Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

2026-02 Proposed Conditions - NOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 57 Summary for Pond 1P: UG BASIN Inflow Area = 0.142 ac,100.00% Impervious, Inflow Depth = 11.28" for 100-Year-Projected event Inflow = 1.73 cfs @ 12.10 hrs, Volume= 0.134 af Outflow = 1.36 cfs @ 12.11 hrs, Volume= 0.134 af, Atten= 21%, Lag= 0.6 min Primary = 1.36 cfs @ 12.11 hrs, Volume= 0.134 af Routed to Link 2L : POI #1 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 621.44' @ 12.11 hrs Surf.Area= 0.003 ac Storage= 0.019 af Plug-Flow detention time= 10.9 min calculated for 0.134 af (100% of inflow) Center-of-Mass det. time= 10.9 min ( 744.1 - 733.1 ) Volume Invert Avail.Storage Storage Description #1 617.75' 0.020 af 48.0" Round Pipe Storage L= 70.0' Device Routing Invert Outlet Devices #1 Primary 617.75' 15.0" Round RCP_Round 15" L= 15.0' RCP, rounded edge headwall, Ke= 0.100 Inlet / Outlet Invert= 617.75' / 617.55' S= 0.0133 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 1.23 sf #2 Device 1 617.75' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 620.25' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 621.45' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=1.36 cfs @ 12.11 hrs HW=621.44' (Free Discharge) 1=RCP_Round 15" (Passes 1.36 cfs of 13.52 cfs potential flow) 2=Orifice (Orifice Controls 0.45 cfs @ 9.09 fps) 3=Orifice (Orifice Controls 0.91 cfs @ 4.66 fps) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)