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i • • <br />b_ <br />N <br />M <br />S <br />N <br />Coverfill Pile -Upland Diversion Ditch <br />NOTES: <br />Stations are measured in feet and begin at the inlet or upper end of the ddch. Ditch is 425 feet long. <br />V DRch with 1.5H:1V Side Slopes <br />Design Flow = 10 Year Flow From Basin A4b + A6 = 6.26 + 13.74 = 20 CFS <br />Reference Volume IV -Coal Mine Waste Bank -Appendix BHydrology/Sedimentology Output <br />N =Mannings N <br />Mannings Equation V=1.49M(S^.5)(R"0.667) <br />A =Area Triangular Channel 1.5V:1H Slopes = 1.SD^2 <br />WP =Wetted Perimeter = 2(D"2+1.SD^2)^.5 <br />R = Hydraulic Radius = AreaNVetted Perimeter <br />Shear (psf) =weight of water' Velocity' Depth <br />Minimum ditch depth = 1.6 + 0.3 Freeboard = 1.9' <br />PEC-MAT is suitable for velocities of 20 fps and shear stresses of 6 psf. <br />Flow Data 12 24"ADS Pipe <br />From Computer program Flowmaster Open Channel Flow Module, Version 3.43 <br />Diameter 24 inches <br />Slope 0.3 ft/ft <br />N 0.02 <br />Discharge 20 cfs <br />~~ Depth 0.68 + 0.3 Freeboard = 1.0 feet <br />Velocity 21.27 fps <br />Construct 24-inch D50 size RipRap Stilling Basin at end of 12 - 24-inch pipe <br />As-Built Calculated Data <br />Station Slope DesignFlow N Depth Area WP R Velocity Calc. Flow Shear Erosion <br />