1240815StormWaterManagementReportrcd 3 12 2026

512-516 Pleasant Valley Way, West Orange 1240815-pipes3-C NOAA 24-hr D 10-Year-2020 Rainfall=5.38", 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 = 2.17" for 10-Year-2020 event Inflow = 0.81 cfs @ 12.06 hrs, Volume= 0.062 af Outflow = 0.74 cfs @ 12.09 hrs, Volume= 0.062 af, Atten= 10%, Lag= 1.8 min Discarded = 0.03 cfs @ 9.85 hrs, Volume= 0.032 af Primary = 0.71 cfs @ 12.09 hrs, Volume= 0.030 af Routed to Link 7 : Proposed Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 411.52' @ 12.09 hrs Surf.Area= 400 sf Storage= 204 cf Plug-Flow detention time= 14.7 min calculated for 0.062 af (100% of inflow) Center-of-Mass det. time= 14.6 min ( 778.8 - 764.1 ) 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 @ 9.85 hrs HW=410.53' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.69 cfs @ 12.09 hrs HW=411.51' (Free Discharge) 2=Culvert (Passes 0.69 cfs of 0.76 cfs potential flow)

(Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.69 cfs @ 12.09 hrs HW=411.51' (Free Discharge) 2=Culvert (Passes 0.69 cfs of 0.76 cfs potential flow) 3=Orifice (Orifice Controls 0.69 cfs @ 2.43 fps) 4=Grate ( Controls 0.00 cfs) 38