NOAA 24-hr D 10 YR-F Rainfall=6.34" Printed 12/19/2025 ons LLC Page 244
Analysis - Proposed Conditions NOA Prepared by Civil Core Consulting HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC
Summary for Pond 5P: BIORETENTION BASIN 1A
Inflow Area = 70,567 sf, 24.69% Impervious, Inflow Depth = 1.92" for 10 YR-F event Inflow = 2.50 cfs @ 12.11 hrs, Volume = 11,283 cf Outflow = 0.27 cfs @ 13.52 hrs, Volume = 9,776 cf, Atten = 89%, Lag = 84.6 min Primary = 0.27 cfs @ 13.52 hrs, Volume = 9,776 cf Routed to Pond 2P : Subsurface Infiltration Basin 1
Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 93.74' @ 13.52 hrs Surf.Area= 1,500 sf Storage= 5,607 cf Plug-Flow detention time= 328.9 min calculated for 9,775 cf (87% of inflow) Center-of-Mass det. time= 258.1 min (1,053.5 - 795.4)
VolumeInvertAvail.StorageStorage Description
#190.00'8,250 cfCustom Stage Data (Prismatic)Listed below (Recalc)
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
90.001,50000
95.501,5008,2508,250
DeviceRoutingInvertOutlet Devices
#1Device 391.00'2.5" Vert. Orifice C = 0.600 Limited to weir flow at low heads
#2Device 395.00'48.0" x 48.0" Horiz. Grate C = 0.600 Limited to weir flow at low heads
#3Primary87.48'12.0" Round Culvert\n L = 28.0' RCP, groove end projecting, Ke = 0.200\nInlet / Outlet Invert= 87.48' / 87.00' S = 0.0171'' Cc = 0.900\n n = 0.012 Concrete pipe, finished, Flow Area= 0.79 sf
Primary OutFlow Max=0.27 cfs @ 13.52 hrs HW=93.74' TW=87.01' (Dynamic Tailwater) 3=Culvert (Passes 0.27 cfs of 10.81 cfs potential flow) 1=Orifice (Orifice Controls 0.27 cfs @ 7.81 fps) 2=Grate ( Controls 0.00 cfs)
Pond 5P: BIORETENTION BASIN 1A Orifice