Stormwater Management Report 03302026

P1-I P1-P P1 PERVIOUS P1 IMPERVIOUS PARKING P3A-P P2 1S P3A PERVIOUS P2 Roof Pervious-w-offsite-Undisturbed 11L P3A-IMP Proposed Disturbed P3A IMPERVIOUS P3B-IMP P-DP 2 P-DP 1 PROP DP 2 P3B IMPERVIOUS PROP DP 1 P3B-P P3B PERVIOUS 15L P3C P3C- Roof Area TOTAL PROPOSED Routing Diagram for 24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 Subcat Reach Pond Link Prepared by Jarmel Kizel Architects & Engnrs, Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 Prepared by Jarmel Kizel Architects & Engnrs Printed 3/30/2026 HydroCAD® 10.20-6a s/n 12607 © 2024 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 14,429 74 >75% Grass cover, Good, HSG C (P1-P, P2, P3A-P, P3B-P) 4,040 98 DRIVE/SIDEWALK (P3A-IMP) 1,220 98 Impervious-offsite (P2) 2,721 71 Meadow, non-grazed, HSG C (P2) 44,540 98 Roof and Amenity Area (1S, P3C) 708 98 Roof-offsite (P2) 980 98 SIDEWALK AREA (P3B-IMP) 24,295 98 Uncovered Paved parking, HSG C (P1-I) 7,915 72 Woods/grass comb., Good, HSG C (P2) 32,255 70 wooded (P2)

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 3 Summary for Subcatchment 1S: Roof Runoff = 1.69 cfs @ 12.01 hrs, Volume= 10,799 cf, Depth= 3.24" 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 2-Year-2020 Rainfall=3.47", P2=3.47" 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) 0.7 53 0.0200 1.26 Sheet Flow, ROOF Smooth surfaces n= 0.011 P2= 3.47" 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 1.5 466 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 4 Subcatchment 1S: Roof Hydrograph Runoff 1.69 cfs NOAA 24-hr D 2-Year-2020 Rainfall=3.47" P2=3.47" Runoff Area=40,040 sf Runoff Volume=10,799 cf Flow (cfs) 1 Runoff Depth=3.24" Flow Length=466' Tc=1.5 min CN=98 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-2020 Rainfall=3.47", 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 5 Summary for Subcatchment P1-I: P1 IMPERVIOUS PARKING Runoff = 1.02 cfs @ 12.01 hrs, Volume= 6,553 cf, Depth= 3.24" 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 2-Year-2020 Rainfall=3.47", P2=3.47" 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) 1.5 100 0.0150 1.12 Sheet Flow, sheet flow Parking area n= 0.013 P2= 3.47" 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 2.7 425 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 6 Subcatchment P1-I: P1 IMPERVIOUS PARKING Hydrograph Runoff 1.02 cfs 1 NOAA 24-hr D 2-Year-2020 Rainfall=3.47" P2=3.47" Runoff Area=24,295 sf Runoff Volume=6,553 cf Flow (cfs) Runoff Depth=3.24" Flow Length=425' Tc=2.7 min CN=98 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-2020 Rainfall=3.47", 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 7 Summary for Subcatchment P1-P: P1 PERVIOUS Runoff = 0.08 cfs @ 12.10 hrs, Volume= 547 cf, Depth= 1.22" 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 2-Year-2020 Rainfall=3.47", P2=3.47" 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) 7.3 83 0.0660 0.19 Sheet Flow, Grass: Dense n= 0.240 P2= 3.47" 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 7.6 444 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 8 Subcatchment P1-P: P1 PERVIOUS Hydrograph Runoff 0.085 0.08 cfs 0.08 NOAA 24-hr D 0.075 0.07 2-Year-2020 Rainfall=3.47" 0.065 P2=3.47" 0.06 0.055 Runoff Area=5,380 sf Runoff Volume=547 cf Flow (cfs) 0.05 0.045 0.04 Runoff Depth=1.22" 0.035 Flow Length=444' 0.03 Tc=7.6 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-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 9 Summary for Subcatchment P2: P2 Pervious-w-offsite-Undisturbed Runoff = 0.53 cfs @ 12.36 hrs, Volume= 4,227 cf, Depth= 1.10" 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 2-Year-2020 Rainfall=3.47", P2=3.47" 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) 11.3 100 0.0900 0.15 Sheet Flow, sheet flow Woods: Light underbrush n= 0.400 P2= 3.47" 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 13.6 668 Total

24-223 DRAINAGE DESIGN-PROPOSED-2026-03-30 NOAA 24-hr D 2-Year-2020 Rainfall=3.47", 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 10 Subcatchment P2: P2 Pervious-w-offsite-Undisturbed Hydrograph Runoff 0.55 0.53 cfs 0.5 NOAA 24-hr D 0.45 2-Year-2020 Rainfall=3.47" P2=3.47" 0.4 Runoff Area=46,059 sf 0.35 Runoff Volume=4,227 cf Flow (cfs) 0.3 Runoff Depth=1.10" 0.25 Flow Length=668' 0.2 Tc=13.6 min 0.15 CN=72 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)