SW8021023_COMPLIANCE_20030324

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE '
OMPLIANCE EVALUATION INSPECTION
DOC DATE
3�
YYYYMMDD

DE-TENTION POND ANALYSIS FILENAME: G:IDATAIWPDATAIWQSIPOND1021023.WK1
PROJECT #: SW8 021023 REVIEWER: L. Lewis
PROJECT NAME: Jacksonville A -Storage Inn
DATE:
24-Mar-03
Receiving Stream:
Sandy Run Branch
Class:
SC NSW
Drainage Basin:
White Oak
Index No.
WOK02 19-10-1
Site Area
3.64 acres
Drainage Area
153.767
square feet
Area =
3.53 acres
IMPERVIOUS AREAS
Buildings 48010.00 square feet
Asphalt 48744.00 square feet
square feet
square feet
square feet
square feet
TOTAL :96754Q0 square feet
SURFACE AREA CALCULATION
% IMPERVIOUS 62.92%
Des. Depth 4
TSS: 90
Rational C
Rational Cc= 0.07
SA/DA Ratio 5,50%
Req. SA 8464 sf
Prov. SA 8737 sf
VOLUME CALCULATION * place a "1" in the box if Rational is used
Rational ?*
Des. Storm>:::.»1';:00:>
- ......
inches
Rv=
0.62
Bottom
2 msl
Perm, Pool
`:._00' msl
Design Pool
7.2 msl
Design SA
10849 sf
Req. Volume
7897<
cf
Prov. Volume
11.7:52<
cf
ORIFICE CALCULATION
3o: := 1
Perm. Pool Volume= 21501
Req. Forebay Volume= 4300.2
Provided Volume= 4353.00
Percent= 2t3:2°0
SA @ _
Elevation=
Avg. Head =
0.57
ft
Q2 Area =
1.81
sq. in.
Flow Q2, cfs
0.046
cfs
Q5 Area =
0.72
sq. in.
Flow Q5, cfs
0.018
cfs
Orifice Area
1.77
sq. in.
No. of Orifices
0.045
cfs
Diameter, inches
::... 5=
weirHxW
;: :.
i n
x
in
Drawdown =
2
days
COMMENTS
Surface Area , Volume and Orifice are within Design Guidelines

INFILTRATION TRENCH ANALYSIS
Filename: G:IDATAIWPDATAIWQSIINTRENCH1021023
Project # 021023
Project Name Jacksonville A -Storage Inn
Recvng Stream Sandy Run Branch
Drainage Basin White Oak
Site Area 3.64 acres
Impervious Area Calculation
Buildings
Parking/Asphalt
Concrete
Total
Volume/Storage Calculation
7296
If Rational Method is used, place a 1 in this box
Required
Provided
Design Storm
RV
Valume<ti. Store
Pipe Diameter
Length Of a Single run of Pipe
Number of Pipe Runs in Trench
Storage In Piping
Total Storage in Piping
Cross -Sectional Area Of Pipe Runs
Length Of Trench
Width Of Trench
Height Of Trench
Cross -Sectional Area Of Trench
Voids Volume, 40%
Trench Volume per linear foot
Minimum Trench length required
Total Volume Provided
Elevation Of Bottom Of Trench
Elevation Of SHWT
Overflow Elevation
Exfiltration Rate / Drawdown
Reported Hydraulic Conductivity
Bottom Surface Area
Drewdown �: irne
Date 12-Mar-03
Reviewer L. Lewis
Classification SC NSW
Index # WOK02 19-10-1
Drainage Area 7296 SF
0.17 Acres
Rational Cc (list C after each BUA)
1
r
% Impervious: 100.0%
Cc: 1.00
2 in
0.95
1216 CF
Pipe Size 1 Pipe Size 2
Comments:
Required volume, storage, and drawdown guidelines are met.
15.6 Mean Sea Level
13.6 Mean Sea Level
17.1 Mean Sea Level
0.083 Cubic Feet Per Hour Per Sq Ft
1575 Square Feet
,9.5Phours

� r
0 C T 2 2 2002
TECHNICAL SPECIFICATIONS
FOR
STORMWATER DETENTION POND
TO SERVE
1
JACKSONVILLE A -STORAGE INN
JACKSONVILLE, NORTH CAROLINA
1
OWNER:
t JACKSONVILLE A -STORAGE INN
Jacksonville, North Carolina
1
' OCTOBER 2002
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PARKER & ASSOCIATES, INC:
Engineering - Surveying - Land Planning
P.O. Box 976
Jacksonville, North Carolina 28541
' . •:, ,910-455-24.14

Copyright ® 2002 by parker & ABSOCIates, Ina.
A31 rights reserved. No part of this docunlOnt MOY without prlot
be reproduced in any form or by any mean°
written permiesi°u- in6 endtW p A by
those e*ma* au
s cr�i
t
1
1

STORMWATER NARRATIVE
JACKSONVILLE A STORAGE INN
.The'Jacksonviile A Starage'lnn is'an existing Mini Storage Facility located on
Hwy 17 in Jacksonville. The Owner is proposing to construct additional mini storage.
buildings at the site.
The stormwater runoff from the project addition will be treated in two locations.
The rear portion of the project will be collected and transported to a Wet Detention
Pond. Stormwater runoff from the existing storage area will be routed around the basin.
Stormwater from the small parking lot addition will be treated in an underground
infiltration system. Runoff will sheet flow from the parking lot over a grassed swale to a
yard inlet. Overflow will be to the existing grassed swale along Hwy 17.
d
cl .GRM.A.Storage.Nar

JACKSONVILLE A STORAGE INN
ONSLOW COUNTY, NORTH CAROLINA
STORMWATER DETENTION POND
ENGINEERING CALCULATIONS
October 2002
1. AREA
Total Area Draining to Pond from Buildings, Drives, and
Parking Lot (including pond area).......... 3.53 Acres
Impervious Area:
Building, Drives & Parking 96,754 S.F. = 2.22 Acres
Percentlmpervious = Impervious _ 2.22 = 63%
total 3.53
2. PERMANENT POND SURFACE AREA
From Chart 4 - Appendix E from D.E.M. Report 87-05, for 63%
impervious (interpolate), 4.0 Ft. basin depth without
Vegetative Filter (90% TSS Removal) Yields SA/DA = 5.51%
3.53 acres x 5.51% = 0.1945 acres or 8472 S.F. surface area
required
Top of permanent pond elevation is 6.0
Area at 6.0 elevation = 8737 S.F. provided
8737 S.F. provided _>8472 S.F.
required
3. TEMPORARY DETENTION STORAGE VOLUME
Retain 1° of runoff from area draining to pond
Total Area = 3.53 Acres
Total Runoff = (( 2.22 x 1.0 ) + ( 1.31 x 0.4 )) x 1.0 in.
2.74 Ac. - In.

ENG-2
Find Temporary Storage volume
2.74 Ac.-In x 3,630 C.F. = 9,946 C.F. recuired
Ac.-In.�
4-.'-. TEMPORARY DETENTION STORAGE VOLUME
Use'1.2'Ft. Temporary Pool
Area at 6.0 elevation (permanent pond) = 8,737 S.F.
Area at 7.2 elevation (temporary pond) = 10,849 S.F.
Average Area = 9,793 S.F.
Storage Vol. = 9,793 S.F. x 1.2 Heightf= 11,752 C.F. provided
11,752 C.F. provided > 9,946 C.F. required O.K.
S. RELIEVE TEMPORARY STORAGE VOLUME IN 2 TO 5 DAYS
(Use Volume Required)
Q = CD Argh (orifice equation)
Q = 9,946 C.F. _ 2 days = 0.0576 CFS
Q = 9,946 C.F. _ 5 days = 0.0230 CFS
Cd = 0.60
g = 32.2 ft/sec
h = 0.6 ft average height
For 2 Day release
Solve for A = Q = 0.0576 = 0.0154 S.F.
CD 2gh (0. 6) V2 (32.2) (0. 6)
Solve for Orifice Diameter, D
A = 0.0154 S.F. = n R2
R = 0.0701 FT. = 0.84 inch
D = 1.68 inch

ENG-3
For 5 Day Release
Soave For A = Q = 0.0230 = 0.0062 S.F.
CD 2gh (0.6) 2 (32.2) (0. 6)
Solve for Orifice Diameter,'D
A = 0.0062 S.F. = n R2
R = 0.0443 FT. = O.S3 inch
D = 1.06 inch
Use 1.5 inch diameter orifice
6. SIZE INLET RISER PIPE AND OUTLET PIPES TO HANDLE 10 YR. 1 HR.
STORM
A. Storm Flow
Q = CiA
A = 3.53 acres
C = 0.7
I = 2.88 in/hr - ten year, one hour
Q = 0.7 (2.88) (3.53) = 7.1 cfs
B. Inlet Riser Pipe
Water height before topping pond =
9.0 - 7.2 = 1.8
Q = Cd A 2gh (orifice equation)
Cd = 0.6 (typical value)
H = 1.8
Q = 7.1
29 = 64.4
Solve For A = Q = 7.1 = 1.099 S.F.
CD 2gh (0.6)V2 (32.2) (1.8)

ENG-4
Solve for Riser Pipe Diameter, D
A = 1.099 S.F. = n R2
R = 0.59 ft. = 7.1 inches
D = 14.2 inches
Use .1-1811 Pipe
C. Outlet Pipe
1. Check Inlet Control
Use reference Chart 5, Bureau of Public Roads Jan. 1963
Setting invert of outlet pipe at 6.0 with top of pond at 9.0
Hw = 9.0 - 6.0 = 3.0
Assume 18" Diameter
Hw = 3.0 = 2.0
D 1.5
Entrance Type 1
From chart, Q = 13 CFS > 7.1 CFS O.K.
Use 1-18" pipe
7. 100 -YEAR FLOOD
Q = CIA
Composite C = 0.6
I100 = 4.15 in/hr for 1 hour duration flood
A = 3.53 Acres
Q = 0.7 (4.15) (3.53) = 10.3 CFS
Design to handle 100-yr flood through riser and outlet
pipes prior to topping pond
Top of pond = 9.0
A. Riser Weir
Assume 18" pipe
Q = Cd A 2 gh
H = 9.0 - 6.0 = 3.0

ENG-5
A = n R1=,n(1.512)2= 1.77ft.'
Cd = 0.6
Q = 0.6(1.77) 2(32.2)(3.0)
Q = 14.8 CFS > 10.3 CFS OK
B. Outlet Pier
Use Chart 5, Bureau of Public Roads, Jan. 1963
Hw=9.0-6.0=3.0
Diameter = 18"
Hw=3_0=2.0
D 1.5
From chart, Q = 13 CFS > 10.3 CFS OK
:. Riser and outlet pipes will handle 100 yr. storm. No spillway required.
8.
Forebay
Volume
Forebay Volume shall contain approximately
20% of the total permanent pond
volume. (Permanent Pool Volume)
DETERMINE PERMANENT POOL VOLUME
Area in main pond at bottom elevation 2.0
- 1898 ft2
Area in main pond at permanent pool
elevation 6.0
= 6676 ft2
TOTAL
= 8574 ft2
4
Average = 8574 ft212
= 4287 ft2
N
Volume = 4287 ft2 X 4 ft
= 17,148 ft3
3�
a�
Area in Forebay at bottom elevation 3.0
= 999 ft2
3
.
Area in Forebay at permanent pool
elevation 6.0
- 1902 ft2
TOTAL
= 2901 ft2
Average - 2901 ft212
= 1451 ft2
Volume = 1451 ft2 X 3 ft.
= 4353 ft.3
TOTAL PERMANENT POOL VOLUME = 17,148 ft.3 + 4353 ft.3
= 21,501 ft.3
Forbay Volume 1 Permanent Pool Volume - 4353 ft.3 l21,501 ft.3
20.3 % OK
c1.GRM.A.Storage.Rev.Pg.S.Pond. CaI

JACKSONVILLE A -STORAGE INN
STORMWATER INFILTRATION TRENCH RECEIVED
ENGINEERING CALCULATIONS
JAN 15 2003
DWQ
PROD # a2ro23
Impervious Area = 7,326 S.F.
*Retain 2.0 inch rainfall event over impervious area = 7,326 S.F. x 2.0 in. x 1 ft.
12 in.
= 1221 C.F. (Required Volume)
Stormwater Infiltration Assembly
Area of 1 - 12 in. Diameter pipe = 0.785 S.F.
Try 4 -12 in. Pipes with 18 in. Stone each side and 12 in. separating pipes, yields trench area
of 1.5ft. x 10.5ft=15.75S.F.
Trench area - pipe area
12.61 x 0.4(40% voids)
5.04 S.F. + 4(.785)
1221 C.F./ 8.18 S.F.
150 L.F. Trench Provided
= 15.75 - 4(0.785)
= 12.61 S.F.
= 5.04 S.F.
= 8.18 S.F.
= 149 L.F. Trench Required
Drawdown Time: 18 in. Trench Depth using worst case infiltration rate = 1.0 M./hr.
Drawdown Time = I hr x 18 in. = 18 hours
lrn
*Use 2.0 Inch event in order not to provide bypass
c I .GRM -A.Storage.Inn.SIT.CaI
ARW
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