Laserfiche WebLink
Solution: From Table 5-3 - Tabular Discharges for Type II Storm <br />Distribution (csm/inch) <br />qp = 658 w/Tt = 0 <br />10 year, 24 - hour Peak Discharge <br />q10 = qp Ad Q10 <br />q10 = 658 x 0.008138 x 0.47 = 2.52 cfs <br />Use the above peak discharge, q10, for the inlet culvert flow. <br />Reservoir Liquid Volume: <br />Sedimentation Reservoir shall contain the total volume from a <br />10 year, 24-hour precipitation event. <br />Dentention time for the runoff shall depend upon the water <br />quality. Once the water quality meets or exceeds the <br />standards as set forth in the mine permit, the reservoir <br />shall be dewatered by pumping, <br />Volume Surface Runoff, Vsr = Q10 x Ad <br />12 in/ft <br />Liquid Volume: <br />Vsr = 0.47 x 5.21 = 0.20 Ac-Ft. <br />12 = 8.888 Gu-Ft. <br />Reservoir Sediment Volume: <br />Use Universal Soil Loss Equation (USLE) with an appropriate <br />Sediment Delivery Ratio. <br />Ys R.K.LS.CP.Dr - (USLE) x (Dr) <br />Ys = Sediment Yield (tons/acre/year) <br />R = Rainfall Factor <br />K = Soil Erodibility Factor <br />LS = Length Slope Factor <br />CP = Control Practice Factor <br />Dr = Sediment Delivery Ratio <br />The sediment yield method and figures used are from "Hydrology <br />and Sedimentology of Surface Mined Lands," by C. 7. Haan and <br />B. J. Barfield, except where indicated. <br />