Stormwater Report

512-516 Pleasant Valley Way, West Orange 1240815-pipes Water Quality Storm Water Quality Rainfall=1.25", 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 50 Summary for Pond 5: Pipes Inflow Area = 0.360 ac, 72.63% Impervious, Inflow Depth= 0.33" for Water Quality event Inflow = 0.33 cfs @ 1.07 hrs, Volume= 0.010 af Outflow = 0.26cfs@ 1.14 hrs, Volume= 0.010 af, Atten= 22%, Lag= 4.2 min Discarded = 0.03 cfs @ 0.80 hrs, Volume= 0.005 af Primary = 0.23 cfs@ 1.14 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= 412.30'@ 1.14 hrs Surf.Area= 400 sf Storage= 145 cf Plug-Flow detention time= 19.9 min calculated for 0.010 af (100% of inflow) Center-of-Mass det. time= 19.9 min ( 88.7 - 68.8 ) Volume Invert Avail.Storage Storage Description #1 411.50! 329 cf 10.00'W x 40.00'L x 3.00'H Prismatoid 1,200 cf Overall - 377 cf Embedded = 823 cf x 40.0% Voids #2 412.00' 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 411.50’ 2,900 in/hr Exfiltration over Surface area #2~=~— Primary 412.00' 12.0" Round Culvert L=14.0' Ke=0.100 Inlet / Outlet Invert= 412.00'/ 411.94" S=0.0043'/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf #3 © Device 2 412.00' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 ~=Device 2 414.00' 24.0" x 24.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads jiscarded OutFlow Max=0.03 cfs @ 0.80 hrs HW=411.54' (Free Discharge) 4=Exfiltration (Exfiltration Controls 0.03 cfs) Rrimary OutFlow Max=0.22 cfs @ 1.14 hrs HW=412.30' (Free Discharge) ulvert (Passes 0.22 cfs of 0.27 cfs potential flow) 3=Orifice (Orifice Controls 0.22 cfs @ 1.85 fps) =Grate ( Controls 0.00 cfs) 57