2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing Conditi NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" 2026-04 Proposed & Existing Conditi NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 7 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 11S: PDA #1 - Pervious (On-Site Conveyance) Summary for Subcatchment 12S: PDA #2 - Impervious Runoff = 0.14 cfs @ 12.13 hrs, Volume= 0.010 af, Depth= 1.61" Runoff = 0.06 cfs @ 12.10 hrs, Volume= 0.005 af, Depth= 3.24" 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 2-Year-Current Rainfall=3.47", P2=3.47" NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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) Runoff 0.065 0.06 cfs Hydrograph 0.06 NOAA 24-hr D 0.15 0.14 cfs Runoff 0.055 2-Year-Current Rainfall=3.47" 0.14 P2=3.47" NOAA 24-hr D 0.05 0.13 Runoff Area=0.017 ac 2-Year-Current Rainfall=3.47" 0.045 0.12

0.12 Runoff Volume=0.005 af P2=3.47" 0.04 Flow (cfs) 0.11 Runoff Depth=3.24" Runoff Area=0.071 ac 0.035 0.1 Flow Length=100' 0.09 Runoff Volume=0.010 af 0.03 Tc=0.8 min Flow (cfs) 0.08 Runoff Depth=1.61" 0.025 CN=98 0.07 Flow Length=381' 0.02 0.06

Flow Length=381' 0.02 0.06 Tc=5.3 min 0.015 0.05 CN=80 0.01 0.04 0.005 0.03 0 0.02 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) 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)