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• DITCH "A" <br />MANNING'S EQUATION <br />FLOW IN A TRAPEZOIDAL CHANNEL <br />DEPTH 1.200 FEET 1. 5' W/Fre eboard <br />BOTTOM WIDTH 1.000 FEET <br />SLOPE OF DITCH 0.016 EXPRESS AS DECIMAL <br />MANNINGS "N" 0.030 EXPRESS AS DECIMAL <br />SIDE SLOPE 2.000 SLOPE = X:1 <br />AREA=(W*D)+(X*D)= 4.08 FEET^2 <br />WETTED PERIMETER=(W)+2((XD^ 2+D^2))^.5 6.37 FEET <br />R=AREA/WETTED PERMITER 0.64 <br />V=(1.49/N)*(R^.667j*(S^.5j= 4.67 FT/SEC <br />Q = A X V = 19.05 CFS <br />Q REQUIRED AREAS 1, 2, 3 ,4, 5 & 6 16.11 CFS <br />If culverts were placed in Ditch "A", either a single 36" cuvlert or a <br />combination of a 24" and an 18" culvert would be required as follows: <br />24" Capacity - 12.00 <br />• 18" Capacity - 5.75 <br />Total - 17.75 <br />36" Capacity - 32.5 <br />CULVERT 1 <br />Culvert 1 is a 12" diameter corrugated ADS plastic culvert. Tt is <br />designed to convey the run-off from Area 1 over the edge of the <br />embankment to Culvert 4. The mine bench access road collection ditch <br />is also designed to handle the flow from Area 1. Therefore, the <br />diversion of all of the Area 1 flow to Culvert 1 is not necessary. <br />Culvert Diameter 12" <br />Flow Capacity with no head 2.10 CFS <br />Q REQUIRED AREA 1 1.93 CFS <br />CULVERT 2 <br />Culvert 2 is an 18" diameter culvert designed to convey water across <br />the road to Segment 2 of the access road collection ditch. <br />Culvert Diameter <br />Flow Capacity with no head <br />. Q REQUIRED AREA 1 & 2 <br />18" <br />5.75 CFS <br />4.03 CFS <br />11-5 Rev. 02-15-94 <br />