Laserfiche WebLink
Therefore, the total design volume below the emergency spillway is 7.2 + 0.1 +2.6 ac -ft which is <br />9.9 acre -ft. As is shown in the SEDCAD details, the bottom of the emergency spillway is <br />5616.0', which has a volume of 12.3 acre -ft at this elevation. <br />Pond Sediment Volume Calculation based on Universal Soil Loss Equation (SurvCAD) <br />Input Data <br />Landuse Area <br />(ft ^2) <br />Rainfall Erod- Length Slope Ls Cf Pf <br />Factor <br />ability (ft) ( %) <br />0.37 3076.0 4.1 1.61 0.04 1.00 <br />Reclamat 7235316.0 50.0 <br />Runoff = 0.517 inch. <br />Sediment Density = 175.000 <br />Time = 3.0 years <br />Drainage Ratio = 0.84 <br />Total Area = 166.100 acres <br />Gross Erosion = 198.206 tons /yr. <br />Total Yield = 166.493 tons /yr. <br />Runoff Volume = 7.162 acre -ft <br />Sediment Volume = 0.131 acre -ft (3 year total) <br />Total Volume = 7.293 acre -ft <br />The Cf factor is determined from the chart on page 6, shown in Design Hydrology and <br />Sedimentology for Small Catchments by Haan, Barfield and Hayes. Based on an approximate <br />ground cover of 70% for permanent pasture, a Cf factor of 0.04 was used, which is <br />conservative. <br />The pond volume below the primary spillway will be comprised of two design needs: <br />1) 3 year sediment delivery of 0.1 acre -ft, as based on the calculations above. <br />2) Maximum pit pumping of water into pond 011 of 2.6 acre -ft. <br />As seen in the stage storage relationship, the pond has 5.2 acre -ft of storage at this elevation. <br />Detention time of 24 hours is shown in the SEDCAD outputs, which are at the end of this <br />Revised February 2010 (PR06) Attachment 2.05.3(3) -22 -8 <br />