2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CoNOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" 2026-04 Proposed & Existing CoNOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" 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 79 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 80 Summary for Subcatchment 8S: PDA #1 - Impervious to Bio Summary for Subcatchment 9S: PDA #1 - Pervious to Bio Runoff = 0.94 cfs @ 12.10 hrs, Volume= 0.073 af, Depth=11.28" Runoff = 0.70 cfs @ 12.12 hrs, Volume= 0.051 af, Depth= 8.98" Routed to Pond 2P : BIO BASIN 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 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-Projected Rainfall=11.52", P2=4.09" NOAA 24-hr D 100-Year-Projected Rainfall=11.52", P2=4.09" Area (ac) CN Description Area (ac) CN Description 0.078 98 Paved parking, HSG D 0.068 80 >75% Grass cover, Good, HSG D 0.078 100.00% Impervious Area

0.068 80 >75% Grass cover, Good, HSG D 0.078 100.00% Impervious Area 0.068 100.00% 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) 0.4 42 0.0326 1.59 Sheet Flow, A-B 4.8 45 0.0450 0.16 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 4.09" Grass: Dense n= 0.240 P2= 4.09" 0.1 18 0.1180 5.53 Shallow Concentrated Flow, B-C (RIP-RAP) 0.2 29 0.0148 2.47 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps Paved Kv= 20.3 fps 0.5 60 Total 0.1 18 0.1180 5.53 Shallow Concentrated Flow, C-D (RIP-RAP) Unpaved Kv= 16.1 fps Subcatchment 8S: PDA #1 - Impervious to Bio 5.1 92 Total Hydrograph Subcatchment 9S: PDA #1 -

Subcatchment 9S: PDA #1 - Pervious to Bio Runoff Hydrograph 1 0.94 cfs NOAA 24-hr D Runoff 100-Year-Projected Rainfall=11.52" 0.75 0.70 cfs P2=4.09" 0.7 NOAA 24-hr D Runoff Area=0.078 ac 0.65 100-Year-Projected Rainfall=11.52" Runoff Volume=0.073 af 0.6 P2=4.09" Runoff Depth=11.28" 0.55 Runoff Area=0.068 ac Flow (cfs) Flow Length=60' 0.5 Runoff Volume=0.051 af Tc=0.5 min

Runoff Volume=0.051 af Tc=0.5 min 0.45 Runoff Depth=8.98" Flow (cfs) CN=98 0.4 Flow Length=92' Tc=5.1 min 0.35 CN=80 0.3 0.25 0.2

0.2 0.15 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)