Stormwater Management Report 03302026

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 58 Subcatchment P3A-P: P3A PERVIOUS Hydrograph Runoff 0.5 0.48 cfs NOAA 24-hr D 0.45 100-Year-2020 Rainfall=9.18" 0.4 P2=3.47" 0.35 Runoff Area=5,928 sf Runoff Volume=2,961 cf Flow (cfs) 0.3 Runoff Depth=5.99" 0.25 Flow Length=129' 0.2 Tc=6.2 min CN=74 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-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 59 Summary for Subcatchment P3B-IMP: P3B IMPERVIOUS Runoff = 0.11 cfs @ 12.00 hrs, Volume= 730 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= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" 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 2.61 Sheet Flow, sidewalk Smooth surfaces n= 0.011 P2= 3.47" 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 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 60 Subcatchment P3B-IMP: P3B IMPERVIOUS Hydrograph 0.12 Runoff 0.115 0.11 cfs 0.11 0.105 NOAA 24-hr D 0.1 100-Year-2020 Rainfall=9.18" 0.095 0.09 P2=3.47" 0.085 0.08 Runoff Area=980 sf 0.075 Runoff Volume=730 cf 0.07 Flow (cfs) 0.065 Runoff Depth=8.94" 0.06 0.055 Flow Length=188' 0.05 0.045 Tc=1.1 min 0.04 CN=98 0.035 0.03 0.025 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

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 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 61 Summary for Subcatchment P3B-P: P3B PERVIOUS Runoff = 0.15 cfs @ 12.04 hrs, Volume= 939 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= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" 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) 5.2 100 0.0900 0.32 Sheet Flow, sheet flow Grass: Short n= 0.150 P2= 3.47" 0.6 88 0.0230 2.44 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 5.8 188 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 62 Subcatchment P3B-P: P3B PERVIOUS Hydrograph 0.17 Runoff 0.16 0.15 cfs 0.15 NOAA 24-hr D 0.14 100-Year-2020 Rainfall=9.18" 0.13 P2=3.47" 0.12 Runoff Area=1,881 sf 0.11 0.1 Runoff Volume=939 cf Flow (cfs) 0.09 Runoff Depth=5.99" 0.08 Flow Length=188' 0.07 Tc=5.8 min 0.06 0.05 CN=74 0.04 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 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 63 Summary for Subcatchment P3C: P3C- Roof Area Runoff = 0.51 cfs @ 12.00 hrs, Volume= 3,352 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= 0.00-30.00 hrs, dt= 0.50 hrs NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description * 4,500 98 Roof and Amenity Area 4,500 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 52 0.0100 0.95 Sheet Flow, ROOF Smooth surfaces n= 0.011 P2= 3.47" 0.2 54 0.0216 5.51 1.92 Pipe Channel, 8 ROOF DRAIN 8.0" Round Area= 0.3 sf Perim= 2.1' r= 0.17' n= 0.012 1.1 106 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 64 Subcatchment P3C: P3C- Roof Area Hydrograph 0.55 Runoff 0.51 cfs 0.5 NOAA 24-hr D 0.45 100-Year-2020 Rainfall=9.18" P2=3.47" 0.4 Runoff Area=4,500 sf 0.35 Runoff Volume=3,352 cf Flow (cfs) 0.3 Runoff Depth=8.94" 0.25 Flow Length=106' Tc=1.1 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)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 65 Summary for Link 11L: Proposed Disturbed Inflow Area = 69,715 sf, 92.28% Impervious, Inflow Depth = 8.71" for 100-Year-2020 event Inflow = 7.66 cfs @ 12.01 hrs, Volume= 50,614 cf Primary = 7.66 cfs @ 12.01 hrs, Volume= 50,614 cf, Atten= 0%, Lag= 0.0 min Routed to Link P-DP 1 : PROP DP 1 Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs Link 11L: Proposed Disturbed Hydrograph Inflow 7.66 cfs Primary 8 7.66 cfs Inflow Area=69,715 sf 7 6 5 Flow (cfs) 4 3 2 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-2020 Rainfall=9.18", P2=3.47" Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 66 Summary for Link 15L: TOTAL PROPOSED Inflow Area = 133,103 sf, 56.94% Impervious, Inflow Depth = 7.54" for 100-Year-2020 event Inflow = 12.13 cfs @ 12.04 hrs, Volume= 83,652 cf Primary = 12.13 cfs @ 12.04 hrs, Volume= 83,652 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs Link 15L: TOTAL PROPOSED Hydrograph Inflow 12.13 cfs Primary 13 12 12.13 cfs Inflow Area=133,103 sf 11 10 9 8 Flow (cfs) 7 6 5 4 3 2 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)