Stormwater Management Report Revised as of 01282026 4936 0314 8685 v2

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 98 Subcatchment P1-P: P1 PERVIOUS Hydrograph 0.42 Runoff 0.4 0.38 cfs 0.38 0.36 NOAA 24-hr D 0.34 10-Year-2050 Rainfall=6.37" 0.32 0.3 P2=4.09" 0.28 Runoff Area=8,717 sf 0.26 0.24 Runoff Volume=2,541 cf Flow (cfs) 0.22 0.2 Runoff Depth=3.50" 0.18 Flow Length=469' 0.16 0.14 Tc=9.6 min 0.12 0.1 CN=74 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 99 Summary for Subcatchment P2: P-2 Pervious-w-offsite-Undisturbed Runoff = 1.45 cfs @ 12.21 hrs, Volume= 10,980 cf, Depth= 3.40" 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 10-Year-2050 Rainfall=6.37", P2=4.09" 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) 10.4 100 0.0900 0.16 Sheet Flow, sheet flow Woods: Light underbrush n= 0.400 P2= 4.09" 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 13.1 694 Total

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 100 Subcatchment P2: P-2 Pervious-w-offsite-Undisturbed Hydrograph Runoff 1.45 cfs NOAA 24-hr D 10-Year-2050 Rainfall=6.37" P2=4.09" Runoff Area=38,775 sf 1 Runoff Volume=10,980 cf Flow (cfs) Runoff Depth=3.40" Flow Length=694' Tc=13.1 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 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 101 Summary for Subcatchment P3A-IMP: P3A IMPERVIOUS Runoff = 0.31 cfs @ 12.01 hrs, Volume= 2,064 cf, Depth= 6.13" 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 10-Year-2050 Rainfall=6.37", 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-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 102 Subcatchment P3A-IMP: P3A IMPERVIOUS Hydrograph 0.34 Runoff 0.31 cfs 0.32 0.3 NOAA 24-hr D 0.28 10-Year-2050 Rainfall=6.37" 0.26 P2=4.09" 0.24 0.22 Runoff Area=4,040 sf 0.2 Runoff Volume=2,064 cf Flow (cfs) 0.18 Runoff Depth=6.13" 0.16 0.14 Flow Length=435' 0.12 Slope=0.0500 '/' 0.1 Tc=1.9 min 0.08 0.06 CN=98 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 103 Summary for Subcatchment P3A-P: P3A PERVIOUS Runoff = 0.28 cfs @ 12.05 hrs, Volume= 1,728 cf, Depth= 3.50" 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 10-Year-2050 Rainfall=6.37", P2=4.09" 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) 5.6 100 0.0600 0.30 Sheet Flow, sheet flow Grass: Short n= 0.150 P2= 4.09" 0.1 29 0.0550 3.78 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 5.7 129 Total

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 104 Subcatchment P3A-P: P3A PERVIOUS Hydrograph Runoff 0.3 0.28 cfs 0.28 NOAA 24-hr D 0.26 10-Year-2050 Rainfall=6.37" 0.24 P2=4.09" 0.22 0.2 Runoff Area=5,928 sf Runoff Volume=1,728 cf Flow (cfs) 0.18 0.16 Runoff Depth=3.50" 0.14 Flow Length=129' 0.12 0.1 Tc=5.7 min 0.08 CN=74 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 105 Summary for Subcatchment P3B-IMP: P3B IMPERVIOUS Runoff = 0.08 cfs @ 12.00 hrs, Volume= 501 cf, Depth= 6.13" 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 10-Year-2050 Rainfall=6.37", P2=4.09" Area (sf) CN Description * 980 98 SIDEWALK AREA 980 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 100 0.0900 2.84 Sheet Flow, sidewalk Smooth surfaces n= 0.011 P2= 4.09" 0.5 88 0.0220 3.01 Shallow Concentrated Flow, shadow concentrate Paved Kv= 20.3 fps 1.1 188 Total

24-223 DRAINAGE DESIGN-PROPOSED-UPDATE NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 106 Subcatchment P3B-IMP: P3B IMPERVIOUS Hydrograph 0.085 Runoff 0.08 0.08 cfs 0.075 NOAA 24-hr D 0.07 10-Year-2050 Rainfall=6.37" 0.065 0.06 P2=4.09" 0.055 Runoff Area=980 sf 0.05 Runoff Volume=501 cf Flow (cfs) 0.045 0.04 Runoff Depth=6.13" 0.035 Flow Length=188' 0.03 Tc=1.1 min 0.025 CN=98 0.02 0.015 0.01 0.005 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 10-Year-2050 Rainfall=6.37", P2=4.09" Prepared by Jarmel Kizel Architects & Engnrs Printed 1/28/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 107 Summary for Subcatchment P3B-P: P3B PERVIOUS Runoff = 0.09 cfs @ 12.05 hrs, Volume= 548 cf, Depth= 3.50" 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 10-Year-2050 Rainfall=6.37", P2=4.09" Area (sf) CN Description 1,881 74 >75% Grass cover, Good, HSG C 1,881 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.7 100 0.0900 0.35 Sheet Flow, sheet flow Grass: Short n= 0.150 P2= 4.09" 0.6 88 0.0230 2.44 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 5.3 188 Total