Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 202 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Pond 22P: Basin 4 Inflow Area = 57,587 sf, 86.93% Impervious, Inflow Depth = 8.04" for 100-Year event Inflow = 10.70 cfs @ 12.12 hrs, Volume= 38,587 cf Outflow = 2.14 cfs @ 12.47 hrs, Volume= 38,587 cf, Atten= 80%, Lag= 21.3 min Discarded = 1.13 cfs @ 11.28 hrs, Volume= 32,714 cf Primary = 1.01 cfs @ 12.47 hrs, Volume= 5,873 cf Routed to Pond 27P : Basin 2 Routing by Stor-Ind method, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs Peak Elev= 573.90' @ 12.47 hrs Surf.Area= 12,197 sf Storage= 9,247 cf Plug-Flow detention time= 29.5 min calculated for 38,568 cf (100% of inflow) Center-of-Mass det. time= 29.5 min ( 777.2 - 747.7 ) Volume #1 Invert 572.00' Elevation (feet) 572.00 573.00 574.00 574.91 Device #1 #2 #3 Avail.Storage 14,197 cf Surf.Area (sq-ft) 12,197 12,197 12,197 12,197 Routing Primary Primary Discarded Invert 574.00' 572.50' 572.00' Storage Description Custom Stage Data (Prismatic) Listed below 35,493 cf Overall x 40.0% Voids Inc.Store (cubic-feet) 0 12,197 12,197 11,099 Cum.Store (cubic-feet) 0 12,197 24,394 35,493 Outlet Devices 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads 4.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=1.13 cfs @ 11.28 hrs HW=572.03' (Free Discharge) 3=Exfiltration (Exfiltration Controls 1.13 cfs) Primary OutFlow Max=1.01 cfs @ 12.47 hrs HW=573.90' (Free Discharge) 1=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Orifice (Orifice Controls 1.01 cfs @ 5.15 fps)