Laserfiche WebLink
which would not interfere with the loadout operations. The <br />• establishment of an insized pond precludes the use of a principle <br />spillway, as the spillway would be located below the elevation of the <br />ground outside the pond and therefore would not drain. Water will be <br />removed from the sediment ponds by means of infiltration, evaporation <br />and pumping when deemed necessary. When pumping the pond care will be <br />taken to ensure that the intake hose of the pump does not extend below <br />the sediment level of the pond. <br />Hvdroloaic Calculations <br />Drainage area = 8.2 ac = 358,600ft2 <br />Maximum height Drainage = 6422 <br />Minimum height Drainage = 6418 <br />Z = 4 <br />LC 25 579 <br />LC 50 2658 <br />• LC 75 1102 <br />Average Slope = S = .25Z (LC25+LC50+LC75)/DA <br />S = 0.012 = 1.20 <br />Slope Adjustment factor = 1 <br />Hydraulic length = 300ft <br />Curve Number = 72 <br />Nesda soil is hydrologic group A(1) <br />Assume surface condition is similar to dirt road <br />Rainfall Events(2) <br />10 year, 24 hour = 2" <br />25 year, 24 hour = 2.4" <br />Runoff Amount <br />• Q = (P-0.255)2/(P+0.85) Where 5 = (1000/CN)-10 = 1.49 <br />10 year, 24 hour Q = 0.29 inches <br />25 year, 24 hour Q = 0.48 inches <br />-3- <br />