complete drainage report rev 9

POA-2 2024-05-12 HydroCad - Proposed POA 2B-1 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 71 Summary for Pond 27P: Basin 2 Inflow Area = 183,393 sf, 42.82% Impervious, Inflow Depth = 1.15" for 2-Year event Inflow = 4.44 cfs @ 12.18 hrs, Volume= 17,565 cf Outflow = 0.19 cfs @ 15.96 hrs, Volume= 8,254 cf, Atten= 96%, Lag= 226.9 min Primary = 0.19 cfs @ 15.96 hrs, Volume= 8,254 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= 544.96' @ 15.96 hrs Surf.Area= 27,516 sf Storage= 12,418 cf Plug-Flow detention time= 632.5 min calculated for 8,254 cf (47% of inflow) Center-of-Mass det. time= 488.9 min ( 1,305.8 - 816.8 ) 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=0.19 cfs @ 15.96 hrs HW=544.96' (Free Discharge) 1=Grate ( Controls 0.00 cfs) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.19 cfs @ 1.13 fps) Pond 27P: Basin 2 Grate Sharp-Crested Rectangular Weir