NOAA 24-hr D 100 YR-C Rainfall=9.48" Printed 12/19/2025 tions LLC Page 339
Analysis - Proposed Conditions Prepared by Civil Core Consulting HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC
Summary for Pond 15P: PERVIOUS PAVEMENT 3B
Intflow Area = 8,712 sf,100.00% Impervious, Inflow Depth = 9.24" for 100 YR-C event Inflow = 1.65 cfs @ 12.12 hrs, Volume= 6,708 cf Outflow = 1.53 cfs @ 12.15 hrs, Volume= 6,704 cf, Atten= 7%, Lag= 1.5 min Primary = 1.53 cfs @ 12.15 hrs, Volume= 6,704 cf Routed to Pond 8P : INFILTRATION BASIN 3 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 94.89' @ 12.15 hrs Surf.Area= 8,889 sf Storage= 1,076 cf Plug-Flow detention time= 66.6 min calculated for 6,703 cf (100% of inflow) Center-of-Mass det. time= 66.5 min ( 807.5 - 741.0 )
VolumeInvertAvail.StorageStorage Description
#193.80'593 cfStone Storage Bed (Prismatic)Listed below (Recalc) 1,482 cf Overall × 40.0% Voids
#294.30'222 cfSurface and Base Course (Prismatic)Listed below (Recalc) 1,482 cf Overall × 15.0% Voids
#394.80'1,482 cfSurface (Prismatic)Listed below (Recalc)
2,296 cfTotal Available Storage
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
93.802,96300
94.302,9631,4821,482
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
94.302,96300
94.802,9631,4821,482
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
94.802,96300
95.302,9631,4821,482
DeviceRoutingInvertOutlet Devices
#1Device 393.80'2.5" Vert. Orifice C = 0.600
#2Device 394.80'48.0" x 48.0" Horiz. Grate C = 0.600
#3Primary92.00'12.0" Round Culvert L = 52.0' RCP, groove end projecting, Ke = 0.200Inlet / Outlet Invert= $ 92.00'/90.75' $ S = 0.0240'/' Cc = 0.900n=0.011, Flow Area=0.79 sf
Primary OutFlow Max=1.53 cfs @ 12.15 hrs HW=94.89' TW=91.28' (Dynamic Tailwater) 3=Culvert (Passes 1.53 cfs of 7.25 cfs potential flow) 1=Orifice (Orifice Controls 0.16 cfs @ 4.78 fps) 2=Grate (Weir Controls 1.37 cfs @ 0.97 fps)