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 273 Summary for Pond 22P: Basin 4 Inflow Area = 49,050 sf, 84.66% Impervious, Inflow Depth = 7.97" for 100-Year event Inflow = 9.06 cfs @ 12.12 hrs, Volume= 32,597 cf Outflow = 1.94 cfs @ 12.43 hrs, Volume= 32,597 cf, Atten= 79%, Lag= 18.4 min Discarded = 1.13 cfs @ 11.48 hrs, Volume= 28,845 cf Primary = 0.81 cfs @ 12.43 hrs, Volume= 3,752 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= 573.49' @ 12.43 hrs Surf.Area= 12,197 sf Storage= 7,284 cf Plug-Flow detention time= 24.8 min calculated for 32,581 cf (100% of inflow) Center-of-Mass det. time= 24.7 min ( 773.8 - 749.0 ) 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 @ 11.48 hrs HW=572.03' (Free Discharge) 3=Exfiltration (Exfiltration Controls 1.13 cfs) Primary OutFlow Max=0.81 cfs @ 12.43 hrs HW=573.49' (Free Discharge) 1=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Orifice (Orifice Controls 0.81 cfs @ 4.15 fps) Pond 22P: Basin 4 Sharp-Crested Rectangular Weir Orifice Exfiltration