2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing Conditi NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" 2026-04 Proposed & Existing Conditi NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 13 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 14 Summary for Pond 2P: BIO BASIN Pond 2P: BIO BASIN Hydrograph Inflow Area = 0.146 ac, 53.42% Impervious, Inflow Depth = 2.48" for 2-Year-Current event Inflow = 0.40 cfs @ 12.10 hrs, Volume= 0.030 af 0.40 cfs Inflow Primary Outflow = 0.24 cfs @ 12.12 hrs, Volume= 0.022 af, Atten= 40%, Lag= 0.9 min 0.44 Primary = 0.24 cfs @ 12.12 hrs, Volume= 0.022 af 0.42 0.4 Inflow Area=0.146 ac Routed to Link 4L : POI #1

Inflow Area=0.146 ac Routed to Link 4L : POI #1 0.38 0.36 Peak Elev=623.12' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs 0.34 Peak Elev= 623.12' @ 12.12 hrs Surf.Area= 625 sf Storage= 525 cf 0.32 Storage=525 cf 0.3 0.28 0.24 cfs Plug-Flow detention time= 200.7 min calculated for 0.022 af (72% of inflow) 0.26 Flow (cfs) Center-of-Mass det. time= 97.0 min ( 878.0 - 781.0 ) 0.24 0.22 0.2 Volume Invert Avail.Storage Storage Description 0.18 #1 622.00' 1,219 cf Custom Stage Data (Prismatic)Listed below (Recalc) 0.16 0.14 0.12 Elevation Surf.Area Inc.Store Cum.Store 0.1 (feet) (sq-ft) (cubic-feet) (cubic-feet)

n Surf.Area Inc.Store Cum.Store 0.1 (feet) (sq-ft) (cubic-feet) (cubic-feet) 0.08 0.06 622.00 323 0 0 0.04 623.00 577 450 450 0.02 624.00 960 769 1,219 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 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 Limited to weir flow at low heads Primary OutFlow Max=0.24 cfs @ 12.12 hrs HW=623.12' (Free Discharge) 1=Culvert (Passes 0.24 cfs of 12.21 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.24 cfs @ 1.68 fps) 3=Grate ( Controls 0.00 cfs)