1240815StormWaterManagementReportrcd 3 12 2026

512-516 Pleasant Valley Way, West Orange 1240815-pipes3-C NOAA 24-hr D 25-Year-2020 Rainfall=6.72", P2=3.47" Prepared by Casey & Keller, Inc Printed 2/4/2026 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Pond 3: Pervious Pavers Inflow Area = 0.176 ac, 86.88% Impervious, Inflow Depth = 6.13" for 25-Year-2020 event Inflow = 1.20 cfs @ 12.06 hrs, Volume= 0.090 af Outflow = 0.41 cfs @ 12.18 hrs, Volume= 0.090 af, Atten= 66%, Lag= 7.0 min Discarded = 0.11 cfs @ 11.20 hrs, Volume= 0.078 af Primary = 0.30 cfs @ 12.18 hrs, Volume= 0.011 af Routed to Pond 5 : Pipes Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 414.86' @ 12.18 hrs Surf.Area= 1,620 sf Storage= 879 cf Plug-Flow detention time= 34.7 min calculated for 0.090 af (100% of inflow) Center-of-Mass det. time= 34.6 min ( 781.7 - 747.0 ) Volume Invert Avail.Storage Storage Description #1 413.50' 1,730 cf 60.00'W x 27.00'L x 2.67'H STONE & PAVERS 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 Discarded OutFlow Max=0.11 cfs @ 11.20 hrs HW=413.53' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.30 cfs @ 12.18 hrs HW=414.86' (Free Discharge) 2=Culvert (Barrel Controls 0.30 cfs @ 2.81 fps) 49