2026 05 Storm Water Management Report rcd 5 6 2026

2 0.15 0.2 Tc=0.6 min 0.18 0.1 0.16 CN=98 0.05 0.14 0.12 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 0.1 Time (hours) 0.08 0.06 0.04 0.02 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

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)

2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" 2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 5/5/2026 Prepared by Dynamic Engineering Printed 5/5/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 35 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment 9S: PDA #1 - Pervious to Bio Summary for Subcatchment 10S: PDA #1 - Impervious (On-Site Conveyance) Runoff = 0.26 cfs @ 12.13 hrs, Volume= 0.018 af, Depth= 3.23" Runoff = 1.15 cfs @ 12.10 hrs, Volume= 0.087 af, Depth= 5.14" Routed to Pond 2P : BIO BASIN Routed to Link 4L : POI #1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs 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" NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Area (ac) CN Description Area (ac) CN Description 0.068 80 >75% Grass cover, Good, HSG D 0.204 98 Paved parking, HSG D 0.068 100.00% Pervious Area

0.204 98 Paved parking, HSG D 0.068 100.00% Pervious Area 0.204 100.00% Impervious Area Tc Length Slope Velocity Capacity Description Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) (min) (feet) (ft/ft) (ft/sec) (cfs) 5.2 45 0.0450 0.14 Sheet Flow, A-B 1.1 93 0.0188 1.38 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" Smooth surfaces n= 0.011 P2= 3.47" 0.2 29 0.0148 2.47 Shallow Concentrated Flow, B-C 1.0 326 0.0115 5.64 6.93 Pipe Channel, B-C Paved Kv= 20.3 fps 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' 0.1 18 0.1180 5.53 Shallow Concentrated Flow, C-D (RIP-RAP) n= 0.013 Corrugated PE, smooth interior Unpaved Kv= 16.1 fps 2.1 419 Total 5.5 92 Total Subcatchment 10S: PDA #1 - Impervious (On-Site Conveyance) Subcatchment 9S: PDA #1 - Pervious to Bio

Subcatchment 9S: PDA #1 - Pervious to Bio Hydrograph Hydrograph Runoff 1.15 cfs Runoff 0.28 0.26 cfs NOAA 24-hr D 0.26 NOAA 24-hr D 10-Year-Current Rainfall=5.38" 1 0.24 10-Year-Current Rainfall=5.38" P2=3.47" 0.22 P2=3.47" Runoff Area=0.204 ac 0.2 Runoff Area=0.068 ac Runoff Volume=0.087 af

noff Area=0.068 ac Runoff Volume=0.087 af Runoff Volume=0.018 af Flow (cfs) 0.18 Runoff Depth=5.14" Flow (cfs) 0.16 Runoff Depth=3.23" Flow Length=419' 0.14 Flow Length=92' Tc=2.1 min 0.12 Tc=5.5 min CN=98 0.1 CN=80 0.08 0.06 0.04 0.02 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 0 Time (hours) 0 2 4 6 8 10 12

Time (hours) 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)

2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" 2026-04 Proposed & Existing ConditNOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Prepared by Dynamic Engineering Printed 5/5/2026 Prepared by Dynamic Engineering Printed 5/5/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 37 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment 11S: PDA #1 - Pervious (On-Site Conveyance) Summary for Subcatchment 12S: PDA #2 - Impervious Runoff = 0.28 cfs @ 12.13 hrs, Volume= 0.019 af, Depth= 3.23" Runoff = 0.10 cfs @ 12.10 hrs, Volume= 0.007 af, Depth= 5.14" Routed to Link 4L : POI #1 Routed to Link 5L : POI #2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs 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" NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Area (ac) CN Description Area (ac) CN Description 0.071 80 >75% Grass cover, Good, HSG D 0.017 98 Paved parking, HSG D 0.071 100.00% Pervious Area

0.017 98 Paved parking, HSG D 0.071 100.00% Pervious Area 0.017 100.00% Impervious Area Tc Length Slope Velocity Capacity Description Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 20 0.0200 0.09 Sheet Flow, A-B 0.5 42 0.0260 1.34 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" Smooth surfaces n= 0.011 P2= 3.47" 0.5 35 0.0200 1.16 Sheet Flow, B-C 0.3 58 0.0300 3.52 Shallow Concentrated Flow, B-C Smooth surfaces n= 0.011 P2= 3.47" Paved Kv= 20.3 fps 1.0 326 0.0115 5.64 6.93 Pipe Channel, C-D 0.8 100 Total 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior Subcatchment 12S: PDA #2 - Impervious 5.3 381 Total Hydrograph Subcatchment 11S: PDA #1 - Pervious (On-Site Conveyance)

Hydrograph Subcatchment 11S: PDA #1 - Pervious (On-Site Conveyance) 0.105 Runoff 0.1 0.10 cfs Hydrograph 0.095 NOAA 24-hr D 0.09 0.3 0.28 cfs Runoff 0.085 10-Year-Current Rainfall=5.38" 0.28 NOAA 24-hr D 0.08 P2=3.47" 0.075 0.26