Stormwater Management Report 03302026

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 113 Summary for Subcatchment 1S: Roof Runoff = 5.66 cfs @ 12.00 hrs, Volume= 37,633 cf, Depth=11.28" Routed to Link 11L : Proposed Disturbed Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Area (sf) CN Description * 40,040 98 Roof and Amenity Area 40,040 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 53 0.0200 1.37 Sheet Flow, ROOF Smooth surfaces n= 0.011 P2= 4.09" 0.5 196 0.0200 6.95 5.46 Pipe Channel, 12 ROOF DRAIN 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 0.3 217 0.0424 11.74 14.41 Pipe Channel, 15 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 1.4 466 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 114 Subcatchment 1S: Roof Hydrograph Runoff 6 5.66 cfs NOAA 24-hr D 5 100-Year-2050 Rainfall=11.52" P2=4.09" Runoff Area=40,040 sf 4 Runoff Volume=37,633 cf Flow (cfs) Runoff Depth=11.28" 3 Flow Length=466' Tc=1.4 min 2 CN=98 1 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 115 Summary for Subcatchment P1-I: P1 IMPERVIOUS PARKING Runoff = 3.43 cfs @ 12.01 hrs, Volume= 22,835 cf, Depth=11.28" Routed to Link 11L : Proposed Disturbed Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Area (sf) CN Description * 24,295 98 Uncovered Paved parking, HSG C 24,295 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.4 100 0.0150 1.21 Sheet Flow, sheet flow Parking area n= 0.013 P2= 4.09" 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 2.6 425 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 116 Subcatchment P1-I: P1 IMPERVIOUS PARKING Hydrograph Runoff 3.43 cfs NOAA 24-hr D 100-Year-2050 Rainfall=11.52" 3 P2=4.09" Runoff Area=24,295 sf Runoff Volume=22,835 cf Flow (cfs) 2 Runoff Depth=11.28" Flow Length=425' Tc=2.6 min CN=98 1 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 117 Summary for Subcatchment P1-P: P1 PERVIOUS Runoff = 0.59 cfs @ 12.04 hrs, Volume= 3,661 cf, Depth= 8.17" Routed to Link 11L : Proposed Disturbed Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Area (sf) CN Description 5,380 74 >75% Grass cover, Good, HSG C 5,380 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 83 0.0660 0.21 Sheet Flow, Grass: Dense n= 0.240 P2= 4.09" 0.1 36 0.0280 9.54 11.71 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 7.0 444 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 118 Subcatchment P1-P: P1 PERVIOUS Hydrograph 0.65 Runoff 0.59 cfs 0.6 NOAA 24-hr D 0.55 100-Year-2050 Rainfall=11.52" 0.5 P2=4.09" 0.45 Runoff Area=5,380 sf 0.4 Runoff Volume=3,661 cf Flow (cfs) 0.35 Runoff Depth=8.17" 0.3 Flow Length=444' Tc=7.0 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 119 Summary for Subcatchment P2: P2 Pervious-w-offsite-Undisturbed Runoff = 4.08 cfs @ 12.15 hrs, Volume= 30,272 cf, Depth= 7.89" Routed to Link P-DP 1 : PROP DP 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Area (sf) CN Description * 708 98 Roof-offsite * 1,220 98 Impervious-offsite 2,721 71 Meadow, non-grazed, HSG C * 32,255 70 wooded 1,240 74 >75% Grass cover, Good, HSG C * 7,915 72 Woods/grass comb., Good, HSG C 46,059 72 Weighted Average 44,131 95.81% Pervious Area 1,928 4.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.4 100 0.0900 0.16 Sheet Flow, sheet flow Woods: Light underbrush n= 0.400 P2= 4.09" 0.6 123 0.5000 3.54 Shallow Concentrated Flow, SC Woodland Kv= 5.0 fps 1.7 445 0.0470 4.40 Shallow Concentrated Flow, Parking lot Paved Kv= 20.3 fps 12.7 668 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 120 Subcatchment P2: P2 Pervious-w-offsite-Undisturbed Hydrograph Runoff 4.08 cfs 4 NOAA 24-hr D 100-Year-2050 Rainfall=11.52" P2=4.09" 3 Runoff Area=46,059 sf Runoff Volume=30,272 cf Flow (cfs) Runoff Depth=7.89" Flow Length=668' 2 Tc=12.7 min CN=72 1 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 121 Summary for Subcatchment P3A-IMP: P3A IMPERVIOUS Runoff = 0.57 cfs @ 12.01 hrs, Volume= 3,797 cf, Depth=11.28" Routed to Link P-DP 2 : PROP DP 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" 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) 0.7 100 0.0500 2.24 Sheet Flow, Pavement Smooth surfaces n= 0.011 P2= 4.09" 1.2 335 0.0500 4.54 Shallow Concentrated Flow, shadow concentrate Paved Kv= 20.3 fps 1.9 435 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2050 Rainfall=11.52", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 122 Subcatchment P3A-IMP: P3A IMPERVIOUS Hydrograph Runoff 0.6 0.57 cfs 0.55 NOAA 24-hr D 100-Year-2050 Rainfall=11.52" 0.5 P2=4.09" 0.45 Runoff Area=4,040 sf 0.4 Runoff Volume=3,797 cf Flow (cfs) 0.35 Runoff Depth=11.28" 0.3 Flow Length=435' 0.25 Slope=0.0500 '/' Tc=1.9 min 0.2 CN=98 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 Time (hours)