Stormwater Management Report 03302026

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2050 Rainfall=4.09", 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 76 Subcatchment P2: P2 Pervious-w-offsite-Undisturbed Hydrograph 0.8 Runoff 0.75 0.72 cfs 0.7 NOAA 24-hr D 0.65 2-Year-2050 Rainfall=4.09" 0.6 P2=4.09" 0.55 0.5 Runoff Area=46,059 sf Runoff Volume=5,848 cf Flow (cfs) 0.45 0.4 Runoff Depth=1.52" 0.35 0.3 Flow Length=668' 0.25 Tc=12.7 min 0.2 CN=72 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 2-Year-2050 Rainfall=4.09", 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 77 Summary for Subcatchment P3A-IMP: P3A IMPERVIOUS Runoff = 0.20 cfs @ 12.01 hrs, Volume= 1,298 cf, Depth= 3.85" 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 2-Year-2050 Rainfall=4.09", 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 2-Year-2050 Rainfall=4.09", 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 78 Subcatchment P3A-IMP: P3A IMPERVIOUS Hydrograph 0.22 Runoff 0.21 0.20 cfs 0.2 NOAA 24-hr D 0.19 0.18 2-Year-2050 Rainfall=4.09" 0.17 0.16 P2=4.09" 0.15 0.14 Runoff Area=4,040 sf 0.13 Runoff Volume=1,298 cf Flow (cfs) 0.12 0.11 Runoff Depth=3.85" 0.1 0.09 Flow Length=435' 0.08 Slope=0.0500 '/' 0.07 0.06 Tc=1.9 min 0.05 0.04 CN=98 0.03 0.02 0.01 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

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 2-Year-2050 Rainfall=4.09", 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 79 Summary for Subcatchment P3A-P: P3A PERVIOUS Runoff = 0.13 cfs @ 12.07 hrs, Volume= 821 cf, Depth= 1.66" 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 2-Year-2050 Rainfall=4.09", 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-2026-03-30 NOAA 24-hr D 2-Year-2050 Rainfall=4.09", 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 80 Subcatchment P3A-P: P3A PERVIOUS Hydrograph Runoff 0.14 0.13 cfs 0.13 NOAA 24-hr D 0.12 2-Year-2050 Rainfall=4.09" 0.11 0.1 P2=4.09" 0.09 Runoff Area=5,928 sf Runoff Volume=821 cf Flow (cfs) 0.08 0.07 Runoff Depth=1.66" 0.06 Flow Length=129' 0.05 Tc=5.7 min 0.04 CN=74 0.03 0.02 0.01 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 2-Year-2050 Rainfall=4.09", 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 81 Summary for Subcatchment P3B-IMP: P3B IMPERVIOUS Runoff = 0.05 cfs @ 12.00 hrs, Volume= 315 cf, Depth= 3.85" 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 2-Year-2050 Rainfall=4.09", 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-2026-03-30 NOAA 24-hr D 2-Year-2050 Rainfall=4.09", 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 82 Subcatchment P3B-IMP: P3B IMPERVIOUS Hydrograph Runoff 0.05 cfs 0.05 NOAA 24-hr D 0.045 2-Year-2050 Rainfall=4.09" 0.04 P2=4.09" 0.035 Runoff Area=980 sf Runoff Volume=315 cf Flow (cfs) 0.03 0.025 Runoff Depth=3.85" 0.02 Flow Length=188' Tc=1.1 min 0.015 CN=98 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 Time (hours)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2050 Rainfall=4.09", 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 83 Summary for Subcatchment P3B-P: P3B PERVIOUS Runoff = 0.04 cfs @ 12.06 hrs, Volume= 261 cf, Depth= 1.66" 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 2-Year-2050 Rainfall=4.09", 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

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2050 Rainfall=4.09", 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 84 Subcatchment P3B-P: P3B PERVIOUS Hydrograph 0.046 Runoff 0.044 0.04 cfs 0.042 0.04 NOAA 24-hr D 0.038 0.036 2-Year-2050 Rainfall=4.09" 0.034 0.032 P2=4.09" 0.03 Runoff Area=1,881 sf 0.028 Runoff Volume=261 cf Flow (cfs) 0.026 0.024 0.022 Runoff Depth=1.66" 0.02 0.018 Flow Length=188' 0.016 0.014 Tc=5.3 min 0.012 0.01 CN=74 0.008 0.006 0.004 0.002 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