Supporting Documentation · May 28, 2026
2026 05 Storm Water Management Report rcd 5 6 2026
ca1b6a05d93acd17db8ba3736caf854fbeada41956eb0ec8f599e95e0e23a985Indexed text
catchment 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 4.8 267 Total Runoff 2.13 cfs NOAA 24-hr D Subcatchment 2S: EDA #1 - Pervious 2 10-Year-Current Rainfall=5.38" Hydrograph P2=3.47" Runoff Runoff Area=0.377 ac 0.32 0.30 cfs Runoff Volume=0.162 af 0.3 NOAA 24-hr D Flow (cfs)
NOAA 24-hr D Flow (cfs) 0.28 Runoff Depth=5.14" 10-Year-Current Rainfall=5.38" 0.26 Flow Length=219' P2=3.47" 0.24 1 Tc=1.7 min Runoff Area=0.157 ac 0.22 CN=98 0.2 Runoff Volume=0.021 af Flow (cfs) 0.18 Runoff Depth=1.60"
0.18 Runoff Depth=1.60" 0.16 Flow Length=267' 0.14 Tc=4.8 min 0.12 CN=61 0.1 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 0.08 Time (hours) 0.06 0.04 0.02 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
56 58 60 62 64 66 68 70 72 Time (hours)
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 23 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 24 Summary for Subcatchment 3S: EDA #2 - Impervious Summary for Subcatchment 4S: EDA #2 - Pervious Runoff = 0.08 cfs @ 12.10 hrs, Volume= 0.006 af, Depth= 5.14" Runoff = 0.06 cfs @ 12.12 hrs, Volume= 0.004 af, Depth= 1.60" Routed to Link 2L : POI #2 Routed to Link 2L : POI #2 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 0.015 98 Paved parking, HSG B 0.029 61 >75% Grass cover, Good, HSG B 0.015 100.00% Impervious Area
0.029 61 >75% Grass cover, Good, HSG B 0.015 100.00% Impervious Area 0.029 100.00% 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) 0.5 42 0.0260 1.34 Sheet Flow, A-B 3.8 20 0.0200 0.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.47" Grass: Dense n= 0.240 P2= 3.47" 0.3 58 0.0300 3.52 Shallow Concentrated Flow, B-C 0.6 133 0.0290 3.46 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps Paved Kv= 20.3 fps 0.8 100 Total 4.4 153 Total Subcatchment 3S: EDA #2 - Impervious Subcatchment 4S: EDA #2 - Pervious Hydrograph Hydrograph Runoff
Runoff Runoff 0.09 0.08 cfs 0.06 0.06 cfs 0.085 NOAA 24-hr D 0.055 NOAA 24-hr D 0.08 0.075 10-Year-Current Rainfall=5.38" 0.05 10-Year-Current Rainfall=5.38" 0.07 P2=3.47" P2=3.47" 0.045 0.065 Runoff Area=0.015 ac Runoff Area=0.029 ac 0.06 0.04 Runoff Volume=0.006 af Runoff Volume=0.004 af 0.055 Flow (cfs)
Runoff Volume=0.004 af 0.055 Flow (cfs) Flow (cfs) 0.05 Runoff Depth=5.14" 0.035 Runoff Depth=1.60" 0.045 Flow Length=100' 0.03 Flow Length=153' 0.04 Tc=0.8 min 0.025 Tc=4.4 min 0.035 0.03 CN=98 0.02 CN=61 0.025 0.015 0.02 0.015 0.01 0.01 0.005 0.005 0 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 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 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) Time (hours)
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 25 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment 5S: EDA #3 - Impervious Summary for Subcatchment 6S: EDA #2 - Pervious Runoff = 0.09 cfs @ 12.15 hrs, Volume= 0.008 af, Depth= 5.14" Runoff = 0.13 cfs @ 12.17 hrs, Volume= 0.011 af, Depth= 1.60" Routed to Link 3L : POI #3 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 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 0.019 98 Unconnected pavement, HSG B 0.084 61 >75% Grass cover, Good, HSG B 0.019 100.00% Impervious Area
File revisions (1)
- Sep 29, 2026
ca1b6a05d93a18,504,890 bytes