Laserfiche WebLink
COLLECTION DITCH CD-2 <br /> 1.0~ SLOPE AREA <br />• FLOW <br />F FROM DRAINAGE AREA NO. 2 & B <br />LOW IN A TRIANGULAR CHANNEL <br /> <br />DEPTH D 1.750 FEET <br />SIAPE S 0.010 EXPRESS AS DECIMAL <br />MANNINGS "N" N 0.030 EXPRESS AS DECIMAL <br />DITCH SIDE SLOPE X 1.500 SLOPE = X:1 <br />AREA=(W*D)+(X*D)= 4.59 FEET^2 <br />WETTED PERIMETER=(W)+2( (XD^2+D^2))^.5 6.31 FEET <br />R=AREA/WETTED PERMITER 0.73 <br />V=(1.49/N)*(R^.667)*(S^ .5)= 4.02 FEET/SEC <br />Q = A X V = 18.46 CFS <br />Q REQUIRED 17.81 <br />Collection ditch CD-2 will be a V ditch 2.000 feet deep. <br />1.Sh:ly side slopes. With a freeboard of 0.3' the total depth <br />of CD-2 is 2.300 feet. The flow velocity is slow enough <br />erosion should not be a problem. <br />COLLECTION DITCH CD-A <br />FLOW FROM DRAINAGE AREA NO. A <br />FLOW IN A TRIANGU LAR CHANNEL <br />DEPTH D 0.800 FEET <br />SLOPE S 0.010 EXPRESS AS DECIMAL <br />MANNINGS "N" N 0.030 EXPRESS AS DECIMAL <br />DITCH SIDE SLOPE X 1.500 SLOPE = X:1 <br />AREA=(W*D)+(X*D)= 0.96 FEET^2 <br />WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 2.88 FEET <br />R=AREA/WETTED PERMITER 0.33 <br />V=(1.49/N)*(R^.667)*(S^.5)= 2.39 FEET/SEC <br />Q = A X V = 2.29 CFS <br />Q REQUIRED - 1.83 <br />Collection ditch CD-A will be a V ditch 0.800 feet deep. <br />1.5h:1v side slopes. With a freeboard of 0.3' the total depth <br />of CD-A is 1.100 feet. The flow velocity is slow enough <br />erosion should not be a problem. <br />• B-94 <br />