2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CoNOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" 2026-04 Proposed & Existing CoNOAA 24-hr D 100-Year-Projected Rainfall=11.52", 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 51 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 52 Summary for Subcatchment 4S: EDA #2 - Pervious Summary for Subcatchment 5S: EDA #3 - Impervious Runoff = 0.23 cfs @ 12.12 hrs, Volume= 0.015 af, Depth= 6.31" Runoff = 0.20 cfs @ 12.15 hrs, Volume= 0.018 af, Depth=11.28" Routed to Link 2L : POI #2 Routed to Link 3L : POI #3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs NOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" NOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" Area (ac) CN Description Area (ac) CN Description 0.029 61 >75% Grass cover, Good, HSG B 0.019 98 Unconnected pavement, HSG B 0.029 100.00% Pervious Area

0.019 98 Unconnected pavement, HSG B 0.029 100.00% Pervious Area 0.019 100.00% Impervious Area 0.019 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) Tc Length Slope Velocity Capacity Description 3.5 20 0.0200 0.10 Sheet Flow, A-B (min) (feet) (ft/ft) (ft/sec) (cfs) Grass: Dense n= 0.240 P2= 4.09" 0.2 9 0.0200 0.96 Sheet Flow, A-B 0.6 133 0.0290 3.46 Shallow Concentrated Flow, B-C Smooth surfaces n= 0.011 P2= 4.09" Paved Kv= 20.3 fps 7.9 91 0.0540 0.19 Sheet Flow, B-C 4.1 153 Total Grass: Dense n= 0.240 P2= 4.09" 0.0 7 0.0540 3.49 Shallow Concentrated Flow, C-D Subcatchment 4S: EDA #2 - Pervious Grassed Waterway Kv= 15.0 fps

Grassed Waterway Kv= 15.0 fps 8.1 107 Total Hydrograph 0.25 Runoff Subcatchment 5S: EDA #3 - Impervious 0.23 cfs 0.24 Hydrograph 0.23 NOAA 24-hr D 0.22 0.21 100-Year-Projected Rainfall=11.52" Runoff 0.21 0.20 cfs 0.2 P2=4.09" 0.2 0.19 Runoff Area=0.029 ac 0.19 NOAA 24-hr D 0.18 0.17 Runoff Volume=0.015 af 0.18 100-Year-Projected Rainfall=11.52" 0.16

0.18 100-Year-Projected Rainfall=11.52" 0.16 0.17 P2=4.09" 0.15 Runoff Depth=6.31" 0.16 Flow (cfs) 0.14 Flow Length=153' Runoff Area=0.019 ac 0.15 0.13 Runoff Volume=0.018 af 0.12 Tc=4.1 min 0.14 0.11 CN=61 0.13 Runoff Depth=11.28" Flow (cfs) 0.1 0.12 Flow Length=107' 0.09 0.11 0.08

0.11 0.08 0.1 Tc=8.1 min 0.07 CN=98 0.09 0.06 0.05 0.08 0.04 0.07 0.03 0.06 0.02 0.05 0.01 0.04 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 0.03 Time (hours) 0.02 0.01

0.01 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)