Drainage Report

Basin 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 40S: Basin 2-1 Runoff = 0.79 cfs @ 12.18 hrs, Volume= 0.068 af, Depth= 1.36" Routed to Pond 41P : Pond 2-1 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) CN Description 23,447 74 >75% Grass cover, Good, HSG C 607 98 Roofs, HSG C 2,020 98 Water Surface, 0% imp, HSG C 26,074 76 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 100 0.0600 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.5 90 0.0340 2.77 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.6 190 Total, Increased to minimum Tc = 10.0 min Subcatchment 40S: Basin 2-1 Hydrograph 0.85 Runoff 0.79 cfs 0.8 0.75 NOAA 24-hr D 0.7 2-Year Rainfall=3.44" 0.65 0.6

NOAA 24-hr D 0.7 2-Year Rainfall=3.44" 0.65 0.6 Runoff Area=26,074 sf 0.55 Runoff Volume=0.068 af 0.5 Flow (cfs) 0.45 Runoff Depth=1.36" 0.4 Flow Length=190' 0.35 0.3 Tc=10.0 min 0.25 CN=76/98 0.2 0.15 0.1 0.05 0 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)