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• <br />Sediment Pond A <br />SEDIMENT VOLUME - SEDIMENT POND A <br />The sediment volume calcultions presented below are based <br />on TECHNICAL NOTES from the Soil Conservation Service, <br />Agronomy Note #50 dated January, 1977. The technical paper <br />explains the use of the Universal Soil Loss Equation. The <br />factors used below are obtained from tables from the technical <br />paper. <br />USING THE UNIVERSAL SOIL LOSS EQUATION <br />A= R K L S C P <br />C~ <br />R = rainfall factor <br />K = soil erodibility factor <br />LS = combined length slope factor 2.7% - 2000' <br />H = 100 L = 3650 S = 100/3650 = 'L .7% <br />C = cropping management factor <br />P = erosion control practice factor <br />A = sediment tons/acre/year <br />THREE YEAR SEDIMENT VOLUME ACRE FEET <br />78.8 Acres 115 #/Cubic Feet <br />TOTAL REQUIRED SEDIMENT POND A CAPACITY -- AF <br />PEAK FLOW CALCULATIONS <br /> <br /> COLLECT COLLECT <br /> POND A DITCH DITCH <br /> SPILLWAY CDA-1 CDA-2 <br />DRAINAGE AREA (ACRES) 78.8 0.94 29.8 <br />CURVE NO. 80.0 80.0 80.0 <br />STORM EVENT _YR., 24 HR. 25 10 10 <br />STORM EVENT in. 2.0 1.6 1.6 <br />RUNOFF in. 0.56 0.34 0.34 <br />WATERSHED RELIEF ft. 100 30 100 <br />Lc 25 ft. 2700 150 1050 <br />Lc 50 ft. 1000 150 350 <br />Lc 75 ft. 1100 200 600 <br />WATERSHED SLOPE % 3.5 9.2 3.9 <br />SLOPE ADJUSTMENT FACTOR 0.95 0.94 0.99 <br />LENGHT OF WATERSHED 3650 300 4600 <br />EQUIVALENT DRAINAGE AREA 118 1.8 173 <br />PEAK FLOW cfs/in Fig D-2 70 4.8 95 <br />ADJUSTED PEAK FLOW 25.1 0.78 5.45 <br />30.00 <br />0.22 <br />0.66 <br />1.00 <br />0.50 <br />2.18 <br />0.21 <br />2.41 <br />9-2 <br />