2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" 2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", 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 1S: EDA #1 - Impervious Summary for Subcatchment 2S: EDA #1 - Pervious Runoff = 3.64 cfs @ 12.10 hrs, Volume= 0.281 af, Depth= 8.94" Runoff = 0.85 cfs @ 12.12 hrs, Volume= 0.057 af, Depth= 4.37" Routed to Link 1L : POI #1 Routed to Link 1L : POI #1 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-Current Rainfall=9.18", P2=3.47" NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Area (ac) CN Description Area (ac) CN Description 0.377 98 Paved parking, HSG B 0.157 61 >75% Grass cover, Good, HSG B 0.377 100.00% Impervious Area

0.157 61 >75% Grass cover, Good, HSG B 0.377 100.00% Impervious Area 0.157 100.00% 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) 1.5 100 0.0100 1.09 Sheet Flow, A-B 4.0 34 0.0500 0.14 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.47" Grass: Dense n= 0.240 P2= 3.47" 0.2 119 0.0400 10.53 12.92 Pipe Channel, B-C 0.5 124 0.0410 4.11 Shallow Concentrated Flow, B-C 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' Paved Kv= 20.3 fps n= 0.013 Corrugated PE, smooth interior 0.1 13 0.0030 2.69 2.11 Pipe Channel, C-D 1.7 219 Total 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Concrete pipe, finished Subcatchment 1S: EDA #1 - Impervious 0.2 96 0.0144 6.84 8.40 Pipe Channel, D-E

bcatchment 1S: EDA #1 - Impervious 0.2 96 0.0144 6.84 8.40 Pipe Channel, D-E 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' Hydrograph n= 0.012 Concrete pipe, finished 4 4.8 267 Total Runoff 3.64 cfs NOAA 24-hr D Subcatchment 2S: EDA #1 - Pervious 100-Year-Current Rainfall=9.18" Hydrograph 3 P2=3.47" 0.95 Runoff Runoff Area=0.377 ac 0.9 0.85 cfs Runoff Volume=0.281 af 0.85 NOAA 24-hr D

0.85 NOAA 24-hr D Runoff Depth=8.94" 0.8 Flow (cfs) 100-Year-Current Rainfall=9.18" 0.75 2 Flow Length=219' P2=3.47" 0.7 Tc=1.7 min 0.65 Runoff Area=0.157 ac CN=98 0.6 Runoff Volume=0.057 af 0.55 Runoff Depth=4.37" Flow (cfs) 1 0.5

Flow (cfs) 1 0.5 0.45 Flow Length=267' 0.4 Tc=4.8 min 0.35 CN=61 0.3 0 0.25 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) 0.2 0.15 0.1 0.05 0

0.05 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)