2026 05 Storm Water Management Report rcd 5 6 2026

Runoff Area=0.068 ac Runoff Volume=0.152 af Runoff Volume=0.038 af Runoff Depth=8.94" Flow (cfs) 0.35 Runoff Depth=6.74" Flow (cfs) Flow Length=419' 0.3 Flow Length=92' 1 Tc=2.1 min 0.25 Tc=5.5 min CN=98 CN=80 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 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 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 CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" 2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", 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 67 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 68 Summary for Subcatchment 11S: PDA #1 - Pervious (On-Site Conveyance) Summary for Subcatchment 12S: PDA #2 - Impervious Runoff = 0.56 cfs @ 12.12 hrs, Volume= 0.040 af, Depth= 6.74" Runoff = 0.16 cfs @ 12.10 hrs, Volume= 0.013 af, Depth= 8.94" 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 100-Year-Current Rainfall=9.18", P2=3.47" NOAA 24-hr D 100-Year-Current Rainfall=9.18", 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) 0.18 Runoff 0.16 cfs Hydrograph 0.17 0.16 NOAA 24-hr D Runoff 0.15 100-Year-Current Rainfall=9.18" 0.6 0.56 cfs 0.14 P2=3.47" 0.55 NOAA 24-hr D 0.13 Runoff Area=0.017 ac 0.5 100-Year-Current Rainfall=9.18" 0.12 Runoff

Runoff Volume=0.013 af P2=3.47" 0.11 Runoff Depth=8.94" Flow (cfs) 0.45 0.1 Runoff Area=0.071 ac 0.4 0.09 Flow Length=100' Runoff Volume=0.040 af 0.08 Tc=0.8 min Runoff Depth=6.74" Flow (cfs) 0.35 0.07 CN=98 0.3 Flow Length=381' 0.06

Flow Length=381' 0.06 Tc=5.3 min 0.05 0.25 CN=80 0.04 0.2 0.03 0.02 0.15 0.01 0.1 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 0.05 Time (hours) 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)

2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" 2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", 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 69 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 70 Summary for Subcatchment 13S: PDA #2 - Pervious Summary for Subcatchment 14S: PDA #3 - Pervious Runoff = 0.21 cfs @ 12.11 hrs, Volume= 0.014 af, Depth= 6.74" Runoff = 0.52 cfs @ 12.16 hrs, Volume= 0.043 af, Depth= 6.74" Routed to Link 5L : POI #2 Routed to Link 6L : POI #3 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 100-Year-Current Rainfall=9.18", P2=3.47" NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Area (ac) CN Description Area (ac) CN Description 0.025 80 >75% Grass cover, Good, HSG D 0.076 80 >75% Grass cover, Good, HSG D 0.025 100.00% Pervious Area

0.076 80 >75% Grass cover, Good, HSG D 0.025 100.00% Pervious Area 0.076 100.00% Pervious 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) 1.8 8 0.0200 0.07 Sheet Flow, A-B 8.9 83 0.0400 0.15 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.47" Grass: Dense n= 0.240 P2= 3.47" 0.1 6 0.0150 0.73 Sheet Flow, B-C Using McCuen-Spiess flow length Smooth surfaces n= 0.011 P2= 3.47" 0.3 62 0.0540 3.49 Shallow Concentrated Flow, 1.2 5 0.0200 0.07 Sheet Flow, C-D Grassed Waterway Kv= 15.0 fps Grass: Dense n= 0.240 P2= 3.47" 9.2 145 Total 0.6 133 0.0290 3.46 Shallow Concentrated Flow, D-E Paved Kv= 20.3 fps Subcatchment 14S: PDA #3 - Pervious 3.7 152 Total

Subcatchment 14S: PDA #3 - Pervious 3.7 152 Total Hydrograph Subcatchment 13S: PDA #2 - Pervious Runoff 0.55 0.52 cfs Hydrograph 0.5 NOAA 24-hr D 0.22 0.21 cfs Runoff 100-Year-Current Rainfall=9.18" 0.45 0.21 P2=3.47" 0.2 NOAA 24-hr D 0.4 Runoff Area=0.076 ac 0.19