Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 57 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Pond 41P: Basin 10 Inflow Area = 97,058 sf, 61.64% Impervious, Inflow Depth = 2.46" for 2-Year event Inflow = 4.80 cfs @ 12.18 hrs, Volume= 19,894 cf Outflow = 2.87 cfs @ 12.32 hrs, Volume= 19,894 cf, Atten= 40%, Lag= 8.2 min Discarded = 2.22 cfs @ 12.04 hrs, Volume= 19,528 cf Primary = 0.65 cfs @ 12.32 hrs, Volume= 367 cf Routed to Link 28L : POA 2 Routing by Stor-Ind method, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs Peak Elev= 576.18' @ 12.32 hrs Surf.Area= 9,583 sf Storage= 1,769 cf Plug-Flow detention time= 4.0 min calculated for 19,884 cf (100% of inflow) Center-of-Mass det. time= 4.0 min ( 786.7 - 782.7 ) Volume #1 Invert 576.00' Elevation (feet) 576.00 577.00 578.00 579.00 Avail.Storage 28,749 cf Surf.Area (sq-ft) 9,583 9,583 9,583 9,583 Device #1 Routing Primary Invert 576.15' #2 Primary 576.15' #3 Discarded 576.00' Storage Description Custom Stage Data (Prismatic) Listed below (Recalc) Inc.Store (cubic-feet) 0 9,583 9,583 9,583 Cum.Store (cubic-feet) 0 9,583 19,166 28,749 Outlet Devices 42.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads 42.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads 10.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=2.22 cfs @ 12.04 hrs HW=576.03' (Free Discharge) 3=Exfiltration (Exfiltration Controls 2.22 cfs) Primary OutFlow Max=0.62 cfs @ 12.32 hrs HW=576.18' (Free Discharge) 1=Grate (Weir Controls 0.31 cfs @ 0.61 fps) 2=Grate (Weir Controls 0.31 cfs @ 0.61 fps)