Stormwater Management Report 03302026

24-223 DRAINAGE DESIGN-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 74 Subcatchment E2-P: E2A PERVIOUS Hydrograph 0.11 Runoff 0.105 0.10 cfs 0.1 NOAA 24-hr D 0.095 0.09 10-Year-2050 Rainfall=6.37" 0.085 0.08 P2=4.09" 0.075 0.07 Runoff Area=2,099 sf 0.065 Runoff Volume=612 cf Flow (cfs) 0.06 0.055 Runoff Depth=3.50" 0.05 0.045 Flow Length=129' 0.04 Slope=0.0600 '/' 0.035 0.03 Tc=5.7 min 0.025 0.02 CN=74 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

15 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-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 75 Summary for Subcatchment E2B-IMP: E2B IMPERVIOUS Runoff = 0.09 cfs @ 12.00 hrs, Volume= 614 cf, Depth= 6.13" Routed to Link E-DP 2 : EXIST 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 10-Year-2050 Rainfall=6.37", P2=4.09" Area (sf) CN Description 1,202 98 Paved parking, HSG C 1,202 100.00% 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 0.0250 3.21 Shallow Concentrated Flow, shadow concentrate Paved Kv= 20.3 fps 1.1 188 Total

24-223 DRAINAGE DESIGN-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 E2B-IMP: E2B IMPERVIOUS Hydrograph 0.105 Runoff 0.1 0.09 cfs 0.095 0.09 NOAA 24-hr D 0.085 10-Year-2050 Rainfall=6.37" 0.08 0.075 P2=4.09" 0.07 0.065 Runoff Area=1,202 sf 0.06 Runoff Volume=614 cf Flow (cfs) 0.055 0.05 Runoff Depth=6.13" 0.045 Flow Length=188' 0.04 0.035 Tc=1.1 min 0.03 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

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-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 E2B-P: E2B PERVIOUS Runoff = 0.07 cfs @ 12.05 hrs, Volume= 447 cf, Depth= 3.50" Routed to Link E-DP 2 : EXIST 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 10-Year-2050 Rainfall=6.37", P2=4.09" Area (sf) CN Description 1,532 74 >75% Grass cover, Good, HSG C 1,532 100.00% 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 0.0250 2.55 Shallow Concentrated Flow, Lawn Unpaved Kv= 16.1 fps 5.3 188 Total

24-223 DRAINAGE DESIGN-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 E2B-P: E2B PERVIOUS Hydrograph Runoff 0.08 0.07 cfs 0.075 NOAA 24-hr D 0.07 0.065 10-Year-2050 Rainfall=6.37" 0.06 P2=4.09" 0.055 Runoff Area=1,532 sf 0.05 Runoff Volume=447 cf Flow (cfs) 0.045 0.04 Runoff Depth=3.50" 0.035 Flow Length=188' 0.03 Tc=5.3 min 0.025 0.02 CN=74 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 Time (hours)

24-223 DRAINAGE DESIGN-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 Link 8L: EXISTING DISTURBED Inflow Area = 69,893 sf,100.00% Impervious, Inflow Depth = 6.13" for 10-Year-2050 event Inflow = 5.45 cfs @ 12.01 hrs, Volume= 35,712 cf Primary = 5.45 cfs @ 12.01 hrs, Volume= 35,712 cf, Atten= 0%, Lag= 0.0 min Routed to Link E-DP 1 : EXIST DP 1 Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs Link 8L: EXISTING DISTURBED Hydrograph Inflow 6 5.45 cfs Primary 5.45 cfs Inflow Area=69,893 sf 5 4 Flow (cfs) 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-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 Summary for Link 9L: TOTAL EXISTING Inflow Area = 133,103 sf, 63.90% Impervious, Inflow Depth = 5.07" for 10-Year-2050 event Inflow = 8.26 cfs @ 12.03 hrs, Volume= 56,272 cf Primary = 8.26 cfs @ 12.03 hrs, Volume= 56,272 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs Link 9L: TOTAL EXISTING Hydrograph Inflow 9 8.26 cfs Primary 8.26 cfs Inflow Area=133,103 sf 8 7 6 Flow (cfs) 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)

24-223 DRAINAGE DESIGN-EXISTING-2026-03-30 NOAA 24-hr D 10-Year-2050 Rainfall=6.37", 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 Link E-DP 1: EXIST DP 1 Inflow Area = 116,235 sf, 61.79% Impervious, Inflow Depth = 5.00" for 10-Year-2050 event Inflow = 7.06 cfs @ 12.04 hrs, Volume= 48,450 cf Primary = 7.06 cfs @ 12.04 hrs, Volume= 48,450 cf, Atten= 0%, Lag= 0.0 min Routed to Link 9L : TOTAL EXISTING Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.50 hrs Link E-DP 1: EXIST DP 1 Hydrograph Inflow 7.06 cfs Primary 7 7.06 cfs Inflow Area=116,235 sf 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)