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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 55.6 <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 0.9 <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*D Z)= <br />9.95 Feet2 <br />WETTED PER IMETER=(W)+2*[((X*D) 2+D2)112] <br />13.80 Feet <br />R=AREA/WETTED PERIMETER <br />0.72 <br />V=(1.49/N)*(R213)*(SI12)= <br />5.65 Ft/Sec <br />Q=AXV= <br />56.1 CFS <br />Q REQUIRED - Peak Discharge <br />55.6 CFS <br />Riprap Sizing - Across top of Embankment <br />D50 = Size of Riprap <br />D50 = ((V X S^.17)17.58))^2 <br />D50 = Diameter in feet <br />V = Velocity <br />S = Slope <br />D50 = 0.15 feet 1.76 <br />inches Use Pit Run Material <br />TR -81 App. B-7 10/13 <br />