 1.5" of rainfall as noted in the
Stormwater Best Management Practices Manual (6hapt6r 2, revised 9-28-07) for the coastal areas
not draining into SA waters. The outlet will release the temporary water quality over three days
using a 4-inch orifice. The release calculation is based upon a chainsaw routing method.
The wet detention pond also serves as the site's detention structure ` Area 2 is the only area that
enters into the wetpond. The city's UDO states that the "storm drainage shall be designed to
maintain the pre -developed runoff rate for the 10 year stone, and that the outlet device or
emergency spillway shall be designed to pass the 50-year storm". The pre -developed runoff rate
for area #2 (10-yr storm) was 16.40 cfs and the post rate (out of the pond) is 3.26 cfs. There is
no need for an emergency spillway since the 50-year storm passes through the outlet and has a
minimum of one foot of freeboard. The other requirement that is met per the BMP manual is the
1-yr 24-hr pre -developed runoff rate. The rates for the 1-yr 24-hr pre and post -developed runoff
rates are 6.59 cfs and 0.36 cfs respectively. When combined, areas 1 and 2 have a reduced
runoff rate for the 1, 2, 10, and 50-year storm events. This demonstrates that treating and
detaining only area 2 will have a positive effect downstream of our project.

River Road Soccer Complex
Elizabeth City, North Carolina
Storm Water Management
Report
1-23-08
Revised 03-05-08
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SOLUTIONS
2 3 2 0
W. Morehead Street
Charlotte, NC 28208
Landscape Architecture
Site Planning
Civil Engineering
w .sitesolutionspa.com
Telephone-7W521-98W
Fa imtle-704-521-8955
SS Project No. 3017
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River Road Soccer Complex
Elizabeth City, North Carolina
Storm Water Management Report
TABLE OF CONTENTS
Project Description..................................................................
• Topography
• Soils
• Model Parameters/Analysis
Conveyance Design.........................................................
• Weighted Coefft. Computations
• Time of Concentration Calculations
• "Closed" Storm Drainage System Analysis
• Culvert Analysis
• Flume Analysis
• Channel Calculations
Section 1
......... Section 2
Sedimentation and Erosion Control Measures .............................................. Section 3
• Outlet Protection Calculations
SiteHydrology........................................................................................................ Section 4
• Weighted Curve Number Computations
• Time of Concentration (TR 55): Pre (Qpre) and Post (Qpst)
• Site Hydrology Calculations
• Pond Flood Routings
BMPDesign...................................................................................
• Wet Detention Pond Design
• 2 8 5 Day Routing Calculations
• Draw Down Time Routing Calculations
IAppendix .............................
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• Site Map
• USGS Quad Map
• Pasquotank County Soil Survey
• Pasquotank County Hydrologic Soil Groups
• IDF Table
• Runoff Curve Numbers
• Runoff Coefficient Table
• Storm Cad - Pipe Diagram
• Component Drainage Area Map
• Pre -Development Drainage Area Map
• Post -Development Drainage Area Map
.............. Section 5
.................... Section 6
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River Road Soccer Complex
Elizabeth City, North Carolina
Storm Water Management Report
Revised 03-05-08
Project Description
The proposed project involves the construction five (5) new soccer fields, a
picnic shelter, and a parking facility near the existing River Road Middle
School. Site improvements will also include new "closed" storm drainage
systems, culverts, swales, and a stormwater BMP (wetpond).
Topography/Drainage
The entire site is relatively flat but generally drains from west to east with
ground elevations ranging from approximately 4.00 Ft to 9.00 Ft. The area will
continue to drain into existing drainage channels which outfall into the
Pasquotank River.
' Soils
The NCRS soil survey of Pasquotank County indicates that soils on the site are
predominately Perquimans silt loam (PeA) and Chapanoke silt loam (ChA).
These soil types are classified as Hydrologic Group C/D. Refer to the attached
copies of the Soil Conservation Service maps with site location indicated, as
well as the attached copy of the soil and water features description indicating
a the hydrologic groups that apply to the soils types indicated to be within the
project boundaries.
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Model Parameters/Analysis
Capacity analysis for proposed sedimentation and erosion control measures as
well as the storm water conveyance system design was completed using the
Rational Method. The water quality design and the sedimentation and erosion
control measures were completed using excel spreadsheets developed by Site
Solutions. The designs were based off of the most current version of NCDENR's
"Manual of Stormwater Best Management Practices" July 2007, revised in
October 2007.The onsite Erosion Control devices were designed per NCDENR
erosion control and sedimentation standards.
There are several pre -development flow areas and patterns as this site is a
relatively level site. This site generally drains from River Road to the east
property line, then to tributaries draining to the Pasquotank River (see USGS
Map attached). The post drainage discharges will be directed to the east. This
study is designed per NCDENR guidelines and therefore is designed with a Wet
Detention stormwater BMP. This wet detention pond provides 85% TSS water
quality treatment for the driveway and parking areas. The Parking lot
I

impervious areas will drain directly into the wet detention facility for water
quality treatment and storage detention. The temporary pool will be
drawndown in 2-5 days, but no earlier than 48 hours. The stormwater piping
and channels were designed for the 5-year storm event. The site hydrology and
detention requirements for this site were designed and routed using the
Bentley Pondpack program to release the pre 2-year and pre 10-year storm
events. This detention facility is designed to pass the 50-year storm event. See
the project Q Summary below. Discharge channels were improved with a 5:1
sideslope. For the delineation of the pre and post -development drainage areas,
refer to the pre -development drainage area map and post -development
drainage area map contained within these calculations.
OVERALL SITE DRAINAGE SUMMARY
5 YEAR PRE-Q DISCHARGES:
Area 1 = 41.47 cfs
Area 2 = 12.77 cfs
------------
54.24 cfs
5 YEAR POST-Q DISCHARGES:
Channel 1 = 21.27 cfs
Channel 2 = 26.03 cfs
Channel 3 = 3.23 cfs
Channel 4 = 3.31 cfs
53.84 cfs

WET DETENTION POND 1 DESIGN SUMMARY:
• 2007 NCDENR BMP design manual used
• Water Quality Volume (NCDENR Simple Method used)
• Water Quality First Flush (1.5" Runoff)
• Water Quality Treatment Provided (85% TSS)
• Req'd. WQ surface area = 12,061 SF (34,622 SF provided)
• Detention criteria used (2 year and 10 year pre-Q)
• Emergency criteria used (Pass 50 year storm)
• Req'd. Temp. pool drawdown time (2 - 5 days)
• Actual Temp. pool drawdown time = 75.76 hrs
• 1.5" Drawdown Orifice used
• Freeboard Req'd. = 12" above Temp. Pool
• Freeboard Provided = 25.2 inches above Temp. Pool
• Top of Pond Elev. = 8.60
• Permanent Pool Elev. = 5.0
• SA/DA Depth = 3.00 feet (min. req'd.)
• Permanent Pool Average Depth = 3.36 feet
• Percentage Forebay Volume = 19.90%
Wet Detention Pond 1 Summary:
- (SCS
Computer MethodHAESTAD - Method
Used*: (Area 2)P®NDPACK `. • )
Pre (cfs)
Post (cfs)
Routed (cfs)
Pond Elevation
2 yr
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_ ' 16 26� .
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6:60
10 yr
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50 yr
- ;.,` - :
41 fi " .°-
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` ..N 14�0475
POND DISCHARGE SUMMARY:
• 2 - 18" RCP @ 0.42 % used
Capacity flow = 11.61 cfs
• Discharge flow = 10.04 cfs
Also see Channel Calculations in this report

River Road Soccer Complex
Elizabeth City, North Carolina
Storm Water Management
Report
1-23-08
Revised 04-07-08
0
I�JF®
SOLUTIONS
2 3 2 0
W. Morehead Street
Charlotte, NC 28208
Landscape Architecture
Site Planning
Civil Engineering
wv7v .tesolutlonspa.com
Telephone-704-521-9880
Faoimtle-704-521-8955
SS Project No. 3017
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WET DETENTION BASIN # 1
PROJECT NAME River Road Sports Complex BY J Wehling
PROJECT NUMBER 3017 ' DATE 3/2/2008
REV. 4/2/2008
THE WET DETENTION BASIN IS DESIGNED IN ACCORDANCE WITH THE CHARLOTTE/ MECKLENBURG LAND
DEVELOPMENT REQUIREMENTS AND NCDENR'S 'STORMWATER BEST MANAGEMENT PRACTICES MANUAL",
SECTION 10, DATED JULY 2007, REVISED OCTOBER 2007.
PERMANENT WATER QUALITY POOL
CALCULATE PERCENT OF IMPERVIOUS AREA DRAINING INTO POND
PERVIOUS AREA= 1.90
IMPERVIOUS AREA=244 .,
TOTAL DRAINAGE AREA= 4.34
PERCENT IMPERVIOUS= 56.22%
ASSUME AVG. DEPTH OF PERMANENT POOL, D = 3.00 It (AVG. DEPTH SHOULD BE 3' TO 6' )
USING TABLE 10.4, DETERMINE THE REQUIRED SURFACE AREA TO DRAINAGE AREA RATIO (SA/DA)
FOR THE PERCENT IMPERVIOUS AND THE PERMANENT POOL DEPTH. (90 % TSS CHART)
TABLE 10.3
%IMP.
PERMANENT
POOL DEPTH
R
COVER
30
3.5
4.0
4.5
5.0
6.0
7.0
10
1 30
1.00
0.80
070
060
0.40
0.20
20
240
2.00
1.80
1 70
150
1.20
090
30
3.50
3.00
2.70
2.50
220
1 60
1 10
40
450
4.00
3.50
3.10
280
2.10
1.40
50
5.60
5.00
430
390
350
2.70
1.90
60
700
6.00
530
480
430
3.40
2.40
70
8A 0
7.00
600
5.50
5.00
3.90
2 90
80
9A0
800
7.00
6.40
570
460
3.40
90
10 70
900
790
7.20
650
5.20
3.90
100
12 00
1 10.00
1 880
1 8.10
730
5.80
4.30
Imp Gov
VOL ABOVE PERM POOL (cf)
Below 5000
5.00 Interpolated SA/DA
5622
X X= 562
Above 60.60
6.00
REQUIRED SURFACE AREA
OF PERM. POOL = SA/DA x DRAINAGE AREA
=024 ac
= 10,629 sf
BASIN STAGE/ STORAGE.
DWG SCALE. 1"= 1
ELEV.
I PLANIMETER READING
AREA (sf)
AVG. AREA (sf)
VOL (cf)
ACCUM. VOL (cf.)
Main Bay and
Foreba
''-1
--.3350,
3350 3350
3350
0
0
0
- 4360 _
4360
3855
3855
3855
-1
697V
6971
5161
10321
10321
"• 2
- " .`8583 -
8583
7777
7777
10098
3
.10309
10309
9446
9446
27544
'4
''12149
12149
11229
11229
38773
15681
15681
13915
13915
52688
'..6 ': ".-
_ '19510- -
19610
17646
1 17646
70334
7" -
-22410 :• =
22410
21010
21010
91344
8 -
24439 •`
24439
23425
23425
114768
1
1544. -
1544
1544
0
0
2'. _,:
a•' - -�2033 ,r --
2033
1789
1789
1789
3':-"."'.
'="2579^•;".".-"'L-.
2579
2306
2306
4095
4
-3182..
3182
2881
2881
6975
'5'- ''�
:3841
3841
3512
3512
10487
SET ELEVATION OF PERM. POOL = 5.00: • "
ACTUAL SURFACE AREA OF PERM. POOL= 15,681 sf
ACTUAL SURFACE AREA GREATER THAN REQUIRED, THEREFORE OKAY
MINIMUM PERM. POOL DEPTH = 3.00.ft (MINIMUM DEPTH ALLOWED =T)
MAXIMUM PERM POOL DEPTH = 6.00 ft. (MAXIMUM DEPTH ALLOWED =9`)
VOLUME IN PERMANENT POOL= 52.688 cf
VOLUME IN FOREBAY= 10,487 cf
AREA OF PERMANENT POOL= 15,681 sf
AVERAGE DEPTH OF POOL= 3.3611 Must be between 311 and Eft
PERCENTAGE OF TOTAL VOLUME IN FOREBAY 1990%
3017 WETDETBASIN 04-07-08 As Page 1

PROJECT NAME. River Road Sports Complex BY: J Wehling
PROJECT NUMBER3017 DATE 3/2/2008
TEMPORARY WATER QUALITY POOL
DETERMINE THE RUNOFF COEFFICIENT FOR THE FIRST 1.0 INCH OF RAINFALL:
R,= 0 05+0.009 (1) WHERE: R„= RUNOFF COEFF.
R,= 0.56 inln 1= 5622% IMPERVIOUS
DETERMINE THE VOLUME TO BE CONTROLLED THE FIRST 1.0 INCH OF RAINFALL,
VOLUME= DESIGN RAINFALL x Rv x DRAINAGE AREA WHERE DESIGN RAINFALL=1.0"
VOLUME= 0.20 ac ft Rv= 0 56 in/in
VOLUME= 8,756 cf DRAIN AREA= 4 34 ac
DETERMINE THE ELEVATION OF THE 1 0" RAINFALL' ELEV VOL ABOVE PERM POOL (cf)
ELEVATION OF THE PERM POOL= 500 5.00 0
VOLUME OF THE PERM. POOL= 52,688 cf X 8756 X= 5 50
_ 6.00, 17646
ELEVATION OF THE TEMP POOL= 5.50 (Min Req'd)
DEPTH OF TEMP. POOL (Z)= 0.50 ft
DETERMINE THE REQUIRED DRAIN SIZE TO DRAIN THE TEMP.POOL IN 2-5 DAYS (48- 120 hrs)
ASSUME 2.0 In, 0 DRAIN INV EL= 5.00 CL EL.= 5 08
DRAWDOwN ZONE
HEAD
Q
I TIME
BEGIN. EL
END EL,
ft
cis
hrs
0.17
002
9989
IUTAL IIMt IUUHAIN II,MI'YUUL= tiv.uvnrs
WHERE: HEAD =AVG. HT. ABOVE CL OF OPENING
Q= Cd x A x (2gH)o s
Cd= 0.59
A= DRAIN AREA (sl)
TIME= VOL/ Q
ANTIFLOTATION BLOCK. SQUARE
VOL OF DISPLACED WATER= RISER HEIGHT x RISER AREA
=ZxAREA
WHERE: Z= 5,50
= 197 86 cf
6.0 it long 6 0 ft wide
D= 36 00 it
WEIGHT OF DISPLACED WATER= VOL x 62 4 Ib/cf
= 12,347 lb.
WEIGHT OF CONCRETE REQUIRED= 1.1 x WE DISPLACED WATER
= 13.581 Ib
REQUIRED THICKNESS OF CONC BLOCK = WEIGHT/ (LENGTH)(WIDTH)(150-6241b/cf)
BLOCKSIZE THICKNESS
6.50 at 3.67 ft
8.00 sf 2.42 ft
9.00 $1 1.91 It
10 00 sf 1.55 ft
12 00 sf 1.08 ft
12.50 sf 0 99 ft
USE 10.00 It SQUARE BLOCK, 19 in THICK
(Use min. 12")
NOTE: Since rectangular structure, use 14LF x 9LF block
3017 WETDETBASIN 04-07-08 As
Page 2

PROJECT NAME River Road Sports Complex BY J. Wehling
PROJECT NUMBER 3017 DATE 3/2/2008
REV. 4/2/2008
WET DETENTION BASIN # 1 SUMMARY
Assumes flow over weir is less than 12" deep.
TEMP. POOL EL: 5.50
NORMAL POOL EL = 5 00
TEMP. POOL DRAIN / SHELF @ EL 4 50
EMERG. DRAIN
SHELF @ EL 5 50
3017 WETDETBASIN 04-07-08 As Page