2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CondiNOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" 2026-04 Proposed & Existing CondiNOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" 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 27 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 28 Pond 1P: UG BASIN Summary for Pond 2P: BIO BASIN Hydrograph Inflow Area = 0.146 ac, 53.42% Impervious, Inflow Depth = 3.05" for 2-Year-Projected event 0.61 cfs Inflow Inflow = 0.50 cfs @ 12.10 hrs, Volume= 0.037 af Primary 0.65 Outflow = 0.33 cfs @ 12.11 hrs, Volume= 0.029 af, Atten= 34%, Lag= 0.6 min 0.6 Inflow Area=0.142 ac Primary = 0.33 cfs @ 12.11 hrs, Volume= 0.029 af Routed to Link 4L : POI #1 0.55 Peak

Routed to Link 4L : POI #1 0.55 Peak Elev=619.12' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs 0.5 Storage=0.006 af Peak Elev= 623.19' @ 12.11 hrs Surf.Area= 650 sf Storage= 567 cf 0.45 0.4 Plug-Flow detention time= 178.5 min calculated for 0.029 af (77% of inflow) Flow (cfs) 0.35 Center-of-Mass det. time= 85.7 min ( 863.5 - 777.8 ) 0.3 0.26 cfs Volume Invert Avail.Storage Storage Description 0.25 #1 622.00' 1,219 cf Custom Stage Data (Prismatic)Listed below (Recalc) 0.2 0.15 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 0.1 622.00 323 0 0 0.05

622.00 323 0 0 0.05 623.00 577 450 450 0 624.00 960 769 1,219 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 Time (hours) Device Routing Invert Outlet Devices #1 Primary 619.05' 15.0" Round Culvert L= 35.0' RCP, rounded edge headwall, Ke= 0.100 Inlet / Outlet Invert= 619.05' / 618.93' S= 0.0034 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 622.86' 0.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 623.70' 48.0" x 48.0" Horiz. Grate C= 0.600

#3 Device 1 623.70' 48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.33 cfs @ 12.11 hrs HW=623.19' (Free Discharge) 1=Culvert (Passes 0.33 cfs of 12.34 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.33 cfs @ 1.88 fps) 3=Grate ( Controls 0.00 cfs)