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<br />The following calculations show that the diveraioa ditch at the <br />N~1 refuse facility will safely pans the 100 year-24 hour event. <br />In the summer of 1986, the upper portion of the diversion ditch <br />(from station 18+00 to station 35+00) wan reclaimed. Thin <br />resulted in a greater area flowing to the sediment pond and less <br />area into the remaining portions of the diveraioa ditch. These <br />changes are shown on the sketch of the drainage area enclosed in <br />this section. <br />The new drainage area for the diveraioa ditch is 150.3 acres with <br />an average CN of 77, since the refuse area is well vegetated and <br />the majority of the total acreage wan never disturbed. Bee <br />revised Exhibit C°7 for delineation of this area. <br />• The 100 year - 24 hour precipitation is 2.77 inches. <br />Q = 1.49 (1.571)~l (.0075)ul t3 <br />---- x x x 33 <br />.025 <br />Q = 230 cfa with .5 feet of freeboard since the actual flow depth <br />is only 3.0 feet. Therefore the ditch is adequate to carry the <br />100 pear-24 hour peak flow. <br />The peak flow determination for the 100 pr - 24 hour storm is <br />shown on the following page. <br /> <br />Y~~~ 7 <br />