Revised Stormwater Management Report

POA 1 proposed 2024-05-12 HydroCad - Proposed POA 1 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 3 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 15S: Basin 1 - Perv Runoff = 3.18 cfs @ 12.23 hrs, Volume= Routed to Pond 16P : Basin 1 13,249 cf, Depth= 1.39" 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) 65,014 49,690 114,704 114,704 Tc (min) 9.0 Length (feet) 59 1.7 425 3.4 14.1 516 1,000 CN 80 74 77 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) 0.0200 0.11 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" Using McCuen-Spiess flow length 0.0650 4.10 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps 2.50 Direct Entry, Pipe Flow (C-D) Total Subcatchment 15S: Basin 1 - Perv Hydrograph Runoff 3.18 cfs Flow (cfs) 3 2 1 0 0 2 4 NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=114,704 sf Runoff Volume=13,249 cf Runoff Depth=1.39" Flow Length=1,000' Tc=14.1 min CN=77 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)