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 127 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Pond 27P: Basin 2 Inflow Area = 217,925 sf, 51.70% Impervious, Inflow Depth = 1.90" for 10-Year event Inflow = 10.85 cfs @ 12.19 hrs, Volume= 34,595 cf Outflow = 1.51 cfs @ 12.85 hrs, Volume= 16,342 cf, Atten= 86%, Lag= 39.6 min Primary = 1.51 cfs @ 12.85 hrs, Volume= 16,342 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= 544.77' @ 12.85 hrs Surf.Area= 27,872 sf Storage= 20,640 cf Plug-Flow detention time= 300.1 min calculated for 16,333 cf (47% of inflow) Center-of-Mass det. time= 173.5 min ( 972.3 - 798.8 ) Volume #1 Invert 544.00' Elevation (feet) 544.00 546.00 Avail.Storage 56,873 cf Surf.Area (sq-ft) 26,023 30,850 Device #1 Routing Primary Invert 545.10' #2 Primary 544.68' Storage Description Custom Stage Data (Prismatic) Listed below (Recalc) Inc.Store (cubic-feet) 0 56,873 Cum.Store (cubic-feet) 0 56,873 Outlet Devices 42.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads 18.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.7' Crest Height Primary OutFlow Max=1.50 cfs @ 12.85 hrs HW=544.77' (Free Discharge) 1=Grate ( Controls 0.00 cfs) 2=Sharp-Crested Rectangular Weir (Weir Controls 1.50 cfs @ 0.97 fps)