SW7050308_HISTORICAL FILE_20070606

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

Consulting Engineers and Land Surveyors [phone] Office
[phone] Office
[phone] Fax
June 5, 2007
Mr. Bill Moore RECIEWE
Dept. of Environment and Natural Resources JUN a 6 2007
Water Quality Section
943 Washington Square Mall'�J—����
Washington, NC 27889
Subject: Stormwater Management Permit
Coastal Roofing
Project # 040475
Dear Mr -,Moore:
Enclosed is the original of the executed Designer's Certification for Stormwater
Permit No. SW7050838 for Coastal Roofing.
If you need additional information or have any questions, please do not hesitate to
call this office at [phone].
CC' file
Bill Frasca
Sincerely,
KimberlyD. Hamb
Y
Project Manager
P. 0. Box 339, Camden, NC 27921

!. m ..... __ , �. r . _ _..
.. .. ._. �(� �: �' �� ..,o _ ,f.: r1, :r .`.5 :._ ;,a:}. .1: � .f .:� ,.. .:'_ ..... 'l::�Hf .. _. -. � J.'� � ',� its.. � ..., _. .�

Human & Robev. PC
Consulting Engineers and Land Surveyors [phone] Office
[phone] Office
[phone] Fax
Ms. Amy Franklin
Dept. of Environment and Natural Resources
Water Quality Section
943 Washington Square Mall
Washington, NC 27889
Subject: Stormwater Management Permit
Coastal Roofing — revised plans
Project # 040475
Dear Amy:
October 5, 2005
RECEIVED
OCT - 7 2005
DWQ-WARD
Per our conversation today, I have enclosed a set of revised plans. The swale
behind Building A has been routed into a pipe that drains to the forebay of the pond.
Also, a note indicating that all runoff from Building B must be routed to the detention
pond has been added to the plans.
Thank you for your assistance with this project. If you have any questions or
require additional information, please do not hesitate to call me at [phone].
cc: file
Sincerely,
�f4�Kimberly D. H by
Project Manager
A D. Box 339, Camden, NC 27921

DETENTION POND ANALYSIS FILE NAME- C:\STORMWATERXPOND\SW7050838
PROJECT#: SW7 050838 REVIEWER- Afranklin
PROJECT NAME: Coastal Roofing and Siding, Lighting Protection, Inc.
DATE: 17-Oct-05
Receiving Stream: North River Class: SC
Drainage Basin: Pasquotank Index No.
Site Area 1.92 acres
Drainage Area square feet Area = 1.92 acres
IMPERVIOUS AREAS
Rational C
Building 15400.00 square feet
Streets 0.00 square feet
Parking 23280.00 square feet
Other 2005.00 square feet
square feet
square feet
06
TOTAL square feet Rational Cc= 0.10
SURFACE AREA CALCULATION
% IMPERVIOUS 48.65%
Des. Depth 6
TSS: 90
VOLUME CALCULATION
Rational ?*
Des. StormC4
inches
Rv=
0.49
Bottom
2 msl
Perm. Pool
msl
Design Pool
9.39 msl
Design SA
4020 sf
Req. Volume
' ::]I
00 cf
Prov. Volume
cf
ORIFICE CALCULATION
Avg. Head =
Flow Q2, cfs
Flow Q5, cfs
No. of Orifices
Diameter, inches
Drawdown =
0.67 ft
0.020 cfs
0.008 cfs
weir H x W
days
SA/DA Ratio 2,62%
Req. SA 2190 sf
Prov. SA € € zs'.0`1 i sf
* place a "1" in the box if Rational is used.
FOREBAY
Perm. Pool Volume=
4615
Req. Forebay Volume=
923
Provided Volume=
831.00
Percent=
SA @
Elevation=
Q2 Area =
Q5 Area =
Orifice Area
Q=
n
COMMENTS
Surface Area , Volume and Orifice are within Design Guideline:
0.72 sq. in.
0.29 sq. in.
0.79 sq. in.
0.022 cfs
x F777
in

3 Q
FINANCIAL RESPONSIBILITY/OWNERSHIP FORM 8; /ZIP `657—
SEDIMENTATION POLLUTION CONTROL ACT
No person may initiate a land -disturbing activity on one or more acres as covered by the Act
before this form and an acceptable erosion and sedimentation control plan have been completed and
approved by the Land Quality Section, NC Department of Environment, and N ' e s
type or print and, if question is not applicable, place N/A in the blank). l n
'1
Part A.
Projedt Name
2
3
Coastal Roofin
Location of land -disturbing activity:. County Cur r i t uck
City or TownshipPoplar Branch Toisnshipand Highway/Street
Approximate date land -disturbing activity will be commenced:
L.'
AUG 2 3 2005
LAND QUALITY SECTION
July 15, 2005
4. Purpose of development (residential, commercial, industrial, etc.):
d d�WU=U l'Id
5. Total acreage disturbed or uncovered (including off -site borrow and waste areas):
2.5 AUG 2 6 2005
6. Amount of fee enclosed $ 150.00 ,fir p
7. Has an erosion and sedimentation control plan been filed? Yes X No DWQ-WARO
Enclosed X
8. Person to contact should sediment control issues arise during land -disturbing activity.
Name Bill Frasca Telephone [phone]
9. Landowner(s) of Record (Use blank page to list additional owners):
Li Qh t i nQ p
Name(s)
2401 Collington Road
Current Mailing Address Current Street Address
'dill Devil Hills, NC 27948
City State Zip City State Zip
10. Recorded in Deed Book No. Page No.
Part B.
Person(s) or firm(s) who are financially responsible for this land -disturbing activity (Use a blank
page to list additional persons or firms):
William S. Frasca
Name of Person(s) or Firm(s)
2401 Collington Road
Current Mailing Address
Kill Devil Hills, NC 27948
City State Zip
City
Current Street Address
252-480-0515
Telephone Telephone
propev,4,I is LkyA r Confra& for 50t1-e
Ccos,1n3 CW -f_ 'Ls
State Zip
fo 0r1r. j owner^O�
pendfn) p-e.rm14 ckpprotxt_.1.

(a) If the Financially Responsible Party is not a resident of North Carolina give name and street
address of a North Carolina Agent.
N7nnc
Mailing Address
City State
Street Address
Zip City
Telephone Telephone
State Zip
(b) - If the Financially Responsible Party is a Partnership or other person engaging in business
under an assumed name, attach a copy of the certificate of assumed name. If the Financially
Responsible Party is a Corporation give name and street address of the Registered Agent.
Name of Registered Agent
Mailing Address
City State
Telephone
Street Address
Zip City
Telephone
State Zip
The above information is true and correct to the best of my knowledge and belief and was
provided by me under oath. (This form must be signed by the financially responsible person if
an individual or his attorney -in -fact or if not an individual by an officer, director, partner, or
registered agent with authority to execute instruments for the financially responsible person). I
agree to provide corrected information should there be any change in the information provided
herein.
GVi l l iam S . Frasca Owner
Type or name Title or Authority
Signature Date 7 ;�/_
&- n_ c- , a Notary Public of the County of -Pckscau�C, 'c
State of North Carolina, hereby certify that ats C-o,
appeared personally before me this day and being duly sworn acknowledged that the above form
was executed by him.
Witness my hand and notarial seal, this � cis " day of Jam- \ k-\ , -
Seal MARIANNE J. COOPER Notary
NOTARY PUBLIC
PASQUOTANB COUNT( NC
My commission expires (_0

H man � R be C
Consulting Engineers and Land Surveyors [phone] Office
[phone] Office
[phone] Fax
Mr. Bill Moore
Dept. of Environment and Natural Resources
Water Quality Section
943 Washington Square Mall
Washington, NC 27889
Subject: Stormwater Management Permit
Coastal Roofing
Project # 040475
Dear Mr. Moore:
August 17, 2005
tipECEME"w".
AUG 1BM5
DWQ-WARQ
Enclosed For your review and approval, please find the following items:
l . Two (2) copies of sheets 2-4 of the above referenced plans.
2. The original and one (1) copy of the Stormwater Exemption Application
and Wet Detention Basin Supplements.
3. Two (2) copies of the project description and calculations.
4. Check in the amount of $420.00 for the required fee.
If you have any questions, please do not hesitate to call this office at
[phone].
cc: file
Sincerely,
Sean C. Robey, P.E.
KimberlyD. ay
Project Manager
A O. Box 339, Camden, NC 27921

fPR0'JECT' DESCRIPTION,`
Coastal Roofing
Currituck County - North Carolina
May 19, 2005 revised July 27, 2005''
Coastal Roofing is planning to construct two office warehouse buildings on a 1.92
acre site located on Hwy 158 between Foster Forbes Road (SR It 14) and Pinewood
Acres Drive (SR 1413). The property is zoned GB (General Business).
Construction on site will include the erection of two office warehouse buildings
with related parking, septic systems, and drainage. The site will be constructed in two
phases as shown on the drawings. The buildings both contain 7,700 sf. The parking and
driveways will contribute 23,280 sf of impervious area and the concrete sidewalks and
dumpster pad contribute another 2,005 sf. The resulting impervious area is 40,685 sf or
48.65% of the overall site. These areas are designed to sheet flow to grass lined swales
with 3:1 side slopes and an underground collection system. All drainage is directed to a
wet detention basin designed for 90% TSS removal. Drainage calculations performed
utilizing the rational method indicate a pre -development run-off of 4.23 cfs and a post
development run-off of 8.47 cfs. The peak discharge from the pond will only be 3.45 cfs.
Although the on site soil type of Conetoe would support infiltration, the seasonal high
water table at ±elevation 8.0 makes a wet detention basin the most appropriate form of
stormwater treatment. Discharge from the detention pond is pipe to an existing ditch that
drains under Hwy 158 to the wetlands of North River.
The disturbed area for this site will not exceed 2.5 acres. Approximately 1.5 acres
will be disturbed during the construction of Phase 1, and less than 1 acre will be disturbed
during the construction of Phase 2.

�0� W A TE9
`0
� r
.liichaeJ F. Fxslap, Gov yv&-gQ
Whm G. Ross ire Sew
North Carolma Deftaaa= of Farrvi-w=em and Nmnal Resmu
Alas W. Klbnp k P1. Director
Df`isim of WaterQuality
September 21, 2005
Mr. William S. Frasca
Coastal Roofing and Siding, Lighting Protection, Inc
2401 Collington Road
Kill Devil Hills, NC 27948
Subject:: Stormwater Review SW7050838
Coastal Roofing
Curriuck County
Dear Mr. Frasca:
This office received a Coastal Stormwater permit application and plans for the subject
project on August 18, 2005. A preliminary review of your project indicates that before a State
Stormwater permit can be issued the following additional information is needed.
Please show on plans or discuss in narrative where the roof drains will outlet from
building B.
Please redesign pond so that a dead area is not created and that the length -to width
ratio for each entrance still meets 3:1.
> Please include proposed restrictive covenants and or deed restrictions.
The above requested information must be received in this office prior to October 21,
2005 or your application will be returned as incomplete. The return of this project will
necessitate resubmittai of all required items inciuding the application fee. If you need additional
time to submit the required information, please mail or fax your request for time extension to this
office at the Letterhead address.
You should also be aware that the Stormwater Rules require that the permit be issued
prior to any development activity. Construction without a permit is a violation of 15A NCAC
2H.1000 and North Carolina General Statute 143-215.1 and may result in civil penalties of up to
510:000 per day.
Please reference the Stormwater Project Number above on all correspondence. If you
have questions, please feel free to contact me at [phone].
cc: VA/
Washington Regional Office
Sean C. Robey, PE
Sf�ncerely,
Amy L Franklin
Environmental Engineer
Washington Regional Office
DW
NWhcamb
AiotllS czarina Dismaa of Wzr Qmbay W Repoml 0ffkc Phaac (252) %6-(A$1 FAX (252) 9WW i 5 C>mk=ff Savicc
met b2"ff_nk*MM 943 washinr &w= MA W&4imm NC 27M lam_62u,ix

Coastal Roofing
Currituck County - North Carolina
May 19 ' 2005 revised July. 27' 2005'
'Coastal Roofing is planning to construct two office warehouse buildings on a 1.92
acre site located on Hwy 158 between Foster Forbes Road (SR 1114) and Pinewood
Acres Drive (SR 1413). The property is zoned GB (General Business).
Construction on site will include the erection of two office warehouse buildings
with related parking, septic systems, and drainage. The site will be constructed in two
phases as shown on the drawings. The buildings both contain 7,700 sf. The parking and
driveways will contribute 23,280 sf of impervious area and the concrete sidewalks and
dumpster pad contribute another 2,005 sf. The resulting impervious area is 40,685 sf or
48,65% of the overall site.- These areas are designed to sheet flow to grass lined swales
with 3:1 side slopes and an underground collection system. All drainage is directed to a
wet detention basin designed for 90% TSS removal. Drainage calculations performed
utilizing the rational method indicate a pre -development run-off of 4.23 cfs and a post
development run-off of 8.47 cfs. The peak discharge from the pond will only be 3.45 cfs.
Although the on site soil type of Conetoe would support infiltration, the seasonal high
water table at ±elevation 8.0 makes a wet detention basin the most appropriate form of
stormwater treatment. Discharge from the detention pond is pipe to an existing ditch that
drains under Hwy 158 to the wetlands of North River.
The disturbed area for this site will not exceed 2.5 acres. Approximately 1.5 acres
will be disturbed during the construction of Phase 1, and less than 1 acre will be disturbed
during the construction of Phase 2.

DESC_RIPTIONr�
Coastal Roofing
Currituck County - North Carolina
May 19,.2005 revised July 27, 2005
'Coastal Roofing is planning to construct two office warehouse buildings on a 1.92
acre site located on Hwy 158 between Foster Forbes Road (SR 1114) and Pinewood
Acres Drive (SR 1413). The property is zoned GB (General Business).
Construction on site will include the erection of two office warehouse buildings
with related parking, septic systems, and drainage. The site will be constructed in two
phases as shown on the drawings. The buildings both contain 7,700 sf. The parking and
driveways will contribute 23,280 sf of impervious area and the concrete sidewalks and
dumpster pad contribute another 2,005 sf. The resulting impervious area is 40,685 sf or
48.65% of the overall site. These areas are designed to sheet flow to grass lined swales
with 3:1 side slopes and an underground collection system. All drainage is directed to a
wet detention basin designed for 90% TSS removal. Drainage calculations performed
utilizing the rational method indicate a pre -development run-off of 4.23 cfs and a post
development run-off of 8.47 cfs. The peak discharge from the pond will only be 3.45 cfs.
Although the on site soil type of Conetoe would support infiltration, the seasonal high
water table at ±elevation 8.0 makes a wet detention basin the most appropriate form of
stormwater treatment. Discharge from the detention pond is pipe to an existing ditch that
drains under Hwy 158 to the wetlands of North River.
The disturbed area for this site will not exceed 2.5 acres. Approximately 1.5 acres
will be disturbed during the construction of Phase 1, and less than 1 acre will be disturbed
during the construction of Phase 2.
CIE
PDj
EAllr-. 2005
LAND QUALITY SECT U 1
WASHINGTON REGIONAL OFFICE

PERMANENT POOL DETENTION PONDS
Hyman & Robey, PC
DESIGN OF POND
P. 0. Box 339
Camden, NC 27921
Coastal Roofing
(252)-335-1888
10 Yr, 24 Hr Storm
08/17/05
DETENTION POND
Page 1
SAIDA PERCENTAGES FOR 90% TSS REMOVAL WITHOUT VEGETATIVE FILTER
% IMPRV 3.0 FT 3.5 FT 4.0 FT
4.5 FT
5.0 FT
5.5 FT
6.0 FT
6.5 FT
7.0 FT
10 % 1.3 1.0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
20% .2.4 2.0
1.8
1.7
1.5
1.4
1.2
1.0
0.9
30 % 3.5 3.0
2.7
2.5
2.2
1.9
1.6
1.3
1.1
40 % 4.5 4.0
3.5
3.1
2.8
2.5
2.1
1.8
1.4
50 % 5.6 5.0
4.3
3.9
3.5
3.1
2.7
2.3
1.9
60 % 7.0 6.0
5.3
4.8
4.3
3,9
3.4
2.9
2.4
70 % 8.1 7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
80 % 9.4 8.0
7.0
6.4
5.7
5.2
4.6
4.0
3.4
90 % 10.7 9.0
7.9
7.2
6.5
5.9
5.2
4.6
3.9
100 % 12.0 10.0
8.8
8.1
7.3
6.6
5.8
5.1
4.3
WATERSHED AREA:
1.92
ACRES
WATERSHED % IMPERVIOUS:
48
%
PERMANENT POOL ELEVATION:
8
FT
DESIGN PERMANENT POOL DEPTH:
6
FT
SAIDA PERCENTAGE FACTOR:
2.7
%
(FROM ABOVE
TABLE - TAKEN
FRONS DESIGN OFSTOR\I WATER
POND SURFACE AREA REQ'D:
FOREBAY AREA:
AT WIDTH = 0.33 LENGTH,
WIDTH = 27.4357 LF
LENGTH = 82.3071 LF
CONTROL FACILITIES WORKSHOP MANUAL - PENC 1998)
2258 SF
677 SF
(BASED UPON MINIMUM SURFACE AREA)
Use these dimensions: WIDTH 30.72 LF
LENGTH 93.22 LF
VOLUME OF 1 ' RAINFALL
AREA OF ROOFS: 0.35 AC
AREA OF PARKING/CONCRETE: 0.58 AC
AREA OF GREEN AREAS: 0.99 AC
VOLUME OF RUNOFF 3989.37 CF
STORAGE DEPTH FOR MINIMUM AREA =
ELEVATION OF V RAINFALL = 9.39
Normal Pool Elevation
VOL (CF)=1(ROOF-1.0)+(PARKING '.95)+
1.39 FT
0
1'43,560/12

DRAWDOWN - WATER QUALITY
Q(2 DAYS) = 0.02309 CFS
Q(5 DAYS) = 0.00923 CFS
1" RUNOFF STAGE 1.39 FT
DEPTH OF DRAWDOWN DEVICE BELOW OUTLET 1.5 FT
1" RUNOFF OUTLET DEVICE: 0,85868 INCH DIA HOLE A=[QI(Cd*SQRT(2gh))]*144
Rad.=SQRT(A/PI)
Dia.=2*Rad.
DIAMETER OF HOLE TO USE: 1 INCH DIAMETER
l" STORM RUNOFF DRAWDOWN TIME 2.10667 DAYS
INFLOW HYDROGRAPH
Return Year Storm 10 Yr
Qp = Peak Discharge = S.5 cfs
Tc Time of Concentration = 22.8 min
Calculation of Tp (Time to Peak)
From SCS NEH 4 , page 15-7 Eqn, 15.4
Lag Time (L) = (1" 0.8*(S+ 1)" 0.7)1(1900*Y"0.5) for L in Hrs
where:
1 = hydraulic length of watershed (ft)
S = (1000/CN)-10
CN = approximately same CN from TR-55
Y = avg. watershed land slope in %
S = (10001CN)-10 =
2.65823
L= 0.191
hrs
From SCS NEH 4 , page 16-7 Eqn.
16.7
Tp=D12+L
where :
D = unit of excess duration rainfall (hrs)
L = Lag Time (hrs)
From SCS NEH 4 , page 16-8 Eqn. 16.12
D = 0.133 tc
where: Tc = Time of Concentration (hrs) - (See Tr-55 Printout)
THEREFORE: D = . 0.05054 hrs
Tp =
0.21627 hrs =
12.9762
min
Volume under Hydrograph
= 1.39 * Qp * Tp =
9198.82
Cubic Feet
460
2.65823
79
= 0.85
ID 'SEAL
18550
sFgtiC
�... R4 0-k
. ni
ii���rlrrftt0v

Inflow Hydrograph
SCS Dimensionless Hydrograph
Time
Discharge Time
Discharge
Volume
Ratio
Ratio hr
cfS
cf
0.00
0.00 0.00
0
0.10
0.03 0.02
0
20
0,20
0.10 0.04
1
66
0.30
0,19 0.06
2
126
0.40
0.31 0.09
3
205
0.50
0.47 0.11
4
311
0.60
0.66 0.13
6
437
0.70
0.82 0.15
7
543
0.80
0.93 0.17
8
615
0.90
0.99 0.19
8
655
1.00
1.00 0.22
9
662
1.10
0.99 0.24
8
655
1.20
0.93 0.26
8
615
1.30
0.86 0.28
7
569
1.40
0.78 0.30
7
516
1.50
0.68 0.32
6
450
1.60
0.56 0.35
5
371
1.70
0.46 0.37
4
304
1.-80
0.39 0.39
3
258
1.90
0.33 0.41
3
218
2.00
0.28 0.43
2
185
2.20
0.21 0.48
2
274
2.40
0.15 0.52
1
195
2.60
0.11 0.56
1
142
2.80
0.08 0,61
1
102
3.00
0.06 0.65
0
73
3.20
0.04 0.69
0
53
3.40
0.03 0.74
0
38
3.60
0.02 0.78
0
28
3.80
0.02 0.82
0
20
4.00
0.01 0.87
0
15
4.50
0.01 0.97
0
17
5.00
0.00 1,08
0
0
Volume under hydrograph =
8738 cf
Based upon runoff volume
= 9198.82
cf
Depth req'd for minimum area = 3.21219
ESSI".
E A L _
165S0
'1
i �, •`cyOfNES •'
C�Il at'����\\`�.

STAGE STORAGE FUNCTION OF POND
(FOR RECTANGULER DETENTION POND ONLY)
Minimum surface area taken at normal water level
BASIN AREA INCR ACCUM
VOLUME VOLUME STAGE In s
S Z
sf cf cf ft
Page 4
Pond Side Slope (M) =
In Z Z est Elevation
2864 0
0
0
Surface area at normal pool
8
3245 1527
1527
0.5
7.33
-0.69
0.50
8.5
3643 1722
3249
1
8.09
0.00
0.97
9
4060 1926
5175
1.5
8.55
0.41
1.45
9.5
4495 2139
7314
2
8.90
0.69
1.96
10
4948 2361
9674
2.5
9.18
0.92
2.50
10.5
5419 2592
12266
3
9.41
1.10
3.07
11
5907 2832
15098
3.5
9.62
1.25
3.68
11.5
6414 3080
18178
4
9.81
1,39
4.32
12
6939 3338
21516
4.5
9.98
L50
5.00
12.5
7482 3605
25122
5
10.13
1.61
5.72
13
Regression
Output:
Constant
9.34346
Ks = S/Z"b
- 3366.193
Std Err of Y Est
0,00969
R Squared
0.99962
No. of Observations
7
Degrees of Freedom
5
X Coefficient(s) 1.15215 = b
Sid Err of Coef. 0.01009
FOR VERTICAL SIDED DETENTION POND SET b=0, AND Ks = SURFACE AREA (SF)
STAGE DISCHARGE
(FOR RISER/BARRELL SPILLWAY
W EMERGENCY
WEIR)
RISER
Dr =
18
Riser Dia. (in)
Etop =
9.39
Elev. Top Riser (ft)
Cwr =
3.33
Riser weir coeff
Cdr =
0.60
Riser orifice coeff
Hln =
5
Number of Holes
H 1 d =
2
Hole Dia. (in)
EH1 -
20,00
Elev, Holes (1)
H2n -
5
Number of Holes
H2d =
2
Hole Dia. (in)
EH2 =
20.00
Elev. Holes (2)
H3n -
0
Number of Holes
H3d =
2
Hole Dia. (in)
EH3 -
20.00
Elev. Holes (3)
BARREL:
Db =
12
Barrel Dia. (in)
Einv =
8.00
Elev Invert Barrel (ft)
Cdb =
0,60
Barrel orifice coeff
11.21
Bartell Adjustment Factor
91

EMERGENCY WEIR
Page 5
Cw
=
3
Weir coeff
Ecr
=
20.00
Elev weir coeff (ft)
Lw
=
3
Weir Length (ft)
Riser
Riser
Riser
Elevation
Hole
Hole
Hole
Riser
Riser
Barrel
Principal
Emergcy
(1)
(2)
(3)
(weir)
(orifice)
Spillway
Weir
8.00
6.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.00
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.01
0.0
0.0
0.0
0.0
0.0
0.0
0,00
0.0
8.04
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.09
0.0
0.0
0.0
0.0
0.0
0.1
0.00
0.0
8.16
0.0
0.0
0.0
0.0
0.0
0.2
0.00
0.0
8.26
0.0
0.0
0.0
0.0
0.0
0.4
0.00
0.0
8,40
0.0
0.0
0.0
0.0
0.0
0.7
0.00
0.0
8.55
0.0
0.0
0.0
0.0
0.0
1.1
0.00
0.0
8,72
0.0
0.0
0.0
0,0
0.0
1.7
0.00
0.0
8.90
0.0
0.0
0.0
0.0
0.0
2.3
0.00
0.0
9.07
0.0
0.0
0.0
0.0
0.0
2.9
0.00
0.0
9.24
0.0
0.0
0.0
0.0
0.0
3.2
0.00
0.0
9.39
0.0
0.0
0.0
0.0
0.0
3.6
0.00
0.0
9.53
0.0
0.0
0.0
0.8
3.1
3.8
0.79
0.0
9.64
0.0
0.0
0.0
1.9
4.2
4.0
1.91
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.1
2.81
0.0
9.74
0.0
0.0
0.0
3.3
5.1
4.2
3.30
0.0
9.75
0.0
0.0
0.0
3.5
5.1
4.2
3.46
0.0
9.75
0,0
0.0
0.0
3.4
5.1
4.2
3.42
0.0
9,74
0.0
0.0
0.0
3.3
5.0
4.2
3.26
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.2
2.82
0.0
9.67
0.0
0.0
0.0
2.3
4.5
4.1
2.31
0.0
9.63
0.0
0.0
0.0
1.8
4,2
4.0
1.84
0.0
9.59
0.0
0.0
0.0
1.5
3.9
4.0
1.45
0.0
9.56
0.0
0.0
0.0
1.1
3.6
3.9
1.15
0.0
9.54
0.0
0.0
0.0
0.9
3.3
3.8
0.91
0.0
9.52
0.0
0.0
0.0
0,7
3.0
3.8
0.72
0.0
9.50
0.0
0.0
0.0
0.6
2.8
3.8
0.57
0.0
9.49
0.0
0.0
0.0
0.5
2.6
3.7
0.46
0.0
9.47
0.0
0.0
0.0
0.4
2.4
3.7
0.37
0.0
9.45
0.0
0.0
0.0
0.2
2.0
3.7
0.21
0.0
9.43
0.0
0.0
0.0
0.1
1.7
3.6
0.13
0.0

Page 6
ROUTING OF INFLOW HYDROGRAPH THROUGH POND AND OUTFLOW DEVICE
Total
Riser
Riser
Riser
Barrel
Emerg
Time
Inflow
Storage
Stage
Outflow
Holes
(weir)
(orifice)
Spillway
t (hr)
cfs
cf
Elevation
cfs
(1 + 2 * 3)
cfs
cfs
cfs
cfs
cfs
0.000
0
0
8.00
0.00
0.00
0.00
0.0o
0.00
0.00
0.022
0
0
8.00
0.00
0.00
0.00
0.00
0.00
0.00
0,043
1
19.8536
8.01
0.00
0.00
0.00
0.00
0.00
0.00
0.065
2
86,0321
8.04
0.00
0.00
0.00
0.00
0.02
0.00
0.087
3
211.771
8.09
0.00
0.00
0.00
0.00
0.07
0.00
0.108
4
416.925
8.16
0.00
0.00
0.00
0.00
0.18
0.00
0.130
.6
727.964
8.26
0.00
0.00
0.00
0.00
0.36
0.00
0.151
7
1164,74
8.40
0.00
0.00
0.00
0.00
0.67
0.00
0.173
8
1707.41
8.55
0.00
0.00
0.00
0.00
1.11
0.00
0.195
8
2322.87
8.72
0.00
0.00
0.00
0.00
1.65
0.00
0.216
9
2978.03
8.90
0.00
0.00
0.00
0.00
2.28
0.00
0.238
8
3639.82
9.07
0.00
0.00
0.00
0.00
2.85
0.00
0.260
8
4294.99
9.24
0.00
0.00
0.00
0.00
3.24
0.00
0.281
7
4910.45
9.39
0.00
0.00
0.00
0.00
3.56
0.00
0.303
7
5479.58
9.53
0.79
0.00
0.79
3.14
3.83
0.00
0.324
6
5934.24
9.64
1.91
0.00
1.91
4.22
4.02
0.00
0,346
5
6235.43
9.71
2.81
0.00
2.81
4.79
4.15
0.00
0.368
4
6387.41
9.74
3,30
0.00
3.30
5.06
4.21
0.00
0.389
3
6434.93
9.75
3,46
0.00
3.46
5.14
4.23
0.00
0,411
3
6423.76
9.75
3.42
0.00
3.42
5.12
4.23
0.00
0.433
2
6375.8
9.74
3.26
0.00
3.26
5,04
4.21
0.00
0.476
2
6238.58
9.71
2.82
0.00
2.82
4.80
4.15
0.00
0.519
1
6073.77
9.67
2.31
0.00
2.31
4.49
4.08
0.00
0.562
1
5908.13
9.63
1.84
0.00
1.84
4.16
4.01
0.00
0.606
1
5763.39
9.59
1.45
0.00
1.45
3.85
3.95
0.00
0.649
0
5638.88
9.56
1.15
0.00
1.15
3.56
3.90
0.00
0.692
0
5533.06
9.54
0.91
0.00
0.91
3.29
3.85
0.00
0.735
0
5445.03
9.52
0.72
Mo
0.72
3.04
3.81
0.00
0,779
0
5371.48
9.50
0.57
0100
0.57
2.82
3.78
0.00
0.822
0
5309.87
9.49
0.46
0.00
0.46
2.63
3.75
0.00
0.865
0
5257.87
9.47
0.37
0.00
0.37
2.45
3.72
0.00
0,973
0
5149.15
9.45
0.21
0.00
0.21
2.02
3.67
0.00
1.081
0
5084.37
9.43
0.13
0.00
0.13
1.71
3.64
0.00
9,75486 = maximum stage elevation
3.45845 = maximum discharge

Coastal Roofing
Currituck County
10 yr STORM
:Cft
8
7
M
6
(D
5
INFLOW (cfs)
co
4
m
OUTFLOW (cis)
3
q
W 0
2
a \M
0
0.000 0,200 0,400
0.600 0.800 1.000 1,200
Time (hrs)
✓ 18550
qN C.

POND VOLUME CALCULATIONS
FOR
S:IHyman & Robey '04W40475 - COASTAL ROOFING4ExcellPOND VOLUME CALCULATIONS (1 POND)040475.xls
POND CALCULATIONS
AREA Fz
PERMANENT POOL SURFACE AREA 2,864.27
MAIN BASIN SURFACE AREA 1.987.73
FOREBAY SURFACE AREA 876.54
AREA'A'f EDGE OF MAIN BASIN SHELF 678.86
AREA OF MAIN BASIN BOTTOM 40.56
AREA AT EDGE OF FOREBAY SHELF 65.45
AREA OF FOREBAY BOTTOM 1.70
SURFACE AREA AT 1" STORAGE 4,020.31
ELEVATIONS
PP ELEVATION
ELEVATION AT EDGE OF MAIN BASIN SHELF
ELEVATION OF MAIN BASIN BOTTOM
ELEVATION AT EDGE OF FOREBAY SHELF
ELEVATION OF FOREBAY BOTTOM
ELEVATION OF 1" STORAGE
VOLUME CALCULATIONS
MAIN BASIN VOLUME
FOREBAY VOLUME
PERMANENT POOL VOLUME
FOREBAY PERCENTAGE OF TOTAL PERMANENT POOL VOLUME
TEMP. STORAGE VOLUME (1" RUNOFF)
F
8.00
6.33
2.00
6.33
5.00
9.39
F3
3,784.15
831.22
4,615.36
18.01 %
4,784.78
TEMPORARY STORAGE OFFSET
SLOPE (EX: IF 3:1 ENTER 3) 3.00
OFFSET FROM PP 4.17
BASIN DIAGRAM CALC
MAIN POND
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDMENT SHALL BE REMOVED
FOREBAY
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDMENT SHALL BE REMOVED
08/17/2005 4:09 PM
3.50
4.50
5.75
2.25
PAGE 1 OF 1

P>JR ANENT POOL DETENTION PONDS Hyman & Robey, PC
DESIGN OF POND P. O. Box 339
Camden, NC 27921
Coastal Roofillo (252)-335-1888
10 Yr, 24 Hr Storm 08/17/05
DETENTION POND Page 1
SAIDA PERCENTAGES FOR 90% TSS REMOVAL WITHOUT VEGETATIVE FILTER
% IMPRV
3.0 FT
3.5 FT
4.0 FT
4.5 FT
5.0 FT
5.5 FT
6,0 FT
6.5 FT
7.0 FT
10 %
1.3
1.0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
20%
2A
2.0
1.8
1.7
1.5
1A
1.2
1.0
0.9
30 %
3.5
3.0
2.7
2.5
2.2
1.9
1.6
1.3
1.1
40 %
4.5
4.0
3.5
3.1
2.8
2.5
2.1
1.8
1.4
50 %
5.6
5.0
4.3
3.9
3.5
3.1
2.7.
2.3
1.9
60 %
7.0
6.0
5.3
4.8
4.3
3.9
3.4
2.9
2.4
70 %
8.1
7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
80 %
9.4
8.0
7.0
6.4
5.7
5.2
4.6
4.0
3.4
90 %
10.7
9.0
7.9
7.2
6.5
5.9
5.2
4.6
3.9
100 %
12.0
10.0
8.8
8.1
7.3
6.6
5.8
5.1
4.3
WATERSHED AREA:
WATERSHED % IMPERVIOUS:
PERMANENT POOL ELEVATION:
DESIGN PERMANENT POOL DEPTH
SAIDA PERCENTAGE FACTOR:
POND SURFACE AREA REQ'D:
FOREBAY AREA:
AT WIDTH = 0.33 LENGTH,
WIDTH = 27.4357 LF
LENGTH = 82.3071 LF
1.92 ACRES �'-'
48 %
8 FT1--
6 FTr/
?.7 % `/ (FROM ABOVE TABLE - TAKEN FROM DESIGN OF STORM WATER
CONTROL FACILITIES WORKSHOP .MANUAL - PENC 0881
2258 SF
677 SF
(BASED UPON MININIUM SURFACE AREA)
Use these dimensions: WIDTH 30.72 LF
LENGTH 93,22 LF
VOLUME OF 1 " RAINFALL
AREA OF ROOFS: 0.35 AC
AREA OF PARKING/CONCRETE: 0.58 AC
AREA OF GREEN AREAS: 0.99 AC
VOLUME OF RUNOFF 3989.37 CF
STORAGE DEPTH FOR MINIMUM AREA =
ELEVATION OF 1" RAINFALL = 9.39
Normal Pool Elevation
VOL (CF)=[(ROOF' 1.0)+(PARKING".95)
1.39 FT
0 ,' ALf
0
�+ INE6P
/,f // '441!.1 I R(164ck
8
'0.2)1'43,560/12

DRAWDOWN - WATER QUALITY
Q(2 DAYS) = 0.02309 CFS
Q(5 DAYS) = 0.00923 CFS
1 " RUNOFF STAGE 1.39 FT
DEPTH OF DRAWDOWN DEVICE BELOW OUTLET 1.5 FT
1" RUNOFF OUTLET DEVICE: 0,85868 INCH DIA HOLE A=(QI(Cd*SQRT(2gh))]*144
Rad.=SQRT(AIPI)
Dia.=2*Rad.
DIAMETER OF HOLE TO USE: 1 INCH DIAMETER
1 " STORM RUNOFF DRAWDOWN TIME 2.10667 DAYS
INFLOW HYDROGRAPH
Return Year Storm 10 Yr
Qp = Peak Discharge = 8.5 cfs
Tc = Time of Concentration = 22.8 min
Calculation of Tp (Time to Peak)
From SCS NEH 4 , page 15-7 Eqn, 15.4
Lag Time (L) = (1"0.8*(S+1)" 0.7)1(1900*Y" 0.5) for L in Hrs
where: 1 W hydraulic length of watershed (ft)
S = (1000/CN)-10
CN = approximately same CN from TR-55
Y = avg. watershed land slope in Fo
S = (1000/CN)-10 = 2.65823
L= 0.191 hrs
From SCS NEH 4 , page 16-7 Eqn. 16.7
Tp=D12+L
where : D = unit of excess duration rainfall (hrs)
L = Lag Time (hrs)
From SCS NEH 4 , page 16-8 Eqn. 16.12
D = 0.133 tc
where: Tc = Time of Concentration (hrs) - (See Tr-55 Printout)
THEREFORE: D = , 0.05054 hrs
Tp =
0.21627 hrs —
12.9762
min
Volume under Hydrograph
= 1.39 * Qp * Tp =
9198.82
Cubic Feet
60
2,65823
79
0.85
0

Inflow Hydrograph
SCS Dimensionless Hydrograph
Time
Discharge Time Discharge
Volume
Ratio
Ratio hr cfs
cf
0.00
0.00 0.00
0
0.10
0.03 0.02
0
20
0.20
0.10 0.04
1
66
0.30
0.19 0.06
2
126
0:40
0.31 0.09
3
205
0.50
0.47 0.11
4
311
0.60
0.66 0.13
6
437
0.70
0.82 0.15
7
543
0.80
0.93 0.17
8
615
0.90
0.99 0.19
8
655
1.00
1.00 0.22
9
662
1.10
0.99 0.24
8
655
1.20
0.93- 0.26
8
615
1.30
0.86 0.28
7
569
1.40
0.78 0.30
7
516
1.50
0.68 0.32
6
450
€ .60
0.56 0.35
5
371
1.70
0.46 0.37
4
304
1.180
0.39 0.39
3
258
1.90
0.33 0.41
3
218
2.00
0.28 0.43
2
185
2.20
0.21 0.48
2
274
2.40
0.15 0.52
1
195
2.60
0.11 0.56
1
142
2.80
0.08 0.61
1
102
3.00
0.06 0.65
0
73
3.20
0.04 0.69
0
53
3.40
0.03 0.74
0
38
3.60
0.02 0.78
0
28
3.80
0.02 0.82
0
20
4.00
0.01 0.87
0
15
4.50
0.01 0.97
0
17
5.00
0.00 1.08
0
0
Volume under hydrograph =
8738 cf
Based upon runoff volume
= 9198.82 cf
Depth req'd for minimum area = 3.21219
1n
Ssso
i
......
N C 10g

STAGE STORAGE FUNCTION OF POND
(FOR RECTANGULER DETENTION POND ONLY)
Minimum surface area taken at normal water level
BASIN AREA INCR ACCUM
VOLUME VOLUME STAGE In s
S Z
sf cf cf ft
Page 4
Pond Side Slope (M) =
In Z Z est Elevation
2864 0
0
0
Surface area at normal pool
8
3245 1527
1527
0.5
7.33
-0.69
0.50
8.5
3643 1722
3249
1
8.09
0.00
0,97
9
4060 1926
5175
1.5
8.55
0.41
1.45
9.5
4495 2139
7314
2
8.90
0.69
1.96
l0
4948 2361
9674
2.5
9.18
092
2.50
10.5
5419 2592
12266
3
9.41
1.10
3.07
11
5907 2832
15098
3.5
9.62
1.25
3.68
11.5
6414 3080
[8178
4
9.81
1.39
4,32
12
6939 3338
21516
4.5
9.98
1.50
5.00
12.5
7482 3605
25122
5
10.13
1.61
5.72
13
Regression
Output:
Constant
9.34346
Ks = SIZ" b
- 3366.193
Sid Err of Y Est
0.00969
R Squared
0.99962
No. of Observations
7
Degrees of Freedom
5
X Coefficient(s) 1.15215 = b
Sid Err of Coef. 0.01009
FOR VERTICAL SIDED DETENTION POND SET b=0, AND Ks = SURFACE AREA (SF)
STAGE DISCHARGE
(FOR RISER/BARBELL SPILLWAY W EMERGENCY
WEIR)
RISER
Dr =
18
Riser Dia. (in)
Etop =
9.39
Elev. Top Riser (ft)
Cwr =
3.33
Riser weir coeff
Cdr =
0.60
Riser orifice coeff
Hln =
5
Number of Holes
Hld -
2
Hole Dia. (in)
EH1 -
20.00
Eiev. Holes (1)
H2n =
5
Number of Holes
H2d =
?
Hole Dia. (in)
EH2 =
20.00
Elev. Holes (2)
H3n =
0
Number of Holes
H3d =
2
Hole Dia. (in)
EH3 -
20.00
Elev. Holes (3)
BARREL:
Db =
12
Barrel Dia. (in)
Einv =
8,00
Elev Invert Barrel (ft)
Cdb =
0.60
Barrel orifice coeff
11.21
- iaoo�
1p
ICE t iV0
Barrell Adjustment Factor
3

EMERGENCY WEIR Page 5
Cw
=
3
Weir coeff
Ecr
=
20,00
Elev weir coeff (ft)
Lw
=
3
Weir Length
(ft)
Riser
Riser
Riser
Elevation
Hole
Hole
Hole
Riser
Riser
Barrel
Principal
Emergcy
(1)
(2)
(3)
(weir)
(orifice)
Spillway
Weir
8.00
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.00
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.01
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.04
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.09
0.0
0.0
0.0
0.0
0.0
0.1
0.00
0.0
8.16
0.0
0.0
0.0
0.0
0.0
0.2
0.00
0.0
8.26
0.0
0.0
0.0
0.0
0.0
0.4
0,00
0.0
8.40
0.0
0.0
0.0
0.0
0.0
0.7
0.00
0.0
8.55
0.0
0.0
0.0
0.0
0.0
1.1
0.00
0.0
8.72
0.0
0.0
0.0
0.0
0.0
1.7
0.00
0.0
8.90
0.0
0.0
0.0
0.0
0.0
2.3
0.00
0.0
9.07
0.0
0.0
0.0
0.0
0.0
2.9
0.00
0.0
9.24
0.0
0.0
0.0
0.0
0.0
3.2
0.00
0.0
9.39
0.0
0.0
0.0
0.0
0.0
3.6
0.00
0.0
9.53
0.0
0.0
0.0
0.8
3.1
3.8
0.79
0.0
9.64
0.0
0.0
0.0
1.9
4.2
4.0
1.91
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.1
2.81
0.0
9.74
0.0
0.0
0.0
3.3
5.1
4.2
3.30
0.0
9.75
0.0
0.0
0.0
3.5
5.1
4.2
3.46
0.0
9.75
0.0
0.0
0.0
3.4
5.1
4.2
3.42
0.0
9.74
0.0
0.0
0.0
3.3
5.0
4.2
3.26
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.2
2.82
0.0
9.67
0.0
0.0
0.0
2.3
4.5
4.1
2.31
0.0
9.63
0.0
0.0
0.0
1.8
4.2
4.0
1.84
0.0
9.59
0.0
0.0
0.0
1.5
3.9
4.0
1.45
0.0
9.56
0.0
0.0
0.0
Li
3.6
3.9
1.15
0.0
9.54
0.0
0.0
0.0
0.9
3.3
3.8
0.91
0.0
9.52
0.0
0.0
0.0
0.7
3.0
3.8
0.72
0.0
9.50
0.0
0.0
0.0
0.6
2.8
3.8
0.57
0.0
9.49
0.0
0.0
0.0
0.5
2.6
3.7
0.46
0.0
9.47
0.0
0.0
0.0
0.4
2.4
3.7
0.37
0.0
9.45
0.0
0.0
0.0
0.2
2.0
3.7
0.21
0.0
9.43
0.0
0.0
0.0
0.1
1.7
3.6
0.13
0.0
�y
C. i RoO

Page 6
ROUTING OF INFLOW HYDROGRAPH THROUGH POND AND OUTFLOW DEVICE
Total
Riser
Riser
Riser
Barrel
Emerg
Time
Inflow
Storage
Stage
Outflow
Holes
(weir)
(orifice)
Spillway
t (hr)
cfs
cf
Elevation
cfs
(1+2+3)
cfs
cfs
cfs
cfs
cfs
0.000
0
0
8.00
0.00
0.00
0.00
0.00
0.00
0.00
0.022
0
0
8.00
0.00
0.00
0.00
0.00
0.00
0.00
0.043
1
19.8536
8.01
0.00
0.00
0.00
0.00
0.00
0.00
0.065
2
86.0321
8.04
0.00
0.00
0.00
0.00
0.02
0.00
0.087
3
211.771
8.09
0.00
0.00
0.00
0.00
0.07
0.00
0.108
4
416.925
8.16
0.00
0.00
0.00
0.00
0.18
0.00
0.130
6
727.964
8.26
0.00
0.00
0.00
0.00
0.36
0.00
0.151
7
1164.74
8.40
0.00
0.00
0.00
0.00
0.67
0.00
0.173
8
1707.41
8.55
0.00
0.00
0.00
0.00
1.11
0.00
0.195
8
2322,87
8.72
0.00
0.00
0.00
0.00
1.65
0.00
0.216
9
2978.03
8.90
0.00
0.00
0.00
0.00
2.28
0.00
0.238
8
3639.82
9.07
0.00
0.00
0.00
0.00
2.85
0.00
0.260
8
4294.99
9.24
0.00
0.00
0.00
0.00
3.24
0.00
0.281
7
4910.45
9.39
0.00
0.00
0.00
0.00
3.56
0.00
0.303
7
5479.58
9.53
0.79
0.00
0.79
3.14
3.83
0.00
0.324
6
5934.24
9.64
1.91
0.00
1.91
4.22
4.02
0.00
0.346
5
6235.43
9.71
2.81
0.00
2.81
4.79
4.15
0.00
0.368
4
6387.41
9.74
3.30
0.00
3.30
5.06
4.21
0.00
0.389
3
6434.93
9.75
3.46
0.00
3.46
5.14
4.23
0.00
0.411
3
6423.76
9.75
3.42
0.00
3.42
5.12
4.23
0.00
0.433
2
6375.8
9.74
3.26
0.00
3.26
5.04
4.21
0.00
0.476
2
6238.58
9.71
2.82
0.00
2.82
4.80
4.15
0.00
0.519
1
6073.77
9.67
2.31
0.00
2.31
4.49
4.08
0.00
0.562
1
5908.13
9.63
1.84
0.00
1.84
4.16
4.01
0.00
0.606
1
5763.39
9.59
1.45
0.00
1.45
3.85
3.95
0.00
0.649
0
5638.88
9.56
1.15
0.00
1.15
3.56
3.90
0.00
0.692
0
5533.06
9.54
0.91
0.00
0.91
3.29
3.85
0.00
0.735
0
5445.03
9.52
0.72
0.00
0.72
3.04
3.81
0.00
0.779
0
5371.48
9.50
0.57
0.00
0.57
2.82
3.78
0.00
0.822
0
5309.87
9.49
0.46
0.00
0.46
2.63
3.75
0.00
0.865
0
5257.87
9.47
0.37
0.00
0.37
2.45
3.72
0.00
0.973
0
5149.15
9.45
0.21
0.00
0.21
2.02
3.67
0.00
1.081
0
5084.37
9.43
0.13
0.00
0.13
1.71
3.64
Mo
9.75486 = maximum stage elevation
3,45845 = maximum discharge
I UP50
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fl
6
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21
`° 4
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Coastal Roofing
Currituck County
10 yr STORM
AMAd,
1 ®� a
M, f
"4.
°"a--®- �-
0.200 0.400 0.600 0.800 1.000 1.200
Time (hrs)
- a-- INFLOW (cfs)
�* OUTFLOW (cfs)
/ kz
K 18550 _
✓ f8550
�,• ��NGrNEtiP•� `��
C. 4i0oo

POND VOLUME CALCULATIONS
FOR
S:Hyman & Robey '041040475 - COASTAL ROOFINGIExceAPOND VOLUME CALCULATIONS (1 POND)040475.xfs
POND CALCULATIONS
AREA
PERMANENT POOL SURFACE AREA
MAIN BASIN SURFACE AREA
FOREBAY SURFACE AREA
AREA'AT EDGE OF MAIN BASIN SHELF
AREA OF MAIN BASIN BOTTOM
AREA AT EDGE OF FOREBAY SHELF
AREA OF FOREBAY BOTTOM
SURFACE AREA AT 1" STORAGE
ELEVATIONS
PP ELEVATION
ELEVATION AT EDGE OF MAIN BASIN SHELF
ELEVATION OF MAIN BASIN BOTTOM
ELEVATION AT EDGE OF FOREBAY SHELF
ELEVATION OF FOREBAY BOTTOM
ELEVATION OF 1" STORAGE
VOLUME CALCULATIONS
Fz
L,iit74.Lf
1.987,73
876.54
678,86
40.56
65.45
1.70
4,020.31
F
8.00
6,33
2.00
6.33
5.00
9.39
F3
MAIN BASIN VOLUME 3,784.15
FOREBAY VOLUME 831.22
PERMANENT POOL VOLUME 4,615.36
FOREBAY PERCENTAGE OF TOTAL PERMANENT POOL VOLUME 18,01%
TEMP. STORAGE VOLUME (1" RUNOFF) 4,784.78
TEMPORARY STORAGE OFFSET
SLOPE (EX: IF 3:1 ENTER 3) 3.00
OFFSET FROM PP 4.17
BASIN DIAGRAM CALC
MAIN POND
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDMENT SHALL BE REMOVED
FOREBAY
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDMENT SHALL BE REMOVED
08/17/2005 4:09 PM
3.50
4.50
5.75
2.25
PAGE i OF 1
�luu�■

PERMANENT POOL DETENTION PONDS
Hyman & Robey, PC
DESIGN OF POND
P. 0. Box 339
Camden, NC 27921
Coastal Roofing
(252)-335-1888
10 Yr, 24 Hr Storm
08/17/05
DETENTION POND
Page 1
SA/DA PERCENTAGES FOR 90% TSS REMOVAL WITHOUT VEGETATIVE FILTER
% IMPRV
3.0 FT
3.5 FT
4.0 FT
4.5 FT
5.0 FT
5.5 FT
6.0 FT
6.5 FT
7.0 FT
10 %
1.3
1.0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
20 %
2.4
2.0
1.8
1.7
1.5
1.4
1.2
1.0
0.9
30 %
3.5
3.0
2.7
2.5
2.2
1.9
1.6
1.3
Ll
40 %
4.5
4.0
3.5
3.1
2.8
2.5
2.1
1.8
1.4
50 %
5.6
5.0
4.3
3.9
3.5
3.1
2.7
2.3
1.9
60 %
7.0
6.0
5.3
4.8
4.3
3.9
3.4
2.9
2.4
70 %
8.1
7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
80 %
9.4
8.0
7.0
6.4
5.7
5.2
4.6
4.0
3.4
90 %
10.7
9.0
7.9
7.2
6.5
5.9
5.2
4.6
3.9
100 %
12.0
10.0
8.8
8.1
7.3
6.6
5.8
5.1
4.3
WATERSHED AREA: 1.92 ACRES
WATERSHED % IMPERVIOUS: 48 %
PERMANENT POOL ELEVATION: 8 FT
DESIGN PERMANENT POOL DEPTH: 6 FT
SA/DA PERCENTAGE FACTOR: 2.7 % (FROST ABOVE TABLE - TAKEN FROM DESIGN OF STORM WATER
CONTROL FACILITIES WORKSHOP M ANUAL - PENC 198&
POND SURFACE AREA REQ'D: 2258 SF
FOREBAY AREA: 677 SF
AT WIDTH = 0.33 LENGTH,
WIDTH = 27.4357 LF (BASED UPON MINIMUM SU
LENGTH = 82.3071 LF
Use these dimensions: WIDTH 30.72 LF
LENGTH 93.22 LF
VOLUME OF 1 " RAINFALL Normal Pool Elevation
AREA OF ROOFS: 0.35 AC
AREA OF PARKING/CONCRETE: 0.58 AC
AREA OF GREEN AREAS: 0.99 AC
VOLUME OF RUNOFF 3989.37 CF VOL (CF)={(ROOF*1.0)�(PARKING*.95)
STORAGE DEPTH FOR MINIMUM AREA = 1.39 FT
ELEVATION OF 1" RAINFALL = 9.39
AUG 33 2005
LAND QUALITY SECTION
WASHINGTON REGIONAL OFFICE
r1EAL 550
i ��''��', OINEEF:' • ��
ca0161C 1
2)1*43,560112

DRAWDOWN -WATER QUALITY
Q(2 DAYS) = 0.02309 CFS
Q(5 DAYS) = 0.00923 CFS
I" RUNOFF STAGE 1.39 FT
DEPTH OF DRAWDOWN DEVICE BELOW OUTLET 1.5 FT
1" RUNOFF OUTLET DEVICE: 0.85868 INCH DIA HOLE A=(Q/(Cd*SQRT(2gh))]*144
Rad.=SQRT(A/Pi)
Dia.=2*Rad.
DIAMETER OF HOLE TO USE: I INCH DIAMETER
I" STORM RUNOFF DRAWDOWN TIME 2.10667 DAYS
INFLOW HYDROGRAPH
Return Year Storm 10 Yr
Qp = Peak Discharge = 8.5 cfs
Tc = Time of Concentration = 22.8 min
Calculation of Tp (Time to Peak)
From SCS NEH 4 , page 15-7 Eqn. 15.4
Lag Time (L) = (1"0.8*(S+1)"0.7)/(1900*Y" 0.5) for L in Hrs
where: 1 = hydraulic length of watershed (ft)
S = (1000/CN)-10
CN = approximately same CN from TR-55
Y = avg. watershed land slope in
S = (1000/CN)-10 = 2.65823
L = 0.191 hrs
From SCS NEH 4 , page 16-7 Eqn. 16.7
Tp=D/2+L
where : D = unit of excess duration rainfall (hrs)
L = Lag Time (hrs)
From SCS NEH 4 , page 16-8 Eqn. 16.12
D = 0.133 tc
where: Tc = Time of Concentration (hrs) - (See Tr-55 Printout)
THEREFORE: D = 0.05054 hrs
Tp =
0.21627 hrs =
12.9762
min
Volume under Hydrograph
= 1.39 * Qp * Tp =
9198.82
Cubic Feet
460
2.65823
79
0.85

Inflow Hydrograph
SCS Dimensionless Hydrograph
Time
Discharge Time
Discharge
Volume
Ratio
Ratio
hr cfs
cf
0.00
0.00
0.00
0
0.10
0.03
0.02
0
20
0..20
0.10
0.04
1
66
0.30
0.19
0.06
2
126
0:40
0.31
0.09
3
205
0.50
0.47
0.11
4
311
0.60
0.66
0.13
6
437
0.70
0.82
0.15
7
543
0.80
0.93
0.17
8
615
0.90
0.99
0.19
8
655
1.00
1.00
0.22
9
662
1.10
0.99
0.24
8
655
1.20
0.93
0.26
8
615
1.30
0.86
0.28
7
569
1.40
0.78
0.30
7
516
1.50
0.68
0.32
6
450
1.60
0.56
0.35
5
371
1.70
0.46
0.37
4
304
1:80
0.39
0.39
3
258
1.90
0.33
0.41
3
218
2.00
0.28
0.43
2
185
2.20
0.21
0.48
2
274
2.40
0.15
0.52
1
195
2.60
0.11
0.56
1
142
2.80
0.08
0,61
l
102
3.00
0.06
0.65
0
73
3.20
0.04
0.69
0
53
3.40
0,03
0.74
0
38
3.60
0.02
0.78
0
28
3.80
0.02
0.82
0
20
4.06
0.01
0.87
0
15
4.50
0.01
0.97
0
17
5.00
0.00
1.08
0
0
Volume under
hydrograph =
8738 cf
Based upon runoff volume = 9198.82 cf Depth req'd for minimum area = 3.21219
' J�EAL
/ 18550
i
rrm1

STAGE STORAGE FUNCTION OF POND
(FOR RECTANGULER DETENTION POND ONLY)
Minimum surface area taken at normal water level
BASIN AREA INCR ACCUM
VOLUME VOLUME STAGE In s
S z
sf cf cf ft
Pond Side Slope (M) =
In Z Z est Elevation
2864 0
0
0
Surface area at normal pool
8
3245 1527
1527
0.5
7.33
-0.69
0.50
8.5
3643 1722
3249
1
8.09
0.00
0.97
9
4060 1926
5175
1.5
8.55
0.41
1.45
9.5
4495 2139
7314
2
8.90
0.69
1.96
10
4948 2361
9674
2.5
9.18
0.92
2.50
10.5
5419 2592
12266
3
9.41
1.10
3.07
11
5907 2832
15098
3.5
9.62
1.25
3.68
11.5
6414 3080
18178
4
9.81
1.39
4.32
12
6939 3338
21516
4.5
9.98
1.50
5.00
12.5
7482 3605
25122
5
10.13
1.61
5.72
13
Regression
Output:
Constant
9,34346
Ks = S/Z"b
- 3366.193
Std Err of Y Est
0.00969
R Squared
099962
No. of Observations
7
Degrees of Freedom
5
X Coefficient(s) 1.15215 = b
Std Err of Coef. 0,01009
FOR VERTICAL SIDED DETENTION POND SET b=0, AND Ks = SURFACE AREA (SF)
STAGE DISCHARGE
(FOR RISER/BARRELL SPILLWAY
W EMERGENCY WEIR)
RISER
Dr -
18
Riser Dia. (in)
Etop =
9.39
Elev. Top Riser (ft)
Cwr =
3.33
Riser weir coeff
Cdr =
0.60
Riser orifice coeff
H 1 n =
5
Number of Holes
H 1 d =
2
Hole Dia. (in)
EHI =
20.00
Elev. Holes (1)
H2n =
5
Number of Holes
H2d -
2
Hole Dia. (in)
EH2 =
20.00
Elev. Holes (2)
H3n =
0
Number of Holes
H3d =
2
Hole Dia. (in)
EH3 =
20.00
Elev. Holes (3)
BARREL:
Db -
12
Barrel Dia. (in)
Einv =
8.00
Elev Invert Barrel (ft)
Cdb =
0.60
Barrel orifice coeff
11.21
Page 4
-6EAL
SFaN
Barrell Adjustment Factor
3

EMERGENCY WEIR Page 5
Cw
-
3
Weir coeff
Ecr
=
20.00
Elev weir coeff (ft)
Lw
-
3
Weir Length
(ft)
Riser
Riser
Riser
Elevation
Hole
Hole
Hole
Riser
Riser
Barrel
Principal
Emergcy
(1)
(2)
(3)
(weir)
(orifice)
spillway
Weir
8.00
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.00
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.01
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.04
0.0
0.0
0.0
0.0
0.0
0.0
0.00
0.0
8.09
0.0
0.0
0.0
0.0
0.0
0.1
0.00
0.0
8.16
0.0
0.0
0.0
0,0
0.0
0.2
0.00
0.0
8.26
0.0
0.0
0.0
0.0
0.0
0.4
0.00
0.0
8.40
0.0
0.0
0.0
0.0
0.0
0.7
0.00
0.0
8.55
0.0
0.0
0.0
0.0
0.0
1.1
0.00
0.0
8.72
0.0
0.0
0.0
0.0
0.0
1.7
0.00
0.0
8.90
0.0
0.0
0.0
0.0
0.0
2.3
0.00
0.0
9.07
0.0
0.0
0.0
0.0
0.0
2.9
0.00
0.0
9.24
0.0
0.0
0.0
0.0
0.0
3.2
0.00
0.0
9.39
0.0
0.0
0.0
0.0
0.0
3.6
0.00
0.0
9.53
0.0
0.0
0.0
0.8
3.1
3.8
0.79
0.0
9.64
0.0
0.0
0.0
1.9
4.2
4.0
1.91
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.1
2.81
0.0
9.74
0.0
0.0
0.0
3.3
5.1
4.2
3.30
0.0
9.75
0.0
0.0
0.0
3.5
5.1
4.2
3.46
0.0
9.75
0.0
0.0
0.0
3.4
5.1
4.2
3.42
0.0
9.74
0.0
0.0
0.0
3.3
5.0
4.2
3.26
0.0
9.71
0.0
0.0
0.0
2.8
4.8
4.2
2.82
0.0
9.67
0.0
0.0
0.0
2.3
4.5
4.1
2.31
0.0
9.63
0.0
0.0
0.0
1.8
4.2
4.0
1.84
0.0
9.59
0.0
0.0
0.0
1.5
3.9
4.0
1.45
0.0
9.56
0.0
0.0
0.0
1.1
3.6
3.9
1.15
0.0
9.54
0.0
0.0
0.0
0.9
3.3
3.8
0.91
0.0
9.52
0.0
0.0
0.0
0.7
3.0
3.8
0.72
0.0
9.50
0.0
0.0
0.0
0.6
2.8
3.8
0.57
0.0
9.49
0.0
0.0
0.0
0.5
2.6
3.7
0.46
0.0
9.47
0.0
0.0
0.0
0.4
2.4
3.7
0.37
0.0
9.45
0.0
0.0
0.0
0.2
2.0
3.7
0.21
0.0
9.43
0.0
0.0
0.0
0.1
1.7
3.6
0.13
0.0
M SEAL
� 18550
�i`PF,gy'C. R9j%
/�����11lI i 111t11111�

Page 6
ROUTING OF INFLOW HYDROGRAPH THROUGH POND AND OUTFLOW DEVICE
Total
Riser
Riser
Riser
Barrel
Emerg
Time
Inflow
Storage
Stage
Outflow
Holes
(weir)
(orifice)
Spillway
t (hr)
cfs
cf
Elevation
cfs
(1+2+3)
cfs
cfs
cfs
cfs
cfs
0.000
0
0
8.00
0.00
0.00
0.00
0.00
0.00
0.00
0.022
0
0
8.00
0.00
0.00
0.00
0.00
0.00
0.00
0.043
1
19.8536
8.01
0.00
0.00
0.00
0.00
0.00
0.00
0.065
2
86.0321
8.04
0.00
0.00
0.00
0.00
0.02
0.00
0.087
3
211.771
8.09
0.00
0.00
0.00
0.00
0.07
0.00
0.108
4
416.925
8.16
0.00
0.00
0.00
0.00
0.18
0.00
0.130
6
727.964
8.26
0.00
0.00
0.00
0.00
0.36
0.00
0.151
7
1164.74
8.40
0.00
0.00
0.00
0.00
0.67
0.00
0.173
8
1707.41
8.55
0.00
0.00
0.00
0.00
1.11
0.00
0.195
8
2322.87
8.72
0.00
0.00
0.00
0.00
1.65
0.00
0.216
9
2978.03
8.90
0.00
0.00
0.00
0.00
2.28
0.00
0.238
8
3639.82
9.07
0.00
0.00
0.00
0.00
2.85
0.00
0.260
8
4294.99
9.24
0.00
0.00
0.00
0.00
3.24
0.00
0.281
7
4910.45
9.39
0.00
0.00
0.00
0.00
3.56
0.00
0.303
7
5479.58
9.53
0.79
0.00
0.79
3.14
3.83
0.00
0.324
6
5934.24
9.64
1.91
0.00
1.91
4.22
4.02
0.00
0.346
5
6235.43
9.71
2.81
0.00
2.81
4.79
4.15
0.00
0.368
4
6387.41
9.74
3.30
0.00
3.30
5.06
4.21
0.00
0.389
3
6434.93
9.75
3.46
0.00
3.46
5.14
4.23
0.00
0.411
3
6423.76
9.75
3.42
0.00
3.42
5.12
4.23
0.00
0.433
2
6375.8
9.74
3.26
0.00
3.26
5.04
4.21
0.00
0.476
2
6238.58
9.71
2.82
0.00
2.82
4.80
4.15
0.00
0.519
l
6073.77
9.67
2.31
0.00
2.31
4.49
4.08
0.00
0.562
1
5908.13
9.63
1.84
0.00
1.84
4.16
4.01
0.00
0.606
1
5763.39
9.59
1.45
0.00
1.45
3.85
3.95
0.00
0.649
0
5638.88
9.56
1.15
0.00
1.15
3.56
3.90
0.00
0.692
0
5533.06
9.54
0.91
0.00
0.91
3.29
3.85
0.00
0.735
0
5445.03
9.52
0.72
0.00
0.72
3.04
3.81
0.00
0.779
0
5371.48
9.50
0.57
0.00
0.57
2.82
3.78
0.00
0.822
0
5309.87
9.49
0.46
0.00
0.46
2.63
3.75
0.00
0.865
0
5257.87
9.47
0.37
0.00
0.37
2.45
3.72
0.00
0.973
0
5149.15
9.45
0.21
0.00
0.21
2.02
3.67
0.00
1.081
0
5084.37
9.43
0.13
0.00
0.13
1.71
3.64
0.00
9.75486 = maximum stage elevation
3.45845 = maximum discharge

Coastal Roofing
Currituck County
10 yr STORM
9
Nift
7
4 6
a) 5 INFLOW (cfs)
N-
4 OUTFLOW (cfs)
3
2
4.
0.000 0.200 0.400 0.600 0.800 1,000 1.200
Time (hrs)
WMEAL
..I N EOk"
........ NN
c. fo)o

POND VOLUME CALCULATIONS
FOR
S:1Hyman & Robey '041040475 - COASTAL ROOFING1ExceAPOND VOLUME CALCULATIONS (1 POND)040475.x1s
POND CALCULATIONS
AREA F2
PERMANENT POOL SURFACE AREA 2,864.27
MAIN BASIN SURFACE AREA
FOREBAY SURFACE AREA
AREA'A"f EDGE OF MAIN BASIN SHELF
AREA OF MAIN BASIN BOTTOM
AREA AT EDGE OF FOREBAY SHELF
AREA OF FOREBAY BOTTOM
SURFACE AREA AT 1" STORAGE
ELEVATIONS
PP ELEVATION
ELEVATION AT EDGE OF MAIN BASIN SHELF
ELEVATION OF MAIN BASIN BOTTOM
ELEVATION AT EDGE OF FOREBAY SHELF
ELEVATION OF FOREBAY BOTTOM
ELEVATION OF 1" STORAGE
VOLUME CALCULATIONS
MAIN BASIN VOLUME
FOREBAY VOLUME
PERMANENT POOL VOLUME
FOREBAY PERCENTAGE OF TOTAL PERMANENT POOL VOLUME
TEMP. STORAGE VOLUME (1" RUNOFF)
1.987.73
876.54
678.86
40.56
65.45
1.70
4.020.31
F
8.00
6.33
2.00
6.33
5.00
9.39
F3
3,784.15
831.22
4,615.36
18.01 %
4,784.78
TEMPORARY STORAGE OFFSET
SLOPE (EX: IF 3:1 ENTER 3) 3.00
OFFSET FROM PP 4.17
BASIN DIAGRAM CALC
MAIN POND
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDIMENT SHALL BE REMOVED
FOREBAY
SEDIMENT REMOVAL ELEVATION
PP DEPTH READS ... SEDMENT SHALL BE REMOVED
08/17/2005 4:09 PM
3.50
4.50
5.75
2.25
PAGE 1 OF 1
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