Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

2026-02 Proposed Conditions - AJH Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 2 Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC P2 Name (hours) (inches) (inches) 1 2-Year-Current NOAA 24-hr D Default 24.00 1 3.47 2 3.47 2 2-Year-Projected NOAA 24-hr D Default 24.00 1 4.09 2 4.09 3 10-Year-Current NOAA 24-hr D Default 24.00 1 5.38 2 3.47 4 10-Year-Projected NOAA 24-hr D Default 24.00 1 6.37 2 4.09 5 100-Year-Current NOAA 24-hr D Default 24.00 1 9.18 2 3.47 6 100-Year-Projected NOAA 24-hr D Default 24.00 1 11.52 2 4.09

2026-02 Proposed Conditions - AJH NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1S: EDA #1 - Impervious Runoff = 1.43 cfs @ 12.10 hrs, Volume= 0.107 af, Depth= 3.24" Routed to Link 1L : POI #1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) CN Description * 0.396 98 Impervious Surfaces 0.396 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0100 1.09 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.47" 0.2 119 0.0400 10.53 12.92 Pipe Channel, B-C 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 1.7 219 Total Subcatchment 1S: EDA #1 - Impervious Hydrograph Runoff 1.43 cfs NOAA 24-hr D 2-Year-Current Rainfall=3.47" P2=3.47" Runoff Area=0.396 ac 1 Runoff Volume=0.107 af Flow (cfs)

1 Runoff Volume=0.107 af Flow (cfs) Runoff Depth=3.24" Flow Length=219' Tc=1.7 min CN=98 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

2026-02 Proposed Conditions - AJH NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 2S: EDA #1 - Pervious Runoff = 0.13 cfs @ 12.13 hrs, Volume= 0.011 af, Depth= 0.56" Routed to Link 1L : POI #1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) CN Description 0.241 61 >75% Grass cover, Good, HSG B 0.241 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.0 34 0.0500 0.14 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" 0.5 124 0.0410 4.11 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.1 13 0.0030 2.69 2.11 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Concrete pipe, finished 0.2 96 0.0144 6.84 8.40 Pipe Channel, D-E 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 Concrete pipe, finished 4.8 267 Total Subcatchment 2S: EDA #1 - Pervious Hydrograph Runoff 0.14 0.13 cfs 0.13 NOAA 24-hr D 0.12 2-Year-Current Rainfall=3.47" 0.11

0.12 2-Year-Current Rainfall=3.47" 0.11 P2=3.47" 0.1 Runoff Area=0.241 ac 0.09 Runoff Volume=0.011 af Flow (cfs) 0.08 Runoff Depth=0.56" 0.07 Flow Length=267' 0.06 Tc=4.8 min 0.05 CN=61 0.04 0.03 0.02 0.01 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

2026-02 Proposed Conditions - AJH NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 5 Summary for Link 1L: POI #1 Inflow Area = 0.637 ac, 62.17% Impervious, Inflow Depth = 2.22" for 2-Year-Current event Inflow = 1.55 cfs @ 12.10 hrs, Volume= 0.118 af Primary = 1.55 cfs @ 12.10 hrs, Volume= 0.118 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Link 1L: POI #1 Hydrograph Inflow 1.55 cfs Primary 1.55 cfs Inflow Area=0.637 ac 1 Flow (cfs) 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

2026-02 Proposed Conditions - AJHNOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1S: EDA #1 - Impervious Runoff = 1.69 cfs @ 12.10 hrs, Volume= 0.127 af, Depth= 3.85" Routed to Link 1L : POI #1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs NOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" Area (ac) CN Description * 0.396 98 Impervious Surfaces 0.396 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.4 100 0.0100 1.18 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 4.09" 0.2 119 0.0400 10.53 12.92 Pipe Channel, B-C 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 1.6 219 Total Subcatchment 1S: EDA #1 - Impervious Hydrograph Runoff 1.69 cfs NOAA 24-hr D 2-Year-Projected Rainfall=4.09" P2=4.09" Runoff Area=0.396 ac Runoff Volume=0.127 af Flow (cfs) 1

0.396 ac Runoff Volume=0.127 af Flow (cfs) 1 Runoff Depth=3.85" Flow Length=219' Tc=1.6 min CN=98 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

2026-02 Proposed Conditions - AJHNOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 2S: EDA #1 - Pervious Runoff = 0.23 cfs @ 12.13 hrs, Volume= 0.017 af, Depth= 0.86" Routed to Link 1L : POI #1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs NOAA 24-hr D 2-Year-Projected Rainfall=4.09", P2=4.09" Area (ac) CN Description 0.241 61 >75% Grass cover, Good, HSG B 0.241 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.7 34 0.0500 0.15 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 4.09" 0.5 124 0.0410 4.11 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.1 13 0.0030 2.69 2.11 Pipe Channel, C-D 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Concrete pipe, finished 0.2 96 0.0144 6.84 8.40 Pipe Channel, D-E 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 Concrete pipe, finished 4.5 267 Total Subcatchment 2S: EDA #1 - Pervious Hydrograph 0.26 Runoff 0.25 0.23 cfs 0.24 0.23 NOAA 24-hr D 0.22 0.21 2-Year-Projected Rainfall=4.09" 0.2 0.19

hr D 0.22 0.21 2-Year-Projected Rainfall=4.09" 0.2 0.19 P2=4.09" 0.18 Runoff Area=0.241 ac 0.17 0.16 Runoff Volume=0.017 af 0.15 Flow (cfs) 0.14 Runoff Depth=0.86" 0.13 0.12 Flow Length=267' 0.11 0.1 Tc=4.5 min 0.09 CN=61 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)