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<br />1),1),0 8 ~ 1 <br /> <br />,'" ~.' <br /> <br />overseen by the field office staff, is the requirement to operate <br />the major storage reservoir, Lahontan Reservoir, at a reduced level <br />to reduce operational spills and evaporation losses. During <br />previous years, the 363.9 million m' (295,000 acre-foot) reservoir <br />was operated in a manner that kept it as full as possible during <br />the entire year. This required significant diversions from the <br />Truckee River in. all but the wettest years when the Carson River <br />produced enough water to keep the reservoir full. <br /> <br />This practice often resulted in uncontrolled spills during the <br />spring runoff due to the high level of the reservoir going into the <br />runoff season. To reduce this problem of spilling water that could <br />not be used in the irrigation project, the OCAP requires the <br />reservoir to 'be operated at a lower level, usually below 265.2 <br />million m' (215,000 acre-feet). The exact allowable storage level <br />during the runoff months of January through June is determined <br />monthly by using data from existing storage. volume, expected <br />irrigation demand, and expected runoff volume of the Carson River <br />for the month. This data is used to determine the expected end of <br />month storage levels for" Lahontan Reservoir, which in turn is used <br />to determine the amount of water allowed to be diverted from the <br />Truckee River that month. The storage contents during the <br />remainder of the year are restricted to levels that allow enough <br />carryover storage to keep shortages at minimal levels in case of a <br />drought the following year, but also keep spills at minimum levela. <br />if a wet year follows. The storage level restrictions were <br />developed using a computer program that uses 80 years of historical <br />data to predict future supplies under various weather conditions~ <br />One major reason reservoir levels can be reduced without causing a <br />significant increase in water shortages during dry years is that <br />the demand for water will decrease as the efficiency of the project <br />is improved. In other words, less water lost means less water <br />needed in storage. <br /> <br />One. of the first measures considered and acted upon by the Bureau's <br />field'office and the district was reducing the .levels at which the <br />equalizing reservoirs on the project are operated. . The Newlands <br />Project has four small equalizing reservoirs scattered throughout <br />the project lands. These reservoirs. act as storage areas where <br />water is stored during times of low water demand from the <br />irrigators and then released during times of high demands. <br />Therefore, they reduce the need to make frequent adjustment of <br />flows bein~ released from Lahontan, the main storage reservoir. <br />The largest' of these equalizing reservoirs is. Sheckler with a <br />capacity of 19.1 million m' (15,500 acre-feet) and a surface area <br />of 1,093 ha (2,700 acres) when full. Evaluation of the manner in <br />which the reservoir and surrounding canal systems were being <br />operated revealed that the reservoir could be operated at a much <br />lower level and still meet system demands. The reservoir was <br />operated at a lower capacity of approximately 3.2 million m' (2,600 <br />acre-feet) with a resulting reduction in surface area of 283 ha <br />(700 acres) , This results in a savings of approximately 12.3 <br /> <br />5 <br />