SW6200101_Wet Pond #1 Calculations_Revised March2020_3/9/2020

�I
Mason&Hanger
noay&zm -.a rim
Civil Affairs TEMF
Fort Bragg, Cumberland County, North Carolina
APPENDIX
WET POND BASIN CALCULATIONS
Mason & Hanger Page - a.9 -

SUPPLEMENT-EZ FORM COVER PAGE
Please indicate the types, quantities and locations of SCMs that will be used on this project:
Quantity
Location(s)
Infiltration System
Bioretention Cell
1
Bioretention Pond
Wet Pond
2
Wet Pond #1 & Wet Pond #2
Stormwater Wetland
Permeable Pavement
Sand Filter
Rainwater Harvesting
Green Roof
Level Spreader -Filter Strip
Disconnected Impervious Surface
Treatment Swale
Dry Pond
Designer information for this project:
Name and Title:
Organization:
Street address:
Mike Mayer, Civil Engineer
Mason & Hanger
300 W Vine St Suite 1300
City, State, Zip:
Lexington, KY 40507
Phone number(s):
859-280-3557
Email:
[e-mail]
Designer
Seal
Signature of Designer
Date
Applicant:
Project Name:
SOF Civil Affairs
Address
Fort Bragg
City i Town
Fayetteville
Environmental
Q-11ty
Company:
Fort Bragg DPW
Contact:
Lee Ward
Mailing Address:
Bldg 3-1333 Butner Rd
City, State, Zip:
Fort Bragg, NC 28310
Phone number(s):
[phone]
Email:
[e-mail]
Certification Statement:
I certify, under penalty of law: that this Supplement-EZ form and all supporting
information were prepared under my direction or supervision;
- that the information provided in the form is, to the best of my knowledge
and belief, true, accurate, and complete; and
- that the engineering plans, specifications, operation and maintenance
agreements and other supporting information are consistent with
the information provided here.
I am aware that there are significant penalties for submitting false
information including the possibility of fines and imprisonment for knowing
violations as well as a report being made to my professional board.
Cover Page 1 8:00 AM 10/4/2019

Ft Bragg Civil Affairs
Stormwater Pond Volume Comparison
Revised March-2020
Bioretention Pond #1 I NCDEQ Requirements (cf) EISA Option #1 Requirements (cf) Provided in Design (cf) I
Bioretentin Storage Requirements 15,900 1 16,378 1 16,701
Wet Pond #1
NCDEQ Requirements (cf)
EISA Option #2 Requirements (cf)
Pre vs Post Development (10-yr)
Provided in Design (cf)
Volume Main Pool VMv
28,756
37,893
38,959
Volume of Forebay VFB
4,313
5,684
6,330
Design Volume Dv
11,805
21,429
30,501
Wet Pond #2
NCDEQ Requirements (cf)
EISA Option #2 Requirements (cf)
Pre vs Post Development (10-yr)
Provided in Design (cf)
Volume Main Pool VMv
89,090
111,165
116,538
Volume of Forebay VFB
13,364
16,675
18,930
Design Volume Dv
36,572
65,830
74,633

NI
Mason&Hanger
noayazm —.a rim
Civil Affairs TEMF
Fort Bragg, Cumberland County, North Carolina
STORM WATER WET POND #1
(BASIN #2)
CALCULATIONS
Mason & Hanger. Page - a.12 -

WinTR-55 Current Data Description
Identification Data
User: SCurry Date: 10/3/2019
Project: Ft Bragg CA TEMF_Wet Pond Units: English
SubTitle: Pre -Development Wet Pond #1, Qp Areal Units: Acres
State: North Carolina
County: Cumberland NOAA-B
Filename: P:\Projects\017101\02 Design\Civil\Storm Water Design\Basin Design\Basin #2\PreDevelopment_CA_1
--- Sub -Area Data ---
Name Description Reach Area(ac) RCN Tc
------------------------------------------------------------------------------
Wet Pond # Outlet 4.2 69 0.133
Total area: 4.20 (ac)
--- Storm Data --
Rainfall Depth by Rainfall Return Period
2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr
(in) (in) (in) (in) (in) (in) (in)
--------------------------------------------------------------------------------
3.67 4.71 5.55 6.74 7.72 8.75 3.03
Storm Data Source: User -provided custom storm data
Rainfall Distribution Type: Type II
Dimensionless Unit Hydrograph: <standard>
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:21:07 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Storm Data
Rainfall Depth by Rainfall Return Period
2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr
(in) (in) (in) (in) (in) (in) (in)
--------------------------------------------------------------------------------
3.67 4.71 5.55 6.74 7.72 8.75 3.03
Storm Data Source: User -provided custom storm data
Rainfall Distribution Type: Type II
Dimensionless Unit Hydrograph: <standard>
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:21:07 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Watershed Peak Table
Sub -Area
Peak Flow by
Rainfall
Return Period
or Reach
2-Yr 5-Yr
10-Yr
25-Yr 50-Yr 100-Yr 1-Yr
Identifier
----------------------------------------------------------------------------------
(cfs) (cfs)
(cfs)
(cfs) (cfs) (cfs) (cfs)
SUBAREAS
Wet Pond #
6.13 10.48
14.35
20.16 25.14 30.48 3.83
REACHES
OUTLET 6.13 10.48 14.35 20.16 25.14 30.48 3.83
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SCurry
Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Hydrograph Peak/Peak Time Table
Sub -Area
Peak
Flow and Peak Time (hr) by Rainfall Return Period
or Reach
2-Yr
5-Yr 10-Yr 25-Yr 50-Yr
100-Yr 1-Yr
Identifier
(cfs)
(cfs) (cfs) (cfs) (cfs)
(cfs) (cfs)
----------------------------------------------------------------------------------
(hr)
(hr) (hr) (hr) (hr)
(hr) (hr)
SUBAREAS
Wet Pond #
6.13
10.48 14.35 20.16 25.14
30.48 3.83
12.00
11.97 11.96 11.96 11.96
11.95 12.01
REACHES
OUTLET 6.13 10.48 14.35 20.16 25.14 30.48 3.83
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SCurry Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Summary Table
Sub -Area Drainage Time of Curve Receiving Sub -Area
Identifier Area Concentration Number Reach Description
(ac) (hr)
--------------------------------------------------------------------------------
Wet Pond # 4.20 0.133 69 Outlet
Total Area: 4.20 (ac)
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SCurry Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Time of Concentration Details
Sub -Area Flow Mannings's End Wetted Travel
Identifier/ Length Slope n Area Perimeter Velocity Time
(ft) (ft/ft) (sq ft) (ft) (ft/sec) (hr)
--------------------------------------------------------------------------------
Wet Pond #
User -provided 0.133
Time of Concentration 0.133
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SCurry Ft Bragg CA TEMF_Wet Pond
Pre -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Land Use and Curve Number Details
Sub -Area Hydrologic Sub -Area Curve
Identifier Land Use Soil Area Number
Group (ac)
--------------------------------------------------------------------------------
Wet Pond #Open space; grass cover 50% to 75% (fair) B 4.2 69
Total Area / Weighted Curve Number 4.2 69
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:21:07 PM

WinTR-55 Current Data Description
Identification Data
User: SCurry Date: 10/3/2019
Project: Ft Bragg CA TEMF_Wet Pond Units: English
SubTitle: Post -Development Wet Pond #1, Qp Areal Units: Acres
State: North Carolina
County: Cumberland NOAA-B
Filename: P:\Projects\017101\02 Design\Civil\Storm Water Design\Basin Design\Basin #2\PostDevelopment_CA_
--- Sub -Area Data ---
Name Description Reach Area(ac) RCN Tc
------------------------------------------------------------------------------
Wet Pond 1 Outlet 4.2 92 0.133
Total area: 4.20 (ac)
--- Storm Data --
Rainfall Depth by Rainfall Return Period
2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr
(in) (in) (in) (in) (in) (in) (in)
--------------------------------------------------------------------------------
3.67 4.71 5.55 6.74 7.72 8.75 3.03
Storm Data Source: User -provided custom storm data
Rainfall Distribution Type: Type II
Dimensionless Unit Hydrograph: <standard>
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:23:51 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Post -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Storm Data
Rainfall Depth by Rainfall Return Period
2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr
(in) (in) (in) (in) (in) (in) (in)
--------------------------------------------------------------------------------
3.67 4.71 5.55 6.74 7.72 8.75 3.03
Storm Data Source: User -provided custom storm data
Rainfall Distribution Type: Type II
Dimensionless Unit Hydrograph: <standard>
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:23:51 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Post -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Watershed Peak Table
Sub -Area
Peak Flow by
Rainfall
Return Period
or Reach
2-Yr 5-Yr
10-Yr
25-Yr 50-Yr 100-Yr 1-Yr
Identifier
----------------------------------------------------------------------------------
(cfs) (cfs)
(cfs)
(cfs) (cfs) (cfs) (cfs)
SUBAREAS
Wet Pond 1
16.50 22.08
26.54
32.84 37.98 43.38 13.07
REACHES
OUTLET 16.50
22.08 26.54
32.84 37.98 43.38 13.07
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SCurry
Ft Bragg CA TEMF_Wet
Pond
Post -Development Wet
Pond #1, Qp
Cumberland NOAA-B County,
North Carolina
Hydrograph Peak/Peak
Time Table
Sub -Area
Peak
Flow and Peak Time (hr)
by Rainfall Return Period
or Reach
2-Yr
5-Yr 10-Yr
25-Yr 50-Yr
100-Yr 1-Yr
Identifier
(cfs)
(cfs) (cfs)
(cfs) (cfs)
(cfs) (cfs)
----------------------------------------------------------------------------------
(hr)
(hr) (hr) (hr) (hr)
(hr) (hr)
SUBAREAS
Wet Pond 1
16.50
22.08 26.54
32.84 37.98
43.38 13.07
11.95
11.95 11.94 11.95
11.95
11.94 11.95
REACHES
OUTLET 16.50
22.08 26.54
32.84 37.98 43.38 13.07
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SCurry Ft Bragg CA TEMF_Wet Pond
Post -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Summary Table
Sub -Area Drainage Time of Curve Receiving Sub -Area
Identifier Area Concentration Number Reach Description
(ac) (hr)
--------------------------------------------------------------------------------
Wet Pond 1 4.20 0.133 92 Outlet
Total Area: 4.20 (ac)
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:23:51 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Post -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Time of Concentration Details
Sub -Area Flow Mannings's End Wetted Travel
Identifier/ Length Slope n Area Perimeter Velocity Time
(ft) (ft/ft) (sq ft) (ft) (ft/sec) (hr)
--------------------------------------------------------------------------------
Wet Pond 1
User -provided 0.133
Time of Concentration 0.133
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:23:51 PM

SCurry Ft Bragg CA TEMF_Wet Pond
Post -Development Wet Pond #1, Qp
Cumberland NOAA-B County, North Carolina
Sub -Area Land Use and Curve Number Details
Sub -Area
Hydrologic
Sub -Area
Curve
Identifier Land Use
Soil
Area
Number
--------------------------------------------------------------------------------
Group
(ac)
Wet Pond 10pen space; grass cover 50% to 75%
(fair) B
.82
69
Paved parking lots, roofs, driveways
B
3.38
98
Total Area / Weighted Curve Number
4.2
92
WinTR-55, Version 1.00.10 Page 1 10/3/2019 2:23:51 PM

Ft Bragg Civil Affairs
Stormwater Pond Volume Comparison
Revised March-2020
Wet Pond #1
Contour Intervals (ft)
NCDEQ Requirements (cf)
EISA Option #2 Requirements (cf)
Pre vs Post Development (10-yr)
Provided in Design (cf)
Volume Main Pool VMa
233-240
28,756
37,893
38,959
Volume of Forebay VFB
236-240
4,313
5,684
6,330
Design Volume Dv
240-241.50
11,805
21,249
30,501
Pre -Development = 35,502 cf
Post -Development = 73,395 cf
A = 37,893 cf

WET POND #1
SOF Civil Affairs
THE DRAINAGE AREA 1
Drainage area number
Wet Pond #1
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
sf
Parking / driveway (sq ft)
146003 sf
Total surface water area (sq ft)
sf
Sidewalk (sq ft)
sf
Total drainage area (sq ft)
182952 sf
Roof (sq ft)
1230 sf
BUA associated with existing development (sq ft)
sf
Roadway (sq ft)
sf
Proposed new BUA (sq ft)
147233 sf
Other, please specify in the comment box below (sq ft)
sf
Percent BUA of drainage area
180%
Total BUA (sq ft)
147233 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify):
Design rainfall depth (in)
1.0 in
EISA 438, ARMY LID, FORT BRAGG IDG
Minimum volume required (cu ft)
11805 cf
Design volume of SCM (cu ft)
30501 cf
GENERAL MDC FROM 02H .1050
#1 Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
#2 Is the SCM located on or near contaminated soils?
No
#8 Does the mainetenance access comply with General MDC (8)?
Yes
#3 What are the side slopes of the SCM (H:V)?
3:1
#9 Does the drainage easement comply with General MDC (9)?
Yes
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
#10 If the SCM is on a single family lot, does the plat comply with General MDC (10)?
Yes
#4 Are the inlets, outlets, and receiving stream protected from erosion (I0-yearstorm)?
Yes
#11 Is there an O&M Agreement that complies with General MDC (11)?
Yes
#5 Is there a a bypass for flows in excess of the design flaw?
Yes
#12 Is there an O&M Plan that complies with General MDC (12)?
Yes I
#6 What is the method for dewatering the SCM for maintenance?
I Other
1#13 Was the SCM designed by an NC licensed professional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
HRT
#6 Width of the vegetated shelf (feet)
6 ft
#1 Surface area of the main permanent pool (square feet)
9917 sf
#6 Location of vegetated shelf
@ Normal Pool
#1 Volume of the main permanent pool (cubic feet)
38959 cf
#6 Elevation of top of shelf (fmsl)
240 ft
#2 Average depth of the main pool (feet)
6 ft
#6 Elevation of bottom of shelf (fmsl)
239 ft
#2 Was the vegetated shelf included in the calculation of average depth?
Yes
#6 Slope of vegetated shelf (H:V)
6:1
#2 Elevation of the bottom of the permanent pool (fmsl)
234 ft
#7 Diameter of drawdown orifice (inches)
4.0 in
#2 Elevation of the top of the permanent pool (fmsl)
240 ft
#7 Drawdown time for the temporary pool (hours)
51 hrs
#2 Elevation of the top of the temporary pool (fmsl)
241.50 ft
#7 Does the orifice drawdown from below the top surface of the permanent pool?
No
#3 Depth provided for sediment storage (inches)
12 in
#8 Does the pond minimize impacts to the receiving channel from the 1-yr, 24-hr storm?
Yes
#4 Are the inlet(s) and outlet located in a manner that avoids short-circuiting?
Yes
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles, that will be taken to improve the flow path:
#9 If yes, is documentation provided per Wet Pond MDC (9)?
No
#10 Is a trash rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
6330
#11 Are the dam and embankment planted in non -clumping turf grass?
Yes
#5 Is this 15-20% of the volume in the main pool?
Yes
#11 Species of turf that will be used on the dam and embankment
Sod
#5 Depth of forebay at entrance (inches)
48 in
#11 Describe the planting plan for the vegetated shelf:
#5 Depth of forebay at exit (inches)
48 in
Contractor to provide landscape establishment to achieve 100% coverage throughout site in 12 months. Sod is desired
by the User for embankments.
#5 Does water flow out of the forebay in anon -erosive manner?
Yes
#5 Clean -out depth for forebay (inches)
12 in
#5 Will the forebay be cleaned out when the depth is reduced to less than the above?
Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review:
Project based entirely within Fort Bragg (US Gov't property). No easements required.
Wet Pond #1 1 1:49 PM 3/9/2020

Permit No.
(to be provided by DWQ)
®O�OF W ATF9QG
G
NCDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 11)) must be printed, filled out and submitted along with all of the required information.
I. PROJECT INFORMATION
Project name Fort Bragg Civil Affairs TEMF - Wet Pond #1
Contact person Stephen Curry, P.E.
Phone number 859.280.3581
Date Revised March 9, 2020
Drainage area number Wet Pond #1
II. DESIGN INFORMATION
Site Characteristics
Drainage area
182,952 ft2
Impervious area, post -development
147,233 ft2
% impervious
80.48 %
Design rainfall depth
1.0 in
Storage Volume: Non -SA Waters
Minimum volume required
Volume provided
Storage Volume: SA Waters
1.5 runoff volume
Pre -development 1-yr, 24-hr runoff
Post -development 1-yr, 24-hr runoff
Minimum volume required
Volume provided
Peak Flow Calculations
Is the pre/post control of the lyr 24hr storm peak flow required?
1-yr, 24-hr rainfall depth
Rational C, pre -development
Rational C, post -development
Rainfall intensity: 1-yr, 24-hr storm
Pre -development 1-yr, 24-hr peak flow
Post -development 1-yr, 24-hr peak flow
Pre/Post 1-yr, 24-hr peak flow control
Elevations
Temporary pool elevation
Permanent pool elevation
SHWT elevation (approx. at the perm. pool elevation)
Top of 1 Oft vegetated shelf elevation
Bottom of 1 Oft vegetated shelf elevation
Sediment cleanout, top elevation (bottom of pond)
Sediment cleanout, bottom elevation
Sediment storage provided
Is there additional volume stored above the state -required temp. pool?
Elevation of the top of the additional volume
11,805 ft3
30,501 ft3
OK, volume provided is equal to or in excess of volume required.
ft3
ft3
ft3
ft3
ft3
(Y or N)
3.1 in
0.20 (unitless)
93.00 (unitless)
2.38 in/hr OK
3.83 ft3/sec
13.07 ft3/sec
9.24 ft3/sec
241.50 fmsl
240.00 fmsl
240.00 fmsl
240.00 fmsl
241.00 fmsl Data not needed for calculation option #1, but OK if provided.
233.00 fmsl
232.00 fmsl Data not needed for calculation option #1, but OK if provided.
1.00 ft
(Y or N)
fmsl
Form SW401-Wet Detention Basin-Rev.9-4/18/12 Parts I. & II. Design Summary, Page 1 of 2

Permit No.
(to be provided by DWQ)
Surface Areas
Area, temporary pool
17,674 ft2
Area REQUIRED, permanent pool
183 ft2
SAIDA ratio
0.10 (unitless)
Area PROVIDED, permanent pool, Apen-pool
9,917 ft'
OK
Area, bottom of 1 Oft vegetated shelf, Abot shelf
8,536 ft2
Area, sediment cleanout, top elevation (bottom of pond), AW_,nd
2,513 ft'
Volumes
Volume, temporary pool
30,501 ft3
OK
Volume, permanent pool, Vpen-pool
38,959 ft3
Volume, forebay (sum of forebays if more than one forebay)
6,330 ft3
Forebay % of permanent pool volume
16.2% %
Insufficient forebay volume.
SAIDA Table Data
Design TSS removal
85 %
Coastal SAIDA Table Used?
N (Y or N)
Mountain/Piedmont SAIDA Table Used?
Y (Y or N)
SAIDA ratio
0.10 (unitless)
Average depth (used in SAIDA table):
Calculation option 1 used? (See Figure 10-2b)
Y (Y or N)
Volume, permanent pool, Vpen-pool
38,959 ft3
Area provided, permanent pool, Apef„_pooi
9,917 ft'
Average depth calculated
3.80 ft
OK
Average depth used in SAIDA, cl , (Round to nearest 0.5ft)
4.0 ft
OK
Calculation option 2 used? (See Figure 10-2b)
N (Y or N)
Area provided, permanent pool, ApQf1„_pwi
9,917 ft2
Area, bottom of 1 Oft vegetated shelf, Abot shelf
8,536 ft2
Area, sediment cleanout, top elevation (bottom of pond), Abot_pond
2,513 ft2
"Depth" (distance b/w bottom of 1Oft shelf and top of sediment)
8.00 ft
Average depth calculated
ft
Average depth used in SAIDA, day, (Round to down to nearest 0.5ft)
ft
Drawdown Calculations
Drawdown through orifice?
Y (Y or N)
Diameter of orifice (if circular)
4.00 in
Area of orifice (if -non -circular)
in
Coefficient of discharge (CD)
0.60 (unitless)
Driving head (Ho)
241.50 ft
Drawdown through weir?
N (Y or N)
Weir type
(unitless)
Coefficient of discharge (C.)
(unitless)
Length of weir (L)
ft
Driving head (H)
ft
Pre -development 1-yr, 24-hr peak flow
3.83 ft3/sec
Post -development 1-yr, 24-hr peak flow
13.07 ft3/sec
Storage volume discharge rate (through discharge orifice or weir)
0.25 ft3/sec
Storage volume drawdown time
2.10 days
OK, draws down in 2-5 days.
Additional Information
Vegetated side slopes
3 :1
OK
Vegetated shelf slope
10 :1
OK
Vegetated shelf width
10.0 ft
OK
Length of flowpath to width ratio
3 :1
OK
Length to width ratio
3.4 :1
OK
Trash rack for overflow & orifice?
Y (Y or N)
OK
Freeboard provided
1.0 ft
OK
Vegetated filter provided?
Y (Y or N)
OK
Recorded drainage easement provided?
N (Y or N)
Insufficient. Recorded drainage easement required.
Capures all runoff at ultimate build -out?
Y (Y or N)
OK
Drain mechanism for maintenance or emergencies is:
Pump
Form SW401-Wet Detention Basin-Rev.9-4/18/12 Parts I. & II. Design Summary, Page 2 of 2

Project: Ft Bragg Civil Affairs TEMF - Wet Basin #2
Date: 19-Jun-19
Rv=0.05 +0.9*IA
Rv - Runoff Coefficient
IA- Impervious fraction
Dv=3630*RD*Rv*A
Dv - Design Volume (cf)
RD - Desing Storm Depth (in)
A - Drainage Area (Ac)
Impervious Area (Ac)=
Pervious Area (Ac)=
Total Area (Ac)=
IA=
RD, Design Storm Depth (in)=
Simple Method for Runoff Volume
Rv = 0.05 + 0.9 *[A
Where: Rv = Runoff coefficient (unitless)
IA = Impervious fraction (unitless)
DV = 3630 * RD* Rv* A
Where: DV — Design volume (cu ft)
Ro = Design storm depth (in)
A = Drainage area (ac)
3.38
0.82
4.2
0.80
1.0
Rv= 0.77
Dv= 11,805 NCDEQ Minimum Design Volume

Project: Ft Bragg Civil Affairs TEMF - Wet Basin #2
Date: 19-Jun-19
Hydraullic Retention Time (HRT) Method
Dv - Design Volume (cf) From Simple Method
Dv= 11,805 cf
VMP = 28,756 cf
Equation 1: Main Pool Volume, Vmp
VMP = 0.87 * HRT * DV
5
Where: 0.87 = Factor to adjust for the volume in the forebay
vv,p = Main pool volume, not including the forebay (cubic feet)
HRT = Required hydraulic residence time (14 days)
TS = Average time between storm events (5 days)
DV = Design volume (cubic feet)

Pond No. 1 - Civil Affaris Wet Pond #1 HydraflowHydrographsExtension for Autodesk® Civil 3D®2019byAutodesk,Inc. v2019
12.00
Top of pond
EIev.243.00
10.00
16.00 ft Riser
WeirA - Elev. 241.50
20.00 ft Cipoletti weir
WeirB - Elev. 242.00
8.00
6.00
4.00
2.00
CuIvA - 35.0 LF of 24.0 in @ 1.00%
0.00
Stage (ft)
Bottom of pond
Elev. 233.00
10-yr
100-yr
5-yr
Section
NTS
50-yr
2-yr
25-yr
1-yr
Inflow hydrograph = 2. SCS Runoff - Basin #2 Post Development
Project: Basin #2 Wet Pond Design.gpw
Thursday, 10 / 3 / 2019

Pond No. 1 - Civil Affaris Wet Pond #1
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019
12.00
10.00
- 8.00
- 6.00
- 4.00
2.00
— 0.00
Stage (ft)
Elev. 233.00
Top of pond —\
EIev.243.00
10-yr
100-yr 5-yr
Front View 50-yr 2-yr
NTS - Looking Downstream
25-yr 1-yr
Inflow hydrograph = 2. SCS Runoff - Basin #2 Post Development
Project: Basin #2 Wet Pond Design.gpw I Thursday, 10 / 3 / 2019

Ft Bragg Civil Affairs - Wet Pond #1
Stormwater Pond Riser Summary
October-2019
Wet Pond #1
Storm Return Interval
(yr)
Peak Flow (Qp)
w/ Inlet Control
Maximum Elevation (ft)
w/ Inlet Control
1
0
239.77
2
0.15
240.29
5
0.32
240.76
10
0.44
241.24
25
1.67
241.57
50
5.09
241.69
100
14.02
241.98

Wet Pond #1 Drawdown Time
Ft Bragg CA TEMF
Revised: 05-March-2020
Orifice Diameter 4 inches
Discharge Rate of Orifice (cuft/s) 0.25
Volume of Stormwater for Drawdown 1 45,465
Incremental Storage (cuft):
240
11,354
241
16,437
241.50
17,674
Total Storage (cuft)
Drawdown Rate:
Volume of Stormwater / Discharge Rate
45,465
181860 sec
51 hrs
2.1 days

Wet Pond #1
Main Pond Volume Revised March202O
Project: Ft Bragg Civil Affairs
Basin Description: Wet Pond #1 Main Pond Volume
Contour
Contour
Depth
Incremental
Cumulative
Incremental
Cumulative
Elevation
Area
(ft)
Volume
Volume
Volume
Volume
(sq. ft)
Avg. End
Avg. End
Conic
Conic
(cu. ft)
(cu. ft)
(cu. ft)
(cu. ft)
233.0
1,510.0
N/A
N/A
0
N/A
0
234.0
2,513.0
1
2012
2012
1990
1990
235.0
3,587.0
1
3050
5062
3034
5024
236.0
4,734.0
1
4161
9222
4147
9172
237.0
5,945.0
1
5340
14562
5328
14500
238.0
7,212.0
1
6579
21140
6568
21068
239.0
8,536.0
1
7874
29014
7865
28933
240.0
11,354.0
1
9945
38959
9912
38844

Wet Pond #1 - Forebay
Project:
Basin Description:
Contour Contour
Elevation Area
(sq. ft)
Forebay Volume.txt
Ft Bragg Civil Affairs
Wet Pond #1 - Forebay
Depth
(ft)
236.0
774.0
N/A
237.0
1,129.0
1
238.0
1,540.0
1
239.0
2,008.0
1
240.0
2,532.0
1
Incremental
Volume
Avg. End
(cu. ft)
N/A
952
1335
1774
2270
Page 1
Cumulative
Volume
Avg. End
(cu. ft)
0
952
2286
4060
6330
Incremental
Volume
Conic
(cu. ft)
N/A
946
1329
1769
2265
Cumulative
Volume
Conic
(cu. ft)
0
946
2275
4044
6309

Design Volume.txt
Wet Pond #1 - Design Volume
Project: Ft Bragg Civil Affairs
Basin Description: Wet Pond #1 - Design Volume
Contour
Contour
Depth
Incremental
Cumulative
Incremental
Cumulative
Elevation
Area
(ft)
Volume
Volume
Volume
Volume
(sq. ft)
Avg. End
Avg. End
Conic
Conic
(cu. ft)
(cu. ft)
(cu. ft)
(cu. ft)
240.0
12,449.0
N/A
N/A
0
N/A
N/A
241.0
16,437.0
1.00
14443.00
14443.00
14396.90
14396.90
242.0
18,912.0
1.00
17674.50
32117.50
17660.04
32056.94
Page 1