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<br />• <br />• <br />Sediment Pond D <br />PEAK FLOW CALCULATIONS <br />POND D <br />SPILLWAY <br />DRAINAGE AREA (ACRES) <br />CURVE NO. <br />STORM EVENT YR., 24 HR. <br />STORM EVENT in. <br />RUNOFF in. <br />WATERSHED RELIEF ft. <br />Lc 25 ft. <br />Lc 50 ft. <br />Lc 75 ft. <br />WATERSHED SLOPE <br />SLOPE ADJUSTMENT FACTOR <br />LENGHT OF WATERSHED <br />EQUIVALENT DRAINAGE AREA <br />PEAK FLOW cfs/in Fig D-2 <br />ADJUSTED PEAK FLOW <br />34.8 <br />80.00 <br />25 <br />2.0 <br />0.56 <br />60 <br />900 <br />1350 <br />1150 <br />3.4 <br />0.95 MODERATE <br />2250 <br />52.5 <br />42 <br />14.9 <br />COLLECT <br />DITCH <br />CDD-1 <br />22.3 <br />80.00 <br />10 <br />1.6 <br />0.34 <br />60 <br />300 <br />900 <br />1150 <br />3.6 <br />0.97 MODERATE <br />2250 <br />52.5 <br />42 <br />5.8 <br />POND D EMERGENCY SPILLWAY <br />MANNING'S EQUATION <br />FLOW IN A TRAPEZOIDAL CHANNEL <br />ENTER DEPTH D 0.620 FEET <br />ENTER WIDTH W 6.000 FEET <br />ENTER SLOPE S 0.020 EXPRESS AS DECIMAL <br />ENTER "N" N 0.040 EXPRESS AS DECIMAL <br />ENTER SIDE SLOPE X 2.000 SLOPE = X:1 <br />AREA=(W*D)+(X*D"2)= 4.49 FEET"2 <br />WETTED PERIMETER=(W)+2((XD"2+D"2))".5 8.77 FEET <br />R=AREA/WETTED PERMITER 0.51 <br />V=(1.49/N)*(R".667)*(S".5)= 3.37 FT/SEC <br />Q = A X V = 15.13 CFS <br />Q REQUIRED <br />14.88 CFS <br />9-14 <br />