1240815StormWaterManagementReport

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", 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 = 8.60" for 100-Year-2020 event Inflow = 1.58 cfs @ 12.06 hrs, Volume= 0.120 af Outflow = 0.74 cfs @ 12.15 hrs, Volume= 0.120 af, Atten= 53%, Lag= 5.6 min Discarded = 0.11 cfs @ 10.90 hrs, Volume= 0.094 af Primary = 0.64 cfs @ 12.15 hrs, Volume= 0.027 af Routed to Pond 5 : Pipes Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 415.25' @ 12.15 hrs Surf.Area= 1,620 sf Storage= 1,132 cf Plug-Flow detention time= 32.8 min calculated for 0.120 af (100% of inflow) Center-of-Mass det. time= 32.7 min ( 774.5 - 741.8 ) 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 @ 10.90 hrs HW=413.53' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.64 cfs @ 12.15 hrs HW=415.24' (Free Discharge) 2=Culvert (Barrel Controls 0.64 cfs @ 3.23 fps) 40