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OPERATIONS CONFIGURATION <br />Subwatershed information for "H" and "I" ditches found in Volume III, Exhbit f <br />Ditch H-1 <br />Ditch H-1 receives flow from Drainage Area F, Pond F dewatering pump, and local run-off <br />Ditch H-1 exists as a trapezoidal channel, so evaluation for trapezoidal channel will remail <br />Drainage Ditch D -H1 14% Slope Reach <br />Manning's Equation <br />Flow In a Trapezoidal Channe <br />DEPTH <br />D <br />0 300 <br />WIDTH <br />W <br />2000 <br />Slope <br />S <br />0140 <br />Mannings "N" <br />N <br />0 040 <br />SIDE SLOPE <br />X <br />2000 <br />AREA=(W D)+(X*D"2)= <br />SIDE SLOPE <br />X <br />WETTED PERIMETER=(W)+2*[((X*D)^2+D^2)^0 5] <br />SLOPE = X 1 <br />R=AREAM/ETTED PERIMETER <br />V=(1.49/N)*(R^ 667)*(S^ 5)= <br />Q=AXV= <br />Q REQUIRED - Peak Discharge <br />Riprap Sizing - Drainage Ditch D -H1 <br />14% Slope React <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 />FEET <br />FEET <br />EXPRESS AS DECIMAL <br />EXPRESS AS DECIMAL <br />SLOPE = X 1 <br />D50 = 0 2 feet 3 inches <br />Drainage Ditch D -H1 1% Slope Reach <br />Manning's Equation <br />Flow In a Trapezoidal Channe <br />078 FEET ^2 <br />334 FEET <br />023 <br />528 FT/SEC <br />412 CFS <br />307 CFS <br />DEPTH <br />D <br />0.500 <br />FEET <br />WIDTH <br />W <br />2.000 <br />FEET <br />Slope <br />S <br />0 010 <br />EXPRESS AS DECIMAL <br />Mannings "N" <br />N <br />0 030 <br />EXPRESS AS DECIMAL <br />SIDE SLOPE <br />X <br />2000 <br />SLOPE = X 1 <br />AREA=(W*D)+(X*DA2)= <br />WETTED PERIMETER=(W)+2*[((X*D)^2+D^2)^0 5] <br />R=AREA/WETTED PERIMETER <br />V=(1 49/N)*(R^.667)*(SA.5)= <br />Q=AXV= <br />Q REQUIRED - Peak Discharge <br />1.50 FEET ^2 <br />4.24 FEET <br />035 <br />2 49 FT/SEC <br />3 73 CFS <br />307 CFS <br />TR -105 Volume XI, App. B-7 09/15 <br />