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<br />! <br />I <br /> <br />Flood Control <br /> <br />Lake Mead is operated in accordance with updated llood <br />control regulations which are specified in the Field Working <br />Agreement between Reclamation and the Corps of <br />Engineers, signed in 1982. The regulations stipulate the <br />minimum release levels needed from Lake Mead to route <br />the reasonable maximum inflow. The reasonable maximum <br />inflow is the estimated inflow volume that, on the average, <br />will not be exceeded 19 out of 20 times. This volume is <br />derived by adding an "uncertainty" term to the most probable <br />runoff forecast. In 1983, unusual hydrometeorological events <br />resulted in unprecedented large forecasting errors. <br />Subsequent reassessment of the estimate of the "uncertainty" <br />term led to adoption of larger values for use in determining <br />the reasonable maximum inflow in 1984 and thereafter. <br /> <br />Due to the amount of vacant storage space in Colorado <br />River reservoirs, no llood control releases are anticipated in <br />1995, but in future years, as Lake Mead refills and llood <br />control releases are again required by the Hoover Dam <br />Hood Control Regulations, consideration will be given to <br />making those releases over the fall and winter months to <br />avoid high flow rates during the January to July runoff <br />season. This distribution of water reduces the chance of <br />bypassing hydroelectric powerplants below Hoover Dam and <br />avoids the adverse impacts of higher llood control releases <br />on fish and wildlife, recreation, water quality, and river <br />stabilization. <br /> <br />Routine maintenance of bankline protection facilities were <br />carried out during water year 1994. As in the previous years, <br />greater tban normal bankline repair was necessitated in part <br />by increased wave action from boating and other recreational <br />river traffic. During water year 1994, the river channel in <br />the Lower Basin has remained in good balance, neither <br />aggrading nor degrading significantly in any particular reach. <br /> <br />Total Colorado River reservoir system storage at the start of <br />water year 1994 was approximately 59.6 billion cubic meters <br />(48.3 million acre-feet) and about 55.0 billion cubic meters <br />(44.6 million acre-feet) at the end of the water year, <br />representing a 45 billion cubic meters (3.7 million acre-feet) <br />decrease in total remaining available reservoir space. <br /> <br />During water year 1995, the Corps of Engineers flood <br />control facilities; Painted Rock (Gila River) and Alamo <br />Reservoirs are expected to be operated in accordance with <br />Reclamation project releases and established flood control <br />criteria to maximize the available flood control space in their <br />respective reservoirs. <br /> <br />-------~------------- - -~ --------- ------------. <br /> <br />'22 <br />