Page 25 - planning-committee-packet

230550 HydroCAD
Concept HydroCAD-230550 Type II 24-hr 2-yr Rainfall=3.60"
Prepared by Lane Engineering, LLC Printed 5/26/2025
HydroCAD® 10.00-17 s/n 03788 © 2016 HydroCAD Software Solutions LLC Page 6

Summary for Pond 5P: P-1 SGW 1

Inflow Area = 0.909 ac, 55.27% Impervious, Inflow Depth > 2.54" for 2-yr event
Inflow = 3.17 cfs @ 11.98 hrs, Volume= 0.192 af
Outflow = 0.10 cfs @ 14.52 hrs, Volume= 0.069 af, Atten= 97%, Lag= 152.3 min
Primary = 0.10 cfs @ 14.52 hrs, Volume= 0.069 af
Secondary = 0.00 cfs @ 0.10 hrs, Volume= 0.000 af

Routing by Dyn-Stor-Ind method, Time Span= 0.10-24.01 hrs, dt= 0.03 hrs / 3
Peak Elev= 23.92' @ 14.52 hrs Surf.Area= 6,755 sf Storage= 5,906 cf

Plug-Flow detention time= 369.7 min calculated for 0.069 af (36% of inflow)
Center-of-Mass det. time= 244.5 min ( 1,046.2 - 801.7 )

Volume Invert Avail.Storage Storage Description
#1 23.00' 13,638 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)
23.00 6,129 338.0 0 0 6,129
25.00 7,533 364.0 13,638 13,638 7,742

Device Routing Invert Outlet Devices
#1 Primary 22.50' 15.0" Round 15" Culvert
L= 50.0' CPP, square edge headwall, Ke= 0.500
Inlet / Outlet Invert= 22.50' / 22.00' S= 0.0100 '/' Cc= 0.900
n= 0.012, Flow Area= 1.23 sf
#2 Device 1 23.75' 0.5' long 6" notch 2 End Contraction(s)
#3 Device 1 24.35' 16.3' long WR Inlet 0 End Contraction(s)
#4 Secondary 24.38' 30.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s)
Primary OutFlow Max=0.10 cfs @ 14.52 hrs HW=23.92' TW=0.00' (Dynamic Tailwater)
1=15" Culvert (Passes 0.10 cfs of 5.26 cfs potential flow)
2=6" notch (Weir Controls 0.10 cfs @ 1.34 fps)
3=WR Inlet ( Controls 0.00 cfs)

Secondary OutFlow Max=0.00 cfs @ 0.10 hrs HW=23.00' TW=0.00' (Dynamic Tailwater)
4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)

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