2025 12 19 Stormwater Report Rev 1

Time of Concentration Calculations Project #: 24-170 Pre-Development Project: The Estate Post-Development County: Essex Drainage Area: DA-2 Sheet Flow Segment 1 Segment 2 Segment 3 Surface Description (Table 3-1) Grass, Dense Grasses Manning's Roughness Coeff., n (Table 3-1) 0.24 - - Flow Length, L (total ≤ 100 ft) 83 Two-Year 24-Hour Rainfall, P2 (CA) 3.47 3.47 3.47 Two-Year 24-Hour Rainfall, P2 (FP) 4.09 4.09 4.09 Land Slope, s (ft/ft) 0.02 Tt (CA) 11.8 - - 11.8 Tt (FP) 10.9 - - 10.9 Shallow Concentrated Flow Segment 1 Segment 2 Segment 3 Surface Description Flow Length, L Watercourse Slope, s (ft/ft) Average Velocity - - - Tt - - - 0.0 Channel Flow Segment 1 Segment 2 Segment 3 Cross Sectional Flow Area, a Wetted Perimeter, Pw Hydraulic Radius, r - - - Channel Slope, s (ft/ft) Manning's Roughness Description Manning's Roughness - - - Velocity - - - Flow Length Tt - - - 0.0 Current Adjusted (CA) 11.8 Future Projected (FP) 10.9