complete drainage report rev 9

POA-2 2024-05-12 HydroCad - Proposed POA 2B-1 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 175 Summary for Pond 27P: Basin 2 Inflow Area = 183,393 sf, 42.82% Impervious, Inflow Depth = 2.09" for 10-Year event Inflow = 8.13 cfs @ 12.18 hrs, Volume= 31,954 cf Outflow = 0.93 cfs @ 13.25 hrs, Volume= 22,643 cf, Atten= 89%, Lag= 64.2 min Primary = 0.93 cfs @ 13.25 hrs, Volume= 22,643 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= 545.18' @ 13.25 hrs Surf.Area= 28,204 sf Storage= 18,379 cf Plug-Flow detention time= 403.9 min calculated for 22,632 cf (71% of inflow) Center-of-Mass det. time= 300.9 min ( 1,107.1 - 806.2 ) Volume #1 Invert 544.50' Elevation (feet) 544.50 546.00 547.00 Avail.Storage 74,059 cf Surf.Area (sq-ft) 26,023 30,850 31,958 Device #1 Routing Primary Invert 545.50' #2 Primary 544.85' Storage Description Custom Stage Data (Prismatic) Listed below (Recalc) Inc.Store (cubic-feet) 0 42,655 31,404 Cum.Store (cubic-feet) 0 42,655 74,059 Outlet Devices 42.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads 1.5' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.7' Crest Height Primary OutFlow Max=0.93 cfs @ 13.25 hrs HW=545.18' (Free Discharge) 1=Grate ( Controls 0.00 cfs) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.93 cfs @ 1.98 fps) Pond 27P: Basin 2 Grate Sharp-Crested Rectangular Weir