Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 117 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Pond 21P: Basin 3 Inflow Area = 51,670 sf, 62.76% Impervious, Inflow Depth = 4.07" for 10-Year event Inflow = 4.59 cfs @ 12.15 hrs, Volume= 17,540 cf Outflow = 3.95 cfs @ 12.20 hrs, Volume= 17,540 cf, Atten= 14%, Lag= 3.1 min Discarded = 1.21 cfs @ 11.88 hrs, Volume= 15,267 cf Primary = 2.74 cfs @ 12.20 hrs, Volume= 2,272 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= 559.58' @ 12.20 hrs Surf.Area= 5,227 sf Storage= 1,206 cf Plug-Flow detention time= 2.4 min calculated for 17,531 cf (100% of inflow) Center-of-Mass det. time= 2.4 min ( 775.6 - 773.3 ) Volume #1 Invert 559.00' Elevation (feet) 559.00 560.00 561.00 561.17 Device #1 #2 Avail.Storage 4,537 cf Surf.Area (sq-ft) 5,227 5,227 5,227 5,227 Routing Primary Discarded Invert 559.22' 559.00' Storage Description Custom Stage Data (Prismatic) Listed below 11,343 cf Overall x 40.0% Voids Inc.Store (cubic-feet) 0 5,227 5,227 889 Cum.Store (cubic-feet) 0 5,227 10,454 11,343 Outlet Devices 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 10.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=1.21 cfs @ 11.88 hrs HW=559.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 1.21 cfs) Primary OutFlow Max=2.70 cfs @ 12.20 hrs HW=559.57' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 2.70 cfs @ 1.95 fps)