2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" 2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", 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 43 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 44 Summary for Pond 2P: BIO BASIN Pond 2P: BIO BASIN Hydrograph Inflow Area = 0.146 ac, 53.42% Impervious, Inflow Depth = 4.25" for 10-Year-Current event Inflow = 0.69 cfs @ 12.10 hrs, Volume= 0.052 af 0.69 cfs Inflow Primary Outflow = 0.47 cfs @ 12.11 hrs, Volume= 0.043 af, Atten= 32%, Lag= 0.7 min 0.75 Primary = 0.47 cfs @ 12.11 hrs, Volume= 0.043 af 0.7 Inflow Area=0.146 ac Routed to Link 4L : POI #1 0.65 0.6

0.6 Peak Elev=623.29' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 623.29' @ 12.11 hrs Surf.Area= 686 sf Storage= 630 cf 0.55 0.47 cfs Storage=630 cf 0.5 Plug-Flow detention time= 148.2 min calculated for 0.043 af (83% of inflow) 0.45 Flow (cfs) Center-of-Mass det. time= 72.4 min ( 845.1 - 772.7 ) 0.4 0.35 Volume Invert Avail.Storage Storage Description 0.3 #1 622.00' 1,219 cf Custom Stage Data (Prismatic)Listed below (Recalc) 0.25 0.2 Elevation Surf.Area Inc.Store Cum.Store 0.15 (feet) (sq-ft) (cubic-feet) (cubic-feet) 0.1 622.00 323 0 0

feet) 0.1 622.00 323 0 0 623.00 577 450 450 0.05 624.00 960 769 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=0.47 cfs @ 12.11 hrs HW=623.29' (Free Discharge) 1=Culvert (Passes 0.47 cfs of 12.54 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.47 cfs @ 2.13 fps) 3=Grate ( Controls 0.00 cfs)