Stormwater Report

512-516 Pleasant Valley Way, West Orange 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 8/25/2025 HydroCAD® 10.20-7a_s/n 03272 © 2025 HydroCAD Software Solutions LLC Page 33 Summary for Pond 3: Pervious Pavers Inflow Area = 0.168 ac, 91.47% Impervious, Inflow Depth = 8.69" for 100-Year-2020 event Inflow = 1.59 cfs @ 12.06 hrs, Volume= 0.121 af Outflow = 0.75 cfs@ 12.15 hrs, Volume= 0.121 af, Atten= 53%, Lag= 5.6 min Discarded = 0.11 cfs@ 10.85 hrs, Volume= 0.094 af Primary = 0.64 cfs @ 12.15 hrs, Volume= 0.027 af Routed to Pond 5 : Pipes Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 415.26'@ 12.15 hrs Surf.Area= 1,620 sf Storage= 1,140 cf Plug-Flow detention time= 32.6 min calculated for 0.121 af (100% of inflow) Center-of-Mass det. time= 32.6 min ( 772.8 - 740.2 ) Volume Invert Avail.Storage Storage Description #1 413.50' 1,730 cf 60.00'W x 27.00'L x 2.67'H Prismatoid 4,325 cf Overall x 40.0% Voids Device Routing Invert__ Outlet Devices #1 ~~ Discarded 413.50' 2.900 in/hr Exfiltration over Surface area #2~=~—- Primary 414.50' 6.0" Round Culvert L=50.0' Ke= 0.200 Inlet / Outlet Invert= 414.50'/ 414.17' S= 0.0066 '/ Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.20 sf iscarded OutFlow Max=0.11 cfs @ 10.85 hrs HW=413.53' (Free Discharge) 41=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.64 cfs @ 12.15 hrs HW=415.26' (Free Discharge) *_2=Culvert (Barrel Controls 0.64 cfs @ 3.27 fps) 40