Supporting Documentation · Apr 15, 2026
Stormwater Management Report Revised as of 01282026 4936 0314 8685 v2
f6777d506bee83c79ba913bab178b45234e55066fd88f20823a02a45d6fdf50bIndexed text
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 51 Summary for Subcatchment P1-I: P1 IMPERVIOUS PARKING Runoff = 2.24 cfs @ 12.01 hrs, Volume= 14,881 cf, Depth= 8.94" Routed to Link 11L : Proposed Disturbed Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description * 19,976 98 Uncovered Paved parking, HSG C 19,976 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0150 1.12 Sheet Flow, sheet flow Parking area n= 0.013 P2= 3.47" 0.9 127 0.0150 2.49 Shallow Concentrated Flow, parking area Paved Kv= 20.3 fps 0.3 198 0.0449 12.08 14.83 Pipe Channel, Pipe flow 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 2.7 425 Total
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 52 Subcatchment P1-I: P1 IMPERVIOUS PARKING Hydrograph Runoff 2.24 cfs NOAA 24-hr D 2 100-Year-2020 Rainfall=9.18" P2=3.47" Runoff Area=19,976 sf Runoff Volume=14,881 cf Flow (cfs) Runoff Depth=8.94" Flow Length=425' 1 Tc=2.7 min CN=98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours)
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 53 Summary for Subcatchment P1-P: P1 PERVIOUS Runoff = 0.63 cfs @ 12.10 hrs, Volume= 4,354 cf, Depth= 5.99" Routed to Link 11L : Proposed Disturbed Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description 8,717 74 >75% Grass cover, Good, HSG C 8,717 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.1 100 0.0430 0.17 Sheet Flow, Grass: Dense n= 0.240 P2= 3.47" 0.1 44 0.0470 12.36 15.17 Pipe Channel, Yard Inlet 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 0.2 325 0.0450 31.77 898.40 Pipe Channel, 72" Culvert 72.0" Round Area= 28.3 sf Perim= 18.8' r= 1.50' n= 0.013 10.4 469 Total
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 54 Subcatchment P1-P: P1 PERVIOUS Hydrograph 0.7 Runoff 0.63 cfs 0.65 NOAA 24-hr D 0.6 100-Year-2020 Rainfall=9.18" 0.55 P2=3.47" 0.5 Runoff Area=8,717 sf 0.45 Runoff Volume=4,354 cf 0.4 Flow (cfs) Runoff Depth=5.99" 0.35 Flow Length=469' 0.3 Tc=10.4 min 0.25 CN=74 0.2 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours)
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 55 Summary for Subcatchment P2: P-2 Pervious-w-offsite-Undisturbed Runoff = 2.47 cfs @ 12.21 hrs, Volume= 18,963 cf, Depth= 5.87" Routed to Link P-DP 1 : PROP DP 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description * 2,744 98 Roof-offsite * 1,220 98 Impervious 1,506 71 Meadow, non-grazed, HSG C * 32,065 70 wooded * 1,240 74 >75% Grass offsite 38,775 73 Weighted Average 34,811 89.78% Pervious Area 3,964 10.22% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.3 100 0.0900 0.15 Sheet Flow, sheet flow Woods: Light underbrush n= 0.400 P2= 3.47" 1.8 110 0.0400 1.00 Shallow Concentrated Flow, SC Woodland Kv= 5.0 fps 0.6 115 0.0430 3.34 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 0.1 44 0.0500 12.75 15.65 Pipe Channel, Yard drains 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 0.2 325 0.0440 31.42 888.36 Pipe Channel, Culvert 72.0" Round Area= 28.3 sf Perim= 18.8' r= 1.50' n= 0.013 14.0 694 Total
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 56 Subcatchment P2: P-2 Pervious-w-offsite-Undisturbed Hydrograph Runoff 2.47 cfs NOAA 24-hr D 100-Year-2020 Rainfall=9.18" 2 P2=3.47" Runoff Area=38,775 sf Runoff Volume=18,963 cf Flow (cfs) Runoff Depth=5.87" Flow Length=694' 1 Tc=14.0 min CN=73 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours)
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 57 Summary for Subcatchment P3A-IMP: P3A IMPERVIOUS Runoff = 0.45 cfs @ 12.01 hrs, Volume= 3,010 cf, Depth= 8.94" Routed to Link P-DP 2 : PROP DP 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description * 4,040 98 DRIVE/SIDEWALK 4,040 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 100 0.0500 2.07 Sheet Flow, Pavement Smooth surfaces n= 0.011 P2= 3.47" 1.2 335 0.0500 4.54 Shallow Concentrated Flow, shadow concentrate Paved Kv= 20.3 fps 2.0 435 Total
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 58 Subcatchment P3A-IMP: P3A IMPERVIOUS Hydrograph 0.5 Runoff 0.48 0.45 cfs 0.46 0.44 NOAA 24-hr D 0.42 0.4 100-Year-2020 Rainfall=9.18" 0.38 P2=3.47" 0.36 0.34 Runoff Area=4,040 sf 0.32 0.3 Runoff Volume=3,010 cf Flow (cfs) 0.28 0.26 Runoff Depth=8.94" 0.24 0.22 Flow Length=435' 0.2 Slope=0.0500 '/' 0.18 0.16 Tc=2.0 min 0.14 0.12 CN=98 0.1 0.08 0.06 0.04 0.02 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
0.02 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours)
24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 59 Summary for Subcatchment P3A-P: P3A PERVIOUS Runoff = 0.48 cfs @ 12.04 hrs, Volume= 2,961 cf, Depth= 5.99" Routed to Link P-DP 2 : PROP DP 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description 5,928 74 >75% Grass cover, Good, HSG C 5,928 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 100 0.0600 0.27 Sheet Flow, sheet flow Grass: Short n= 0.150 P2= 3.47" 0.1 29 0.0550 3.78 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 6.2 129 Total
File revisions (1)
- Sep 29, 2026
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