1240815StormWaterManagementReportrcd 3 12 2026

512-516 Pleasant Valley Way, West Orange 1240815-pipes3-C Water Quality Storm Water Quality Rainfall=1.25", 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 5: Pipes Inflow Area = 0.343 ac, 76.01% Impervious, Inflow Depth = 0.34" for Water Quality event Inflow = 0.33 cfs @ 1.07 hrs, Volume= 0.010 af Outflow = 0.27 cfs @ 1.13 hrs, Volume= 0.010 af, Atten= 19%, Lag= 3.8 min Discarded = 0.03 cfs @ 0.80 hrs, Volume= 0.005 af Primary = 0.24 cfs @ 1.13 hrs, Volume= 0.005 af Routed to Link 7 : Proposed Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 411.28' @ 1.13 hrs Surf.Area= 400 sf Storage= 140 cf Plug-Flow detention time= 20.0 min calculated for 0.010 af (100% of inflow) Center-of-Mass det. time= 20.0 min ( 88.6 - 68.6 ) Volume Invert Avail.Storage Storage Description #1 410.50' 329 cf 10.00'W x 40.00'L x 3.00'H STONE 1,200 cf Overall - 377 cf Embedded = 823 cf x 40.0% Voids #2 411.00' 377 cf 24.0" Round Pipe Storage x 3 Inside #1 L= 40.0' S= 0.0020 '/' 706 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 410.50' 2.900 in/hr Exfiltration over Surface area #2 Primary 411.00' 12.0" Round Culvert L= 14.0' Ke= 0.100 Inlet / Outlet Invert= 411.00' / 410.94' S= 0.0043 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf #3 Device 2 411.00' 8.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 2 413.90' 24.0" x 24.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.03 cfs @ 0.80 hrs HW=410.54' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.23 cfs @ 1.13 hrs HW=411.27' (Free Discharge) 2=Culvert (Barrel Controls 0.23 cfs @ 2.00 fps) 3=Orifice

ree Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.23 cfs @ 1.13 hrs HW=411.27' (Free Discharge) 2=Culvert (Barrel Controls 0.23 cfs @ 2.00 fps) 3=Orifice (Passes 0.23 cfs of 0.24 cfs potential flow) 4=Grate ( Controls 0.00 cfs) 129