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<br />I <br /> <br />I <br /> <br />It is recognized that a 75 percent farm efficiency is high. However, the <br /> <br /> <br />inclusion of an irrigation management system as part of the project makes <br /> <br /> <br />this a realistic and obtainable value. <br /> <br />I <br /> <br />I <br /> <br />System Losses.--For the computation of an annual diversion, it 'was assumed <br /> <br /> <br />that 30 percent of the annual diversion would be system losses. This value <br /> <br /> <br />would be due largely to operational waste but would include canal seepage <br /> <br /> <br />and evaporation. Evaporation losses were assumed to be 0.4 inches per day <br /> <br />from the water surface. Seepage losses for unlined canal were computed at <br /> <br />0.3 ft3 per day per square foot of wetted area (.1 for lined canal). At <br /> <br /> <br />times of peak flow, this amounts to about 6 percent of the canal capacity. <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />Annual Diversion Rate.--The annual diversion rate is the amount of water <br /> <br /> <br />that must be supplied to the canal to meet the CIR and the losses. This <br /> <br /> <br />value was calculated to be 1.98 acre-feet per acre. The derivation of this <br /> <br /> <br />value is shown on Table 5. <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />Peak Rate.--The peak rate is the rate at which water must be applied to a <br /> <br /> <br />crop during a critical period to prevent stressing the plant. This rate <br /> <br />was calculated for Lake Andes-Wagner Unit using the Jensen-Haise method <br /> <br />with the climatic data and cropping pattern used for computing the CIR, <br /> <br /> <br />along with the estimated available soil moisture. Moisture holding capa- <br /> <br /> <br />city of the soils was estimated at 0.20 inch per inch for soils having a <br /> <br /> <br />low farm water requirement. Soils with an estimated moisture holding capa- <br /> <br /> <br />city of 0.16 inch per inch have a moderate farm water requirement. It was <br /> <br /> <br />further assumed that one-half of the soil moisture is available to the <br /> <br /> <br />crop. It was also assumed that during the peak use period, no water would <br /> <br /> <br />be applied for deep percolation and that there would be no operational <br /> <br />losses from the canal. The farm efficiency was assumed to be 80 percent <br /> <br /> <br />during peak use periods. The calculations showed that the pumping plant <br /> <br /> <br />needed to be sized to supply the project at the rate of 6.6 gallons-per- <br /> <br /> <br />minute-per-acre at the farm turnout during the critical period. <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />Fish and Wildlife Water Requirements.--The U.S. Fish and Wildlife Service <br />has requested that the project provide supplemental water to the Owens Bay <br /> <br />I <br /> <br />I <br /> <br />31 <br />