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Required Cross -Sectional Areas for Channels <br />Description <br />Channel A <br />Channel A <br />Flows Collected in Channel <br />Basin C -D <br />Basin C -D <br />Length of Channel (ft) <br />100 <br />100 <br />Change in Elevation (ft) <br />1.5 <br />1.5 <br />Slope, S (ft/ft) <br />0.0150 <br />0.0150 <br />Roughness Factor, n (dimension -less) <br />for grass channel 1 <br />0.035 <br />0.035 <br />Design for 10 -year with freeboard, 100 -year should be within freeb <br />Design Storm <br />10 -year <br />100 -year <br />Source of Peak Flow, Q <br />Basin C -D <br />Basin C -D <br />Required Peak Flow (cfs) <br />29.6 <br />98.7 <br />Manning Formula Peak Flow (cfs) <br />30.0 <br />99.1 <br />Side Slope factor, Z (Z:1) <br />3.0 <br />3.0 <br />Cross-sectional Area, A (ft) <br />7.6 <br />17.9 <br />Wetted Perimeter, P (ft) <br />11.6 <br />16.4 <br />Hydraulic Radius, R (ft 2/ft) <br />0.66 <br />1.09 <br />Slope, S (ft/ft) <br />0.015 <br />0.015 <br />Flow Depth, Y (ft) <br />0.88 <br />1.64 <br />Top Width, T (ft), without freeboard <br />11.3 <br />15.8 <br />Bottom Width, W (ft) <br />6 <br />6 <br />Flow Velocity, V (fps) <br />3.9 <br />5.5 <br />Hydraulic Mean Depth, D <br />0.67 <br />1.13 <br />Froude Number, F <br />0.85 <br />0.92 <br />Subcritical/Su ercritical <br />Subcritical <br />SubcriticaI <br />Note: assume 1 foot freeboard <br />Total depth (ft) = 1.88 <br />Top Width, T (ft), with freeboard 17.3 <br />APPROACH CHANNEL SHALL BE TRAPEZOIDAL, BOTTOM WIDTH 6 FEET, <br />SIDE SLOPES 3:1, 2 FEET DEEP. <br />Equations: <br />Slope, S = Change in Elevation / Length of Channel <br />Area, A=ZxY2+YxW <br />Wetted Perimeter, P= 2 x Y x (1 + Z2)05 + W <br />Hydraulic Radius, R = A / P <br />Top Width, T = 2 x Z x Y + W <br />Flow, Q= 0.49 x A x Ro.667 x So 5) / n <br />Flow Velocity, V = Q / A <br />Bottom Width, W = initial assumption <br />Height, Y = trial and error input <br />Hydraulic Mean Depth, D = A / T <br />Froude Number, F = V / (g x D)o.5 <br />where: g = gravity acceleration = 32.2 ft/sec? <br />Page A-11 hydrology--Canyon-Dolomite-RevO-May2015.xlsx Channel -A <br />