Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

2026-02 Proposed Conditions - AJH NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 27 Summary for Pond 1P: UG BASIN Inflow Area = 0.142 ac,100.00% Impervious, Inflow Depth = 5.14" for 10-Year-Current event Inflow = 0.80 cfs @ 12.10 hrs, Volume= 0.061 af Outflow = 0.31 cfs @ 12.13 hrs, Volume= 0.061 af, Atten= 62%, Lag= 1.7 min Primary = 0.31 cfs @ 12.13 hrs, Volume= 0.061 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= 619.58' @ 12.13 hrs Surf.Area= 0.006 ac Storage= 0.009 af Plug-Flow detention time= 9.0 min calculated for 0.061 af (100% of inflow) Center-of-Mass det. time= 9.0 min ( 752.4 - 743.4 ) 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=0.31 cfs @ 12.13 hrs HW=619.58' (Free Discharge) 1=RCP_Round 15" (Passes 0.31 cfs of 7.36 cfs potential flow) 2=Orifice (Orifice Controls 0.31 cfs @ 6.29 fps) 3=Orifice ( Controls 0.00 cfs) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)