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Diversion Ditches <br />• <br /> Area Curve Number Area Curve Number <br /> 3A 66 6 74 <br /> 3B 66 7 74 <br /> 4 66 8 74 <br /> 5A 74 9 74 <br /> 5B 74 10 74 <br /> The following peak flow valu es have been calculated using <br /> the computer program Storm. The data sheets which document <br /> the calculations follow this section. <br /> Ditch Slope ~ Peak Flow- CFS <br /> D-7 4.0 9.24 <br /> D-11 2 3.43 <br /> 18" CMP C-2 (Pond P-1) 3.43 <br /> D-2A 5 5.82 <br /> D-2B 2 4.47 <br /> D-2B Design Flow 10.29 <br /> D-6 5.0 9.82 <br /> D-2B Design Flow 2 10.29 <br />• 48" CMP C-6 (Pond 4) 20.11 <br /> UPPER DIVERSI ON DITCH D-7 <br /> FLOW IN A TRIAN GULAR CHANNEL <br /> DEPTH D 1.100 FEET <br /> SLOPE S 0.040 EXPRESS AS DECIMAL <br /> Mannings "N" N 0.030 EXPRESS AS DECIMAL <br /> SIDE SLOPE X 1.500 SLOPE = X:1 <br /> AREA=(W*D)+(X*D^2)= 1.82 FEET^2 <br /> WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 3.97 FEET <br /> R=AREA/WETTED PERMITER 0.46 <br /> V=(1.49/N)*(R^.667)*(S^.5)= 5.90 FEET/SEC <br /> Q = A X V = 10.71 CFS <br /> Q REQUIRED 9.24 <br /> The diversion ditch will be a triangular channel 1.1 <br /> feet deep with 1.5h:1v side slopes. With a freeboard of 0.3' <br /> the total depth of the upper diversion ditch is 1.4 feet. <br /> The flow velocity is high en ough that energy dissipaters <br />• will be required. <br />4-B:6 October 1994 <br />