complete drainage report rev 9

POA-3 2024-05-12 HydroCad - Proposed POA 3B 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 8 Summary for Subcatchment 28S: Basin 12 - Imp Runoff = 0.20 cfs @ 12.11 hrs, Volume= Routed to Pond 29P : Basin 12 0.015 af, Depth= 3.21" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) 2,500 2,500 CN 98 Description Paved parking, HSG C 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 50 0.1200 0.22 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.2 60 0.1200 5.20 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 4.0 110 Total Sheet Flow (A-B) Subcatchment 28S: Basin 12 - Imp Subcatchment 28S: Basin 12 - Imp Flow (cfs) Hydrograph 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Runoff 0.20 cfs NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=2,500 sf Runoff Volume=0.015 af Runoff Depth=3.21" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=98 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)