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 29 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 51S: Basin 10 - Imp Runoff = 3.77 cfs @ 12.18 hrs, Volume= Routed to Pond 41P : Basin 10 15,986 cf, Depth= 3.21" 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) 19,602 35,284 4,937 59,823 59,823 Tc (min) 9.0 1.0 0.7 10.7 CN 98 98 98 98 Description Paved parking, HSG C Roofs, HSG C Paved parking, HSG D Weighted Average 100.00% Impervious Area Length (feet) 59 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 210 0.0480 3.53 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps 110 2.50 Direct Entry, Pipe Flow (C-D) 379 Total Subcatchment 51S: Basin 10 - Imp Hydrograph 4 Flow (cfs) 3 2 Runoff 3.77 cfs NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=59,823 sf Runoff Volume=15,986 cf Runoff Depth=3.21" Flow Length=379' Tc=10.7 min CN=98 1 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)