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 39 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 40 Summary for Subcatchment 13S: PDA #2 - Pervious Summary for Subcatchment 14S: PDA #3 - Pervious Runoff = 0.10 cfs @ 12.11 hrs, Volume= 0.007 af, Depth= 3.23" Runoff = 0.25 cfs @ 12.16 hrs, Volume= 0.020 af, Depth= 3.23" Routed to Link 5L : POI #2 Routed to Link 6L : 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 10-Year-Current Rainfall=5.38", P2=3.47" NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Area (ac) CN Description Area (ac) CN Description 0.025 80 >75% Grass cover, Good, HSG D 0.076 80 >75% Grass cover, Good, HSG D 0.025 100.00% Pervious

0.076 80 >75% Grass cover, Good, HSG D 0.025 100.00% Pervious Area 0.076 100.00% Pervious Area Tc Length Slope Velocity Capacity Description Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) (min) (feet) (ft/ft) (ft/sec) (cfs) 1.8 8 0.0200 0.07 Sheet Flow, A-B 8.9 83 0.0400 0.15 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" Grass: Dense n= 0.240 P2= 3.47" 0.1 6 0.0150 0.73 Sheet Flow, B-C Using McCuen-Spiess flow length Smooth surfaces n= 0.011 P2= 3.47" 0.3 62 0.0540 3.49 Shallow Concentrated Flow, 1.2 5 0.0200 0.07 Sheet Flow, C-D Grassed Waterway Kv= 15.0 fps Grass: Dense n= 0.240 P2= 3.47" 9.2 145 Total 0.6 133 0.0290 3.46 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps Subcatchment 14S: PDA #3 - Pervious 3.7 152 Total

Subcatchment 14S: PDA #3 - Pervious 3.7 152 Total Hydrograph Subcatchment 13S: PDA #2 - Pervious 0.28 Runoff 0.25 cfs Hydrograph 0.26 NOAA 24-hr D 0.24 0.11 0.10 cfs Runoff 10-Year-Current Rainfall=5.38" 0.22 0.105 NOAA 24-hr D P2=3.47" 0.1 0.2 0.095 10-Year-Current

0.2 0.095 10-Year-Current Rainfall=5.38" Runoff Area=0.076 ac 0.09 0.18 P2=3.47" Runoff Volume=0.020 af 0.085 Flow (cfs) 0.16 0.08 Runoff Area=0.025 ac Runoff Depth=3.23" 0.075 0.07 Runoff Volume=0.007 af 0.14 Flow Length=145' 0.12 Tc=9.2 min Flow (cfs) 0.065 0.06 Runoff Depth=3.23" 0.055 Flow Length=152'

Runoff Depth=3.23" 0.055 Flow Length=152' 0.1 CN=80 0.05 0.08 0.045 Tc=3.7 min 0.06 0.04 CN=80 0.035 0.04 0.03 0.025 0.02 0.02 0 0.015 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 0.01 Time (hours) 0.005 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)