Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

2026-02 Proposed Conditions - AJH NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment 7S: PDA #1 - Pervious to Bio Runoff = 0.19 cfs @ 12.13 hrs, Volume= 0.013 af, Depth= 3.23" Routed to Pond 2P : BIO BASIN 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 10-Year-Current Rainfall=5.38", P2=3.47" Area (sf) CN Description 2,178 80 >75% Grass cover, Good, HSG D 2,178 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.2 45 0.0450 0.14 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" 0.2 29 0.0148 2.47 Shallow Concentrated Flow, B-C Paved Kv= 20.3 fps 0.1 18 0.1180 5.53 Shallow Concentrated Flow, C-D (RIP-RAP) Unpaved Kv= 16.1 fps 5.5 92 Total Subcatchment 7S: PDA #1 - Pervious to Bio Hydrograph 0.21 Runoff 0.19 cfs 0.2 0.19 NOAA 24-hr D 0.18 10-Year-Current Rainfall=5.38" 0.17 0.16 P2=3.47" 0.15 Runoff Area=2,178 sf 0.14 0.13

47" 0.15 Runoff Area=2,178 sf 0.14 0.13 Runoff Volume=0.013 af Flow (cfs) 0.12 Runoff Depth=3.23" 0.11 0.1 Flow Length=92' 0.09 Tc=5.5 min 0.08 0.07 CN=80 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)

2026-02 Proposed Conditions - AJH NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 27 Summary for Pond 1P: UG BASIN Inflow Area = 0.142 ac,100.00% Impervious, Inflow Depth = 5.14" for 10-Year-Current event Inflow = 0.80 cfs @ 12.10 hrs, Volume= 0.061 af Outflow = 0.31 cfs @ 12.13 hrs, Volume= 0.061 af, Atten= 62%, Lag= 1.7 min Primary = 0.31 cfs @ 12.13 hrs, Volume= 0.061 af Routed to Link 2L : POI #1 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 619.58' @ 12.13 hrs Surf.Area= 0.006 ac Storage= 0.009 af Plug-Flow detention time= 9.0 min calculated for 0.061 af (100% of inflow) Center-of-Mass det. time= 9.0 min ( 752.4 - 743.4 ) Volume Invert Avail.Storage Storage Description #1 617.75' 0.020 af 48.0" Round Pipe Storage L= 70.0' Device Routing Invert Outlet Devices #1 Primary 617.75' 15.0" Round RCP_Round 15" L= 15.0' RCP, rounded edge headwall, Ke= 0.100 Inlet / Outlet Invert= 617.75' / 617.55' S= 0.0133 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 1.23 sf #2 Device 1 617.75' 3.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #3 Device 1 620.25' 6.0" Vert. Orifice C= 0.600 Limited to weir flow at low heads #4 Device 1 621.45' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.31 cfs @ 12.13 hrs HW=619.58' (Free Discharge) 1=RCP_Round 15" (Passes 0.31 cfs of 7.36 cfs potential flow) 2=Orifice (Orifice Controls 0.31 cfs @ 6.29 fps) 3=Orifice ( Controls 0.00 cfs) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs)

2026-02 Proposed Conditions - AJH NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 28 Pond 1P: UG BASIN Hydrograph Inflow 0.9 0.80 cfs Primary 0.85 0.8 Inflow Area=0.142 ac 0.75 0.7 Peak Elev=619.58' 0.65 Storage=0.009 af 0.6 0.55 Flow (cfs) 0.5 0.45 0.4 0.35 0.31 cfs 0.3 0.25 0.2 0.15 0.1 0.05 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 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 29 Summary for Pond 2P: BIO BASIN Inflow Area = 0.140 ac, 64.29% Impervious, Inflow Depth = 4.46" for 10-Year-Current event Inflow = 0.69 cfs @ 12.10 hrs, Volume= 0.052 af Outflow = 0.48 cfs @ 12.11 hrs, Volume= 0.043 af, Atten= 30%, Lag= 0.5 min Primary = 0.48 cfs @ 12.11 hrs, Volume= 0.043 af Routed to Link 2L : POI #1 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 623.29' @ 12.11 hrs Surf.Area= 689 sf Storage= 636 cf Plug-Flow detention time= 150.3 min calculated for 0.043 af (84% of inflow) Center-of-Mass det. time= 74.8 min ( 839.5 - 764.7 ) Volume Invert Avail.Storage Storage Description #1 622.00' 1,219 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 622.00 323 0 0 623.00 577 450 450 624.00 960 769 1,219 Device Routing Invert Outlet Devices #1 Primary 619.11' 15.0" Round Culvert L= 35.0' RCP, rounded edge headwall, Ke= 0.100 Inlet / Outlet Invert= 619.11' / 618.93' S= 0.0051 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 622.86' 0.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 623.70' 48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.48 cfs @ 12.11 hrs HW=623.29' (Free Discharge) 1=Culvert (Passes 0.48 cfs of 12.55 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.48 cfs @ 2.15 fps) 3=Grate ( Controls 0.00 cfs)

2026-02 Proposed Conditions - AJH NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 30 Pond 2P: BIO BASIN Hydrograph Inflow 0.69 cfs Primary 0.75 0.7 Inflow Area=0.140 ac 0.65 0.6 Peak Elev=623.29' 0.55 0.48 cfs Storage=636 cf 0.5 0.45 Flow (cfs) 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 31 Summary for Link 2L: POI #1 Inflow Area = 0.637 ac, 68.48% Impervious, Inflow Depth = 4.38" for 10-Year-Current event Inflow = 2.49 cfs @ 12.11 hrs, Volume= 0.232 af Primary = 2.49 cfs @ 12.11 hrs, Volume= 0.232 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Link 2L: POI #1 Hydrograph Inflow 2.49 cfs Primary 2.49 cfs Inflow Area=0.637 ac 2 Flow (cfs) 1 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 - AJ NOAA 24-hr D 10-Year-Projected Rainfall=6.37", P2=4.09" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 3S: Proposed Roof Runoff = 0.95 cfs @ 12.10 hrs, Volume= 0.073 af, Depth= 6.13" Routed to Pond 1P : UG BASIN 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 10-Year-Projected Rainfall=6.37", P2=4.09" Area (sf) CN Description 6,205 98 Roofs, HSG B 6,205 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 3S: Proposed Roof Hydrograph Runoff 1 0.95 cfs NOAA 24-hr D 10-Year-Projected Rainfall=6.37" P2=4.09" Runoff Area=6,205 sf Runoff Volume=0.073 af Runoff Depth=6.13" Flow (cfs) Tc=1.0 min CN=98

Tc=1.0 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 - AJ NOAA 24-hr D 10-Year-Projected Rainfall=6.37", P2=4.09" Prepared by Dynamic Engineering Printed 2/16/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 4S: PDA #1 - Undetained Impervious Runoff = 1.36 cfs @ 12.10 hrs, Volume= 0.104 af, Depth= 6.13" Routed to Link 2L : 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 10-Year-Projected Rainfall=6.37", P2=4.09" Area (sf) CN Description 8,866 98 Paved parking, HSG D 8,866 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 93 0.0188 1.50 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 4.09" 1.0 326 0.0115 5.64 6.93 Pipe Channel, B-C 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 2.0 419 Total Subcatchment 4S: PDA #1 - Undetained Impervious Hydrograph Runoff 1.36 cfs NOAA 24-hr D 10-Year-Projected Rainfall=6.37" P2=4.09" Runoff Area=8,866 sf 1 Runoff Volume=0.104 af