2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" 2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Prepared by Dynamic Engineering Printed 5/5/2026 Prepared by Dynamic Engineering Printed 5/5/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 71 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 72 Summary for Pond 1P: UG BASIN Pond 1P: UG BASIN Hydrograph Inflow Area = 0.142 ac,100.00% Impervious, Inflow Depth = 8.94" for 100-Year-Current event Inflow = 1.37 cfs @ 12.10 hrs, Volume= 0.106 af 1.37 cfs Inflow Primary Outflow = 0.94 cfs @ 12.11 hrs, Volume= 0.106 af, Atten= 31%, Lag= 0.8 min Primary = 0.94 cfs @ 12.11 hrs, Volume= 0.106 af Inflow Area=0.142 ac Routed to Link 4L : POI #1 Peak Elev=620.82' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 620.82' @ 12.11 hrs Surf.Area= 0.005 ac Storage= 0.017 af

outing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 620.82' @ 12.11 hrs Surf.Area= 0.005 ac Storage= 0.017 af 0.94 cfs Storage=0.017 af 1 Plug-Flow detention time= 11.1 min calculated for 0.106 af (100% of inflow) Flow (cfs) Center-of-Mass det. time= 11.1 min ( 746.7 - 735.7 ) 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 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 n= 0.012 Concrete pipe, finished, Flow Area= 1.23 sf Time (hours) #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=0.94 cfs @ 12.11 hrs HW=620.82' (Free Discharge) 1=RCP_Round 15" (Passes 0.94 cfs of 11.85 cfs potential flow) 2=Orifice (Orifice Controls 0.41 cfs @ 8.27 fps) 3=Orifice (Orifice Controls 0.54 cfs @ 2.74 fps) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)