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 5 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 9S: PDA #1 - Pervious to Bio Summary for Subcatchment 10S: PDA #1 - Impervious (On-Site Conveyance) Runoff = 0.13 cfs @ 12.13 hrs, Volume= 0.009 af, Depth= 1.61" Runoff = 0.74 cfs @ 12.10 hrs, Volume= 0.055 af, Depth= 3.24" 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 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 0.068 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

te Conveyance) Subcatchment 9S: PDA #1 - Pervious to Bio Hydrograph Hydrograph 0.8 Runoff 0.74 cfs Runoff 0.14 0.13 cfs 0.75 NOAA 24-hr D 0.7 0.13 NOAA 24-hr D 2-Year-Current Rainfall=3.47" 0.65 0.12 2-Year-Current Rainfall=3.47" 0.6 P2=3.47" 0.11 P2=3.47" 0.55

.47" 0.11 P2=3.47" 0.55 Runoff Area=0.204 ac 0.1 Runoff Area=0.068 ac 0.5 Runoff Volume=0.055 af Flow (cfs) 0.09 Runoff Volume=0.009 af 0.45 Runoff Depth=3.24" Flow (cfs) 0.08 Runoff Depth=1.61" 0.4 Flow Length=419' 0.35 0.07 Flow Length=92' Tc=2.1 min 0.06 0.3 Tc=5.5 min

Tc=5.5 min CN=98 0.25 0.05 CN=80 0.2 0.04 0.15 0.03 0.1 0.02 0.05 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 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)