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~a <br />Ditch H-t <br />Ditch H-1 receives flow from Drainage Area F, Pond F dewatering pump, and local runoff. <br />Ditch H-1 exists as a trapezoidal channel, so evaluation far trapezoidal channel will remain, <br />Drainage Ditch D-H1 14°k Slope Reach <br />Mannings Equation <br />Flow In a Trapezoidal Channel <br />DEPTH D 0.300 FEET <br />WIDTH W 2.000 FEET <br />Slope S 0.140 EXPRESS AS DECIMAL <br />Mannings "N" N 0.040 EXPRESS AS DECIMAL <br />SIDE SLOPE X 2.000 SLOPE = X:1 <br />AREA=(W'D)+(X'D^2)= <br />WETTED PERIMETER=(W)+2'[((X'Dr2+D^2)^0.5) <br />R=AREA/WETTED PERIMETER <br />V=(1.49/N)'(R^.667)'(5^.5)= <br />Q=AXV= <br />Q REQUIRED -Peak Discharge <br />Riprap Sizing -Drainage Ditch D-H1 14% Slope Reach <br />D50 =Size of Riprap <br />D50 = ((V X S^.17)/7.56))^2 <br />D50 = Diameter in feet <br />V = VelOCity <br />S =Slope <br />D50 = 0.2 feet <br />3 inches <br />0.78 FEET^2 <br />3.34 FEET <br />0.23 <br />5.28 FT/SEC <br />4.12 CFS <br />3.07 CFS <br />Drainage Ditch D-H1 1°k Slope Reach <br />Mannings Equation <br />Flow In a Trapezoidal Channel <br />DEPTH D 0.500 <br />WIDTH W 2.000 <br />Slope S 0.010 <br />Mannings "N" N 0.030 <br />SIDE SLOPE X 2.000 <br />AREA=(W'D)+(X'D^2)= <br />WETTED PERIMETER=(W)+2"(((X'D)^2+D^2)^0.5] <br />R=AREANVETTED PERIMETER <br />V=(1.49/N)'(R^.667)'(S ^.5 )_ <br />Q=AXV= <br />Q REQUIRED -Peak Discharge <br />R-045 <br />/1 PRDIK~ <br />73/07 <br />Exh-9 - 170 - <br />1.50 FEET^2 <br />4.24 FEET <br />0.35 <br />2.49 FT/SEC <br />3.73 CFS <br />3.07 CFS <br />12/06 <br />FEET <br />FEET <br />EXPRESS AS DECIMAL <br />EXPRESS AS DECIMAL <br />SLOPE = X:1 <br />