Analysis - Proposed Conditions NOAA 24-hr D 100 YR-C Rainfall=9.48" Prepared by Civil Core Consulting Printed 12/19/2025 HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC Page 345
Summary for Pond 33P: INFILTRATION BASIN 2
Inflow Area =27,007 sf,30.65% Impervious,Inflow Depth = 4.08" for 100 YR-C event
Inflow =1.85 cfs @12.18 hrs,Volume= 9,185 cf
Outflow =0.29 cfs @13.23 hrs,Volume= 9,185 cf,Atten= 84%, Lag= 62.8 min
Discarded =0.20 cfs @13.23 hrs,Volume= 8,204 cf
Primary =0.10 cfs @13.23 hrs,Volume= 981 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= 94.12' @ 13.23 hrs Surf.Area= 1,704 sf Storage= 2,640 cf
Plug-Flow detention time= 125.5 min calculated for 9,185 cf (100% of inflow) Center-of-Mass det. time= 125.5 min ( 974.6 - 849.1 )
VolumeInvertAvail.StorageStorage Description
#191.65'4,378 cfCustom Stage Data (Prismatic)Listed below (Recalc)
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
91.6552000
92.00651205205
93.001,0948731,077
94.001,6291,3622,439
95.002,2491,9394,378
DeviceRoutingInvertOutlet Devices
#1Device 393.65'2.5" Vert. Orifice C= 0.600 Limited to weir flow at low heads
#2Device 394.70'48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads
#3Primary93.65'12.0" 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
#4Discarded91.65'4.950 in/hr Exfiltration over Surface area Phase-In= 0.01'
Discarded OutFlow Max=0.20 cfs @ 13.23 hrs HW=94.12' (Free Discharge) 4=Exfiltration (Exfiltration Controls 0.20 cfs)
Primary OutFlow Max=0.10 cfs @ 13.23 hrs HW=94.12' TW=0.00' (Dynamic Tailwater) 3=Culvert (Passes 0.10 cfs of 0.76 cfs potential flow) 1=Orifice (Orifice Controls 0.10 cfs @ 2.92 fps) 2=Grate ( Controls 0.00 cfs)