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Appendix 48 <br />Open Channel That Feeds Long Pond <br />The open channel that conveys flow from the No. 1 and No. 3 mine discharge pipes <br />to the long pond must handle the design flow of 70 gpm. There is little if any flow <br />from site run -off that would flow into the open channel. <br />Manning's Equation <br />Flow In a Triangular Channel <br />Depth D 0.200 Feet <br />Slope S 0.080 Express as a Decimal <br />Manning's "N" N 0.030 Express as a Decimal <br />Side Slope X 1.500 Slope = X:1 <br />Area= (X "D')= 0.06 Feet' <br />Wetted Perimeter= 2'[((X "Df +D2)112] 0.72 Feet <br />R= Area/Wetted Perimeter 0.08 <br />V= (1.49 /N)`(F:e") '(S1/2 )= 2.68 Ft/Sec <br />Q =AXV= 0.16 CFS <br />Q REQUIRED 70 GPM Q Calculated = 72.10 GPM <br />The spillway will be a triangular channel 0.2 feet deep with 1.5h:1v side slopes. With a <br />freeboard of 0.4' the required depth of the spillway is 0.6 feet. The flow velocity is slow <br />enough that erosion will not be a problem. <br />`. * <br />• M3 <br />The calculations and information presented on tl`%fj j�"4 jr#Qared by me May 1, 2013 <br />and the information presented is true and correct to the Ifeft of my knowledge and belief. <br />Permit Renewal P -9 -11 New 05 -01 -13 <br />