complete drainage report rev 9

POA-2 2024-05-12 HydroCad - Proposed POA 2B-1 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 267 Summary for Pond 21P: Basin 3 Inflow Area = 21,910 sf, 31.15% Impervious, Inflow Depth = 6.42" for 100-Year event Inflow = 3.21 cfs @ 12.15 hrs, Volume= 11,728 cf Outflow = 2.36 cfs @ 12.23 hrs, Volume= 11,728 cf, Atten= 26%, Lag= 4.6 min Discarded = 1.21 cfs @ 12.00 hrs, Volume= 10,971 cf Primary = 1.15 cfs @ 12.23 hrs, Volume= 756 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= 559.42' @ 12.23 hrs Surf.Area= 5,227 sf Storage= 876 cf Plug-Flow detention time= 2.2 min calculated for 11,722 cf (100% of inflow) Center-of-Mass det. time= 2.2 min ( 792.7 - 790.5 ) 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 @ 12.00 hrs HW=559.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 1.21 cfs) Primary OutFlow Max=1.13 cfs @ 12.23 hrs HW=559.42' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.13 cfs @ 1.45 fps) Pond 21P: Basin 3 Sharp-Crested Rectangular Weir Exfiltration