Analysis - Proposed Conditions NOAA 24-hr D 10 YR-F Rainfall=6.34"
Prepared by Civil Core Consulting Printed 12/19/2025
HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC Page 274
Inflow Area = 27,007 sf, 30.65% Impervious, Inflow Depth = 2.23" for 10 YR-F event
Inflow = 0.83 cfs @ 12.17 hrs, Volume= 5,011 cf
Outflow = 0.13 cfs @ 14.16 hrs, Volume= 5,011 cf, Atten= 84%, Lag= 119.3 min
Discarded = 0.13 cfs @ 14.16 hrs, Volume= 5,011 cf
Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routed to Link 33L : POA 2
Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs
Peak Elev= 93.12' @ 14.16 hrs Surf.Area= 1,156 sf Storage= 1,207 cf
Plug-Flow detention time= 86.8 min calculated for 5,011 cf (100% of inflow)
Center-of-Mass det. time= 86.8 min ( 945.7 - 858.9 )
Volume Invert Avail.Storage Storage Description
#1 91.65' 4,378 cf Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet)
91.65 520 0 0
92.00 651 205 205
93.00 1,094 873 1,077
94.00 1,629 1,362 2,439
95.00 2,249 1,939 4,378
Device Routing Invert Outlet Devices
#2 Device 3 94.70' 48.0" x 48.0" Horiz. Grate C= 0.600
#1 Device 3 93.65' 2.5" Vert. Orifice C= 0.600 Limited to weir flow at low heads
#3 Primary 93.65' 12.0" Round Culvert L= 17.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 93.65' / 93.50' S= 0.0088 /' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf
#4 Discarded 91.65' 4.950 in/hr Exfiltration over Surface area Phase-In= 0.01'
Discarded OutFlow Max=0.13 cfs @ 14.16 hrs HW=93.12' (Free Discharge)
4=Exfiltration (Exfiltration Controls 0.13 cfs)
Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=91.65' TW=0.00' (Dynamic Tailwater)
3=Culvert ( Controls 0.00 cfs)
1=Orifice ( Controls 0.00 cfs)
2=Grate ( Controls 0.00 cfs)