1240815StormWaterManagementReport

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 2-Year-2020 Rainfall=3.47", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Pond 3: Pervious Pavers Inflow Area = 0.168 ac, 88.61% Impervious, Inflow Depth = 3.01" for 2-Year-2020 event Inflow = 0.57 cfs @ 12.06 hrs, Volume= 0.042 af Outflow = 0.11 cfs @ 11.75 hrs, Volume= 0.042 af, Atten= 81%, Lag= 0.0 min Discarded = 0.11 cfs @ 11.75 hrs, Volume= 0.042 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 5 : Pipes Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 414.04' @ 12.36 hrs Surf.Area= 1,620 sf Storage= 347 cf Plug-Flow detention time= 16.5 min calculated for 0.042 af (100% of inflow) Center-of-Mass det. time= 16.5 min ( 773.5 - 757.0 ) 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 Discarded OutFlow Max=0.11 cfs @ 11.75 hrs HW=413.53' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=413.50' (Free Discharge) 2=Culvert ( Controls 0.00 cfs) 14