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230550 HydroCAD
Concept HydroCAD-230550 Type II 24-hr 100-yr Rainfall=8.10"
Prepared by Lane Engineering, LLC Printed 5/26/2025
HydroCAD® 10.00-17 s/n 03788 © 2016 HydroCAD Software Solutions LLC Page 26

Summary for Pond 7P: P-2 SGW 2

Inflow Area = 0.927 ac, 53.39% Impervious, Inflow Depth > 6.89" for 100-yr event
Inflow = 8.31 cfs @ 11.98 hrs, Volume= 0.532 af
Outflow = 8.00 cfs @ 12.01 hrs, Volume= 0.467 af, Atten= 4%, Lag= 1.9 min
Primary = 5.37 cfs @ 12.02 hrs, Volume= 0.442 af
Secondary = 2.63 cfs @ 12.01 hrs, Volume= 0.025 af

Routing by Dyn-Stor-Ind method, Time Span= 0.10-24.01 hrs, dt= 0.03 hrs / 3
Peak Elev= 25.99' @ 12.01 hrs Surf.Area= 3,703 sf Storage= 6,729 cf

Plug-Flow detention time= 113.0 min calculated for 0.467 af (88% of inflow)
Center-of-Mass det. time= 54.4 min ( 829.0 - 774.6 )

Volume Invert Avail.Storage Storage Description
#1 23.85' 8,692 cf Custom Stage Data (Irregular) Listed below (Recalc)

Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area
(feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft)
23.85 2,618 200.0 0 0 2,618
26.50 3,990 239.0 8,692 8,692 4,099

Device Routing Invert Outlet Devices
#1 Primary 23.50' 15.0" Round 15" Culvert
L= 219.0' CPP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 23.50' / 23.00' S= 0.0023 '/' Cc= 0.900
n= 0.012, Flow Area= 1.23 sf
#2 Device 1 24.75' 0.9' long 0.9' notch 2 End Contraction(s)
#3 Device 1 25.85' 16.3' long WR Inlet 0 End Contraction(s)
#4 Secondary 25.90' 30.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s)
Primary OutFlow Max=5.37 cfs @ 12.02 hrs HW=25.99' TW=0.00' (Dynamic Tailwater)
1=15" Culvert (Barrel Controls 5.37 cfs @ 4.37 fps)
2=0.9' notch (Passes < 2.94 cfs potential flow)
3=WR Inlet (Passes < 2.69 cfs potential flow)

Secondary OutFlow Max=2.59 cfs @ 12.01 hrs HW=25.99' TW=0.00' (Dynamic Tailwater)
4=Sharp-Crested Rectangular Weir (Weir Controls 2.59 cfs @ 0.97 fps)

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