Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 27 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 46S: Basin 11 - Perv Runoff = 0.56 cfs @ 12.18 hrs, Volume= Routed to Pond 33P : Basin 11 2,043 cf, Depth= 1.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) 2,920 16,544 19,464 19,464 Tc (min) 8.9 Length (feet) 83 0.9 150 9.8 233 CN 80 74 75 Description >75% Grass cover, Good, HSG D >75% Grass cover, Good, HSG C Weighted Average 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0400 0.15 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" Using McCuen-Spiess flow length 0.0330 2.92 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps Total Subcatchment 46S: Basin 11 - Perv Hydrograph Runoff 0.6 0.56 cfs 0.55 0.5 0.45 Flow (cfs) 0.4 0.35 0.3 0.25 0.2 0.15 NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=19,464 sf Runoff Volume=2,043 cf Runoff Depth=1.26" Flow Length=233' Tc=9.8 min CN=75 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 74 76 78 80 Time (hours)