Stormwater Report 1

Time of Concentration Calculations Project #: 24-170 Project: The Estate County: Essex Pre-Development Post-Development Drainage Area: DA-1 (Current Adjusted) Sheet Flow Segment 1 Segment 2 Segment 3 Surface Description (Table 3-1) Grass, Dense Grasses Grass, Dense Grasses Manning's Roughness Coeff., n (Table 3-1) 0.24 0.24 20 80 Flow Length, L (total ≤ 100 ft) Two-Year 24-Hour Rainfall, P2 3.47 3.47 0.025 0.05 Land Slope, s (ft/ft) 3.46 7.95 Tt 3.47 - 11.40 Segment 2 paved 340 0.05 4.6 1.25 Segment 3 paved 120 0.025 3.2 0.62 2.20 Segment 1 Segment 2 Segment 3 - - - - - - - - - Shallow Concentrated Flow Surface Description Flow Length, L Watercourse Slope, s (ft/ft) Average Velocity Tt Segment 1 Unpaved 70 0.05 3.6 0.33 Channel Flow Cross Sectional Flow Area, a Wetted Perimeter, Pw Hydraulic Radius, r Channel Slope, s Manning's Roughness Description Manning's Roughness Velocity Flow Length Tt 0.00 13.60