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Peak Flow Calculations <br />The following peak flow calculations were compiled with SEDCAD. <br />Details of the run-off calculations are shown on the following pages. <br />25 -YR <br />24 HR <br />Event <br />Pond F Drainage 42.9 <br />Flow calculations for the site ditches and culverts are <br />presented in following sections of this exhibit. <br />Spillway Pond F <br />Pond F Emergency Spillway <br />Manning's Equation <br />Flow In a Trapezoidal Channel <br />DEPTH D 0.7 <br />FEET <br />WIDTH W 10 <br />FEET <br />Slope S 0.02 <br />EXPRESS AS DECIMAL <br />Mannings "N" N 0.03 <br />EXPRESS AS DECIMAL <br />SIDE SLOPE X 2 <br />SLOPE = X:1 <br />AREA=(W*D)+(X*D2)= <br />8.37 Feet2 <br />WETTED PERIMETER=(W)+2*[((X*D)2+D2)11) <br />13.26 Feet <br />R=AREA/WETTED PERIMETER <br />0.63 <br />V=(1.49/N)*(R21)*(Sl/2)= <br />5.17 Ft/Sec <br />Q=AXV= <br />43.2 CFS <br />Q REQUIRED - Peak Discharge <br />42.9 CFS <br />Riprap Sizing - Across top of Embankment <br />D50 = Size of Riprap <br />D50 = ((V X S^.17)/7.58))^2 <br />D50 = Diameter in feet <br />V = Velocity <br />S = Slope <br />D50 = 0.12 feet 1.47 <br />inches None required <br />TR -98 App. B-7 04/15 <br />