20230912_ESC

�2J
ENGINEERING & ENVIRONMENTAL SCIENCE COMPANY
3008 ANDERSON DRIVE,SUITE 102
RALEIGH,NO 27609
[phone]
August 11, 2023
Mr. Robert Brown
Toisnot Preserve LLC
3204 Nash St.,North, Suite C
Wilson,NC 27896
RE: Erosion Control Evaluation
Toisnot Pit
NC HWY 111
Stantonsburg,NC
Dear Mr. Brown:
Attached are the calculations for the sizing of the four (4) sediment basins. The basin
surface area was based on 10-year rain frequency, although due to the relatively flat
topography, the water surface area will be larger than the basin design. The outlet
structure design was based on the 25-year rain frequency. As mining progresses it is
likely that no stormwater discharges will occur.
Approximately 0.1 cubic yards if concrete will be need for anchoring the riser pipe.
Please contact me if you have any questions
Sincerely,
T. Patrick Shilline, P. E. ; Esslii� ,:,
President
SEAL
15472
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Seasonally High Hydrologic
Soil Symbol Soil Name Groundwater Table Group
AaA Altavista 1.5'-2.5' C
Bb Bibb 0.5'-1.5' C
NoB Norfolk 4.0'-6.0' B
ENGINEERING 8 ENVIRONMENTAL
StA
State 4.0'-6.0' B SCIENCE COMPANY
Tarboro >6.0' A 3008 ANDERSON DR.,SUITE 102
Ta6 RALEIGH,NORTH CAROLINA 27609
WaB Wagram >6.0' A [phone]
Wk Wilbanks 0.0'-1.0' D
DATE:
USDA Soil Survey
osrosn3
Toisnot Pit
Wilson County, NC

(is v 1P
Watershed #1 Basin #1
Subcat Reach A Link Routing Diagram for Basin#1
Prepared by E2S
HydroCAD®10,00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC

Basin #1 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCAD@ 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 1S: Watershed #1
Runoff = 13.20 cfs @ 14.28 hrs, Volume= 4.755 af, Depth= 1.50"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type Il 24-hr 2 yr Rainfall=3.59"
Area (ac) CN Description
17.000 86 Newly graded area, HSG B
21.100 70 Woods, Good, HSG C
38.100 77 Weighted Average
38.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
67.2 100 0.0010 0.02 Sheet Flow, Sheet
Woods: Light underbrush n= 0.400 P2= 3.59"
104.4 1,980 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Unti lied Kv= 10.0 fps
171.6 2,080 Total

Basin #1 Type 1124-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 3
Summary for Pond 1 P: Basin #1
Inflow Area = 38.100 ac, 0.00% Impervious, Inflow Depth = 1.50" for 2 yr event
Inflow = 13.20 cfs @ 14.28 hrs, Volume= 4.755 of
Outflow = 0.11 cfs @ 12.70 hrs, Volume= 0.979 af, Atten= 99%, Lag= 0.0 min
Primary = 0.11 cfs @ 12.70 hrs, Volume= 0.979 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 101.63' @ 28.40 hrs Surf.Area= 195,749 sf Storage=200,338 cf
Plug-Flow detention time=3,167.5 min calculated for 0.979 of(21% of inflow)
Center-of-Mass det. time=2,973.3 min ( 3,970.5 -997.2 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 526,849 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 14,792 0 0
101.00 150,282 82,537 82,537
102.00 222,156 186,219 268,756
103.00 294,030 258,093 526,849
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12"CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n=0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18" CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3" Skimmer
#4 Primary 102.50' 10' Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=0.11 cfs @ 12.70 hrs HW=100.05' (Free Discharge)
1=12" CMP Barrel (Passes 0.11 cfs of 1.83 cfs potential flow)
JL218"CMP Riser ( Controls 0.00 cfs)
3=3"Skimmer (Constant Controls 0.11 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #1 Type/1 24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 1 S: Watershed #1
Runoff = 28.18 cfs @ 14.12 hrs, Volume= 9.836 af, Depth= 3.10"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10 yr Rainfall=5.56"
Area (ac) CN Description
17.000 86 Newly graded area, HSG B
21.100 70 Woods, Good, HSG C
38.100 77 Weighted Average
38.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
67.2 100 0.0010 0.02 Sheet Flow, Sheet
Woods: Light underbrush n= 0.400 P2= 3.59"
104.4 1,980 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
171.6 2,080 Total

IF
Basin #1 Type 11 24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Pond 1 P: Basin #1
Inflow Area = 38.100 ac, 0.00% Impervious, Inflow Depth = 3.10" for 10 yr event
Inflow = 28.18 cfs @ 14.12 hrs, Volume= 9.836 of
Outflow = 2.70 cfs @ 22.07 hrs, Volume= 4.155 af, Atten= 90%, Lag= 476.7 min
Primary = 2.70 cfs @ 22.07 hrs, Volume= 4.155 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 102.30' @ 22.07 hrs Surf.Area=244,050 sf Storage= 347,374 cf
Plug-Flow detention time= 1,358.5 min calculated for 4.153 of(42% of inflow)
Center-of-Mass det. time= 1,205.2 min ( 2,181.4-976.2 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 526,849 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 14,792 0 0
101.00 150,282 82,537 82,537
102.00 222,156 186,219 268,756
103.00 294,030 258,093 526,849
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'198.50' S= 0.0100'I' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18" CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3"Skimmer
#4 Primary 102.50' 10'Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=2.70 cfs @ 22.07 hrs HW=102.30' (Free Discharge)
1=12"CMP Barrel (Passes 2.70 cfs of 3.80 cfs potential flow)
t2=18"CMP Riser (Weir Controls 2.59 cfs @ 1.80 fps)
3=3"Skimmer (Constant Controls 0.11 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #1 Type 1124-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment IS: Watershed #1
Runoff = 39.55 cfs @ 14.11 hrs, Volume= 13.719 af, Depth= 4.32"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 yr Rainfall=6.95"
Area (ac) CN Description
17.000 86 Newly graded area, HSG B
21.100 70 Woods, Good, HSG C
38.100 77 Weighted Average
38.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (fUft) (ft/sec) (cfs)
67.2 100 0.0010 0.02 Sheet Flow, Sheet
Woods: Light underbrush n= 0.400 P2= 3.59"
104.4 1,980 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
171.6 2,080 Total

Basin #1 Type 1124-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Pond 1 P: Basin #1
Inflow Area = 38.100 ac, 0.00% Impervious, Inflow Depth = 4.32" for 25 yr event
Inflow = 39.55 cfs @ 14.11 hrs, Volume= 13.719 of
Outflow = 5.77 cfs @ 19.35 hrs, Volume= 7.996 af, Atten= 85%, Lag= 314.5 min
Primary = 5.77 cfs @ 19.35 hrs, Volume= 7.996 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 102.64' @ 19.35 hrs Surf.Area= 268,075 sf Storage=433,647 cf
Plug-Flow detention time= 1,003.7 min calculated for 7.996 of(58% of inflow)
Center-of-Mass det. time= 874.6 min ( 1,841.3-966.7 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 526,849 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 14,792 0 0
101.00 150,282 82,537 82,537
102.00 222,156 186,219 268,756
103.00 294,030 258,093 526,849
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12"CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18" CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3"Skimmer
#4 Primary 102.50' 10'Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height (feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=5.77 cfs @ 19.35 hrs HW=102.64' (Free Discharge)
1=12"CMP Barrel (Barrel Controls 4.02 cfs @ 5.12 fps)
�__2=118"CMP Riser (Passes < 6.80 cfs potential flow)
3=3"Skimmer (Passes < 0.11 cfs potential flow)
4=10' Secondary Spillway (Weir Controls 1.75 cfs @ 1.16 fps)

(2S)
2P
Watershed #2 Basin #2
Subcat Reach on Link Routing Diagram for Basin#2
Prepared by E2S
FyclroCAM)10.00-26 sln 07329 ©2020 HydroCAD Software Solutions LLC

Basin #2 Type I!24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 2S: Watershed #2
Runoff = 16.38 cfs @ 12.54 hrs, Volume= 2.378 af, Depth= 2.18"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span=0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2 yr Rainfall=3.59"
Area (ac) CN Description
13.100 86 Newly graded area, HSG B
13.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (fUft) (ft/sec) (cfs)
3.8 100 0.0200 0.43 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
50.6 960 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare& Until led Kv= 10.0 fps
54.4 1,060 Total

Basin #2 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 3
Summary for Pond 2P: Basin #2
Inflow Area = 13.100 ac, 0.00% Impervious, Inflow Depth = 2.18" for 2 yr event
Inflow = 16.38 cfs @ 12.54 hrs, Volume= 2.378 of
Outflow = 0.11 cfs @ 10.90 hrs, Volume= 1.002 af, Atten= 99%, Lag= 0.0 min
Primary = 0.11 cfs @ 10.90 hrs, Volume= 1.002 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 101.27' @ 25.06 hrs Surf.Area= 125,895 sf Storage= 97,407 cf
Plug-Flow detention time=3,162.3 min calculated for 1.001 of(42% of inflow)
Center-of-Mass det. time= 3,036.0 min ( 3,895.4-859.4)
Volume Invert Avail.Storage Storage Description
#1 100.00, 436,498 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 13,122 0 0
101.00 101,930 57,526 57,526
102.00 189,486 145,708 203,234
103.00 277,042 233,264 436,498
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S=0.0100'/' Cc= 0.900
n=0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Honz. 18" CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3"Skimmer
#4 Primary 102.50' 10'Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height (feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=0.11 cfs @ 10.90 hrs HW=100.04' (Free Discharge)
1=12" CMP Barrel (Passes 0.11 cfs of 1.82 cfs potential flow)
�__2=18"CMP Riser ( Controls 0.00 cfs)
3=3"Skimmer (Constant Controls 0.11 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #2 Type 1124-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 2S: Watershed #2
Runoff = 29.87 cfs @ 12.53 hrs, Volume= 4.359 af, Depth= 3.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10 yr Rainfall=5.56"
Area (ac) CN Description
13.100 86 Newly graded area, HSG B
13.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 100 0.0200 0.43 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
50.6 960 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
54.4 1,060 Total

Basin #2 Type //24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Pond 2P: Basin #2
Inflow Area = 13.100 ac, 0.00% Impervious, Inflow Depth = 3.99" for 10 yr event
Inflow = 29.87 cfs @ 12.53 hrs, Volume= 4.359 of
Outflow = 0.11 cfs @ 8.80 hrs, Volume= 1.021 af, Atten= 100%, Lag= 0.0 min
Primary = 0.11 cfs @ 8.80 hrs, Volume= 1.021 of
Routing by Stor-Ind method, Time Span=0.00-120.00 hrs, dt=0.05 hrs
Peak Elev= 101.86' @ 25.24 hrs Surf.Area= 177,186 sf Storage= 182,764 cf
Plug-Flow detention time= 3,144.6 min calculated for 1.021 of(23% of inflow)
Center-of-Mass det. time= 2,988.3 min ( 3,830.6 -842.2 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 436,498 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 13,122 0 0
101.00 101,930 57,526 57,526
102.00 189,486 145,708 203,234
103.00 277,042 233,264 436,498
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S=0.0100'/' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3" Skimmer
#4 Primary 102.50' 10'Secondary Spillway, C=3.27
Offset (feet) 0.00 4.50 14.50 19.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=0.11 cfs @ 8.80 hrs HW=100.04' (Free Discharge)
1=12" CMP Barrel (Passes 0.11 cfs of 1.82 cfs potential flow)
�__2=18" CMP Riser ( Controls 0.00 cfs)
3=3"Skimmer (Constant Controls 0.11 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #2 Type //24-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 2S: Watershed #2
Runoff = 39.52 cfs @ 12.52 hrs, Volume= 5.805 af, Depth= 5.32"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 yr Rainfall=6.95"
Area (ac) CN Description
13.100 86 Newly graded area, HSG B
13.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
3.8 100 0.0200 0.43 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
50.6 960 0.0010 0.32 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
54.4 1,060 Total

Basin #2 Type 1124-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Pond 2P: Basin #2
Inflow Area = 13.100 ac, 0.00% Impervious, Inflow Depth = 5.32" for 25 yr event
Inflow = 39.52 cfs @ 12.52 hrs, Volume= 5.805 of
Outflow = 0.77 cfs @ 24.53 hrs, Volume= 1.748 af, Atten= 98%, Lag= 720.6 min
Primary = 0.77 cfs @ 24.53 hrs, Volume= 1.748 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 102.12' @ 24.53 hrs Surf.Area= 200,204 sf Storage=231,788 cf
Plug-Flow detention time=2,225.5 min calculated for 1.747 of(30% of inflow)
Center-of-Mass det. time=2,078.8 min ( 2,913.0 -834.2 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 436,498 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 13,122 0 0
101.00 101,930 57,526 57,526
102.00 189,486 145,708 203,234
103.00 277,042 233,264 436,498
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12"CMP Barrel
L=50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n=0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.110 cfs 3" Skimmer
#4 Primary 102.50' 10' Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=0.77 cfs @ 24.53 hrs, HW=102.12' (Free Discharge)
1=12" CMP Barrel (Passes 0.77 cfs of 3.68 cfs potential flow)
2=18" CMP Riser (Weir Controls 0.66 cfs @ 1.14 fps)
3=3" Skimmer (Constant Controls 0.11 cfs)
4=10'Secondary Spillway ( Controls 0.00 cfs)

(3S
Watershed #3 Basin #3
SUbCat Reach On Link Routing Diagram for Basin#3
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC

Basin #3 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Pacie 2
Summary for Subcatchment 3S: Watershed #3
Runoff = 39.63 cfs @ 12.41 hrs, Volume= 4.919 af, Depth= 2.18"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2 yr Rainfall=3.59"
Area (ac) CN Description
27.100 86 Newly graded area, HSG B
27.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.7 100 0.0050 0.25 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
37.1 1,407 0.0040 0.63 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare& Untilled Kv= 10.0 fps
43.8 1,507 Total

Basin #3 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 @ 2020 HydroCAD Software Solutions LLC Page 3
Summary for Pond 3P: Basin #3
Inflow Area = 27.100 ac, 0.00% Impervious, Inflow Depth = 2.18" for 2 yr event
Inflow = 39.63 cfs @ 12.41 hrs, Volume= 4.919 of
Outflow = 0.23 cfs @ 10.50 hrs, Volume= 2.101 af, Atten=99%, Lag= 0.0 min
Primary = 0.23 cfs @ 10.50 hrs, Volume= 2.101 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 101.57' @ 24.85 hrs Surf.Area= 192,003 sf Storage= 201,321 cf
Plug-Flow detention time= 3,159.5 min calculated for 2.100 of(43% of inflow)
Center-of-Mass det. time=3,035.7 min ( 3,885.3-849.6 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 530,974 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 31,752 0 0
101.00 158,123 94,938 94,938
102.00 218,018 188,071 283,008
103.00 277,913 247,966 530,974
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L=50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n=0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4" Skimmer
#4 Primary 102.50' 10' Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height (feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=0.23 cfs @ 10.50 hrs HW=100.04' (Free Discharge)
1=12" CMP Barrel (Passes 0.23 cfs of 1.82 cfs potential flow)
2-18"CMP Riser ( Controls 0.00 cfs)
3=4" Skimmer (Constant Controls 0.23 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #3 Type /I 24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 3S: Watershed #3
Runoff = 72.15 cfs @ 12.40 hrs, Volume= 9.017 af, Depth= 3.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10 yr Rainfall=5.56"
Area (ac) CN Description
27.100 86 Newly graded area, HSG B
27.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.7 100 0.0050 0.25 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
37.1 1,407 0.0040 0.63 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
43.8 1,507 Total

Basin #3 Type 11 24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Pond 3P: Basin #3
Inflow Area = 27.100 ac, 0.00% Impervious, Inflow Depth = 3.99" for 10 yr event
Inflow = 72.15 cfs @ 12.40 hrs, Volume= 9.017 of
Outflow = 1.73 cfs @ 22.51 hrs, Volume= 3.867 af, Atten= 98%, Lag= 606.2 min
Primary = 1.73 cfs @ 22.51 hrs, Volume= 3.867 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 102.21' @ 22.51 hrs Surf.Area=230,661 sf Storage= 335,351 cf
Plug-Flow detention time=2,064.3 min calculated for 3.865 of(43% of inflow)
Center-of-Mass det. time= 1,941.6 min ( 2,774.0- 832.4 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 530,974 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 31,752 0 0
101.00 158,123 94,938 94,938
102.00 218,018 188,071 283,008
103.00 277,913 247,966 530,974
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12"CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke=0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n=0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4" Skimmer
#4 Primary 102.50' 10' Secondary Spillway, C=3.27
Offset (feet) 0.00 4.50 14.50 19.00
Height (feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=1.72 cfs @ 22.51 hrs HW=102.21' (Free Discharge)
1=12" CMP Barrel (Passes 1.72 cfs of 3.74 cfs potential flow)
L2=18" CMP Riser (Weir Controls 1.49 cfs @ 1.50 fps)
3=4"Skimmer (Constant Controls 0.23 cfs)
4=10' Secondary Spillway ( Controls 0.00 cfs)

Basin #3 Type 11 24-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 3S: Watershed #3
Runoff = 95.27 cfs @ 12.40 hrs, Volume= 12.009 af, Depth= 5.32"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt=0.05 hrs
Type II 24-hr 25 yr Rainfall=6.95"
Area (ac) CN Description
27.100 86 Newly graded area, HSG B
27.100 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftlft) (ft/sec) (cfs)
6.7 100 0.0050 0.25 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
37.1 1,407 0.0040 0.63 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
43.8 1,507 Total

Basin #3 Type //24-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Pond 3P: Basin #3
Inflow Area = 27.100 ac, 0.00% Impervious, Inflow Depth = 5.32" for 25 yr event
Inflow = 95.27 cfs @ 12.40 hrs, Volume= 12.009 of
Outflow = 3.90 cfs @ 17.29 hrs, Volume= 6.792 af, Atten= 96%, Lag= 293.5 min
Primary = 3.90 cfs @ 17.29 hrs, Volume= 6.792 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 102.44' @ 17.29 hrs Surf.Area=244,659 sf Storage= 393,303 cf
Plug-Flow detention time= 1,398.4 min calculated for 6.789 of(57% of inflow)
Center-of-Mass det. time= 1,289.5 min ( 2,113.9-824.4)
Volume Invert Avail.Storage Storage Description
#1 100.00, 530,974 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 31,752 0 0
101.00 158,123 94,938 94,938
102.00 218,018 188,071 283,008
103.00 277,913 247,966 530,974
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18" CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4"Skimmer
#4 Primary 102.50' 10' Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 14.50 19.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=3.90 cfs @ 17.29 hrs HW=102.44' (Free Discharge)
1=12"CMP Barrel (Barrel Controls 3.90 cfs @ 4.96 fps)
T--2=18"CMP Riser (Passes < 4.57 cfs potential flow)
3=4"Skimmer (Passes < 0.23 cfs potential flow)
4=10' Secondary Spillway ( Controls 0.00 cfs)

(4S > 4P
Watershed #4 Basin #4
Subcat Reach on Link Routing Diagram for Basin#4
Prepared by E2S
FHydroC7A10,00-26 sfn 07329 0 2020 HydroCAD Software Solutions LLC

Basin #4 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 4S: Watershed #4
Runoff = 41.58 cfs @ 12.74 hrs, Volume= 7.170 af, Depth= 2.18"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type 11 24-hr 2 yr Rainfall=3.59"
Area (ac) CN Description
39.500 86 Newly graded area, HSG B
39.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.6 100 0.0020 0.17 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
59.2 1,944 0.0030 0.55 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
68.8 2,044 Total

Basin #4 Type //24-hr 2 yr Rainfall=3.59"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 3
Summary for Pond 4P: Basin #4
Inflow Area = 39.500 ac, 0.00% Impervious, Inflow Depth = 2.18" for 2 yr event
Inflow = 41.58 cfs @ 12.74 hrs, Volume= 7.170 of
Outflow = 4.07 cfs @ 15.75 hrs, Volume= 5.849 af, Atten= 90%, Lag= 180.4 min
Primary = 4.07 cfs @ 15.75 hrs, Volume= 5.849 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt=0.05 hrs
Peak Elev= 102.70' @ 15.75 hrs Surf.Area= 113,566 sf Storage=202,172 cf
Plug-Flow detention time= 1,353.6 min calculated for 5.847 of(82% of inflow)
Center-of-Mass det. time= 1,276.7 min ( 2,149.5-872.7 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 371,586 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 33,800 0 0
101.00 63,421 48,611 48,611
102.00 92,913 78,167 126,778
103.00 122,404 107,659 234,436
104.00 151,895 137,150 371,586
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke= 0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100 '/' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4"Skimmer
#4 Primary 102.70' 30'Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 34.50 39.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=4.06 cfs @ 15.75 hrs HW=102.70' (Free Discharge)
1=12"CMP Barrel (Barrel Controls 4.06 cfs @ 5.17 fps)
T--2=18"
CMP Riser (Passes < 7.12 cfs potential flow)
3=4" Skimmer (Passes < 0.23 cfs potential flow)
4=30' Secondary Spillway (Weir Controls 0.00 cfs @ 0.06 fps)

Basin #4 Type //24-hr 10 yr Rainfaii=5.56"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 4S: Watershed #4
Runoff = 75.88 cfs @ 12.73 hrs, Volume= 13.143 af, Depth= 3.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10 yr Rainfall=5.56"
Area (ac) CN Description
39.500 86 Newly graded area, HSG B
39.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.6 100 0.0020 0.17 Sheet Flow, Sheet
Fallow n=0.050 P2= 3.59"
59.2 1,944 0.0030 0.55 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Until led Kv= 10.0 fps
68.8 2,044 Total

Basin #4 Type //24-hr 10 yr Rainfall=5.56"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Pond 4P: Basin #4
Inflow Area = 39.500 ac, 0.00% Impervious, Inflow Depth = 3.99" for 10 yr event
Inflow = 75.88 cfs @ 12.73 hrs, Volume= 13.143 of
Outflow = 40.05 cfs @ 13.36 hrs, Volume= 11.783 af, Atten=47%, Lag=37.9 min
Primary = 40.05 cfs @ 13.36 hrs, Volume= 11.783 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 103.20' @ 13.36 hrs Surf.Area= 128,197 sf Storage= 261,375 cf
Plug-Flow detention time=741.1 min calculated for 11.783 of(90% of inflow)
Center-of-Mass det. time=688.4 min ( 1,544.0-855.5 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 371,586 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 33,800 0 0
101.00 63,421 48,611 48,611
102.00 92,913 78,167 126,778
103.00 122,404 107,659 234,436
104.00 151,895 137,150 371,586
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12" CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke=0.900
Inlet/Outlet Invert= 99.00'/98.50' S=0.0100 '/' Cc=0.900
n= 0.025 Corrugated metal, Flow Area= 0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C= 0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4"Skimmer
#4 Primary 102.70' 30' Secondary Spillway, C=3.27
Offset(feet) 0.00 4.50 34.50 39.00
Height (feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=40.00 cfs @ 13.36 hrs HW=103.20' (Free Discharge)
1=12" CMP Barrel (Barrel Controls 4.37 cfs @ 5.56 fps)
2=18" CMP Riser (Passes < 9.31 cfs potential flow)
3=4"Skimmer (Passes < 0.23 cfs potential flow)
4=30' Secondary Spillway (Weir Controls 35.64 cfs @ 2.18 fps)

Basin #4 Type /I 24-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCADO 10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 4S: Watershed #4
Runoff = 100.23 cfs @ 12.72 hrs, Volume= 17.504 af, Depth= 5.32"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 yr Rainfall=6.95"
Area (ac) CN Description
_ 39.500 86 Newly graded area, HSG B
39.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
_ (min) (feet) (ft/ft) (ft/sec) (cfs)
9.6 100 0.0020 0.17 Sheet Flow, Sheet
Fallow n= 0.050 P2= 3.59"
59.2 1,944 0.0030 0.55 Shallow Concentrated Flow, Shallow Concent.
Nearly Bare & Untilled Kv= 10.0 fps
68.8 2,044 Total

Basin #4 Type //24-hr 25 yr Rainfall=6.95"
Prepared by E2S
HydroCAD®10.00-26 s/n 07329 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Pond 4P: Basin #4
Inflow Area = 39.500 ac, 0.00% Impervious, Inflow Depth = 5.32" for 25 yr event
Inflow = 100.23 cfs @ 12.72 hrs, Volume= 17.504 of
Outflow = 70.56 cfs @ 13.15 hrs, Volume= 16.125 af, Atten= 30%, Lag=25.5 min
Primary = 70.56 cfs @ 13.15 hrs, Volume= 16.125 of
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 103.44' @ 13.15 hrs Surf.Area= 135,358 sf Storage= 294,680 cf
Plug-Flow detention time= 566.1 min calculated for 16.125 of(92% of inflow)
Center-of-Mass det. time= 523.4 min ( 1,370.9-847.5 )
Volume Invert Avail.Storage Storage Description
#1 100.00, 371,586 cf Custom Stage Data(Prismatic)Listed below
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
100.00 33,800 0 0
101.00 63,421 48,611 48,611
102.00 92,913 78,167 126,778
103.00 122,404 107,659 234,436
104.00 151,895 137,150 371,586
Device Routing Invert Outlet Devices
#1 Primary 99.00' 12.0" Round 12"CMP Barrel
L= 50.0' CMP, projecting, no headwall, Ke=0.900
Inlet/Outlet Invert= 99.00'/98.50' S= 0.0100'/' Cc= 0.900
n= 0.025 Corrugated metal, Flow Area=0.79 sf
#2 Device 1 102.00' 18.0" Horiz. 18"CMP Riser C=0.600
Limited to weir flow at low heads
#3 Device 1 100.00' 0.230 cfs 4"Skimmer
#4 Primary 102.70' 30' Secondary Spillway, C=3.27
Offset (feet) 0.00 4.50 34.50 39.00
Height(feet) 1.50 0.00 0.00 1.50
Primary OutFlow Max=70.55 cfs @ 13.15 hrs HW=103.44' (Free Discharge)
1=12" CMP Barrel (Barrel Controls 4.51 cfs @ 5.74 fps)
1_72=18" CMP Riser (Passes < 10.21 cfs potential flow)
3=4" Skimmer (Passes < 0.23 cfs potential flow)
4=30' Secondary Spillway (Weir Controls 66.04 cfs @ 2.59 fps)

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