Annual Operating Plan for Colorado River Reservoirs 1998

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harvested from these rearing areas and then released to the lake. The suckers grow very quickly, usually exceeding ten inches in length by September. Senator Wash and Laguna Reservoirs Operations at Senator Wash Reservoir allow regulation of water deliveries to United States water users and Mexico downstream at Imperial Dam. The reservoir is operated to meet water user demands when necessary and to prevent Colorado River flows from exceeding Mexican Treaty requirements at Morelos Dam. This includes excess flows in the river caused by water user cutbacks and sidewash inflows. Operational objectives at and below Imperial Dam are to meet water user demands, to conserve water, to control sediment, and to maintain the river channel. Releases from Imperial Dam are regulated by Laguna Reservoir to conserve water, to meet all or part of Mexico's water demands, and to maintain river flows downstream near Yuma. Laguna releases combined with agricultural seepage and drainage provide a continuous live stream serving recreational and fish and wildlife purposes. Larger releases from Laguna Dam are generally due to excess water from rain, flooding upstream, or from rejected water orders due to rain. These higher releases serve to maintain the river channel capacity. This occasional practice reduces channel maintenance expense without impairment of water conservation or power production. Yuma Desalting Plant The Yuma Desalting Plant was not operated in 1997, and will not be operated in 1998 as funding is currently not available for full -scale operation. Most of the damage to the Main Outlet Drain (MOD), the Main Outlet Drain Extension (MODE), and the bypass drain from the 1993 Gila River flood has been repaired. Some damage to the MODE near the Gila River confluence will be repaired at a later date. All Wellton- Mohawk Irrigation and Drainage District drainage flows should be diverted into the MODE in 1998. The test train, used for research and the building's water service, will be run throughout 1998. The test train uses about one million gallons per day of drainage water taken from the MODE or pumped from an on -site well. Colorado River Channel Aggradation below Gila River Confluence The 1993 Gila River flood deposited large amounts of sediment in the lower Colorado River above and below Morelos Dam. This has substantially reduced the river's capacity to carry flood flows, raised groundwater levels, and has caused operational problems with the delivery of Treaty water to Mexico above Morelos Dam. The Yuma Area Office has been working with local irrigation districts, the International Boundary and Water Commission, Native American Tribes, local environmental organizations, local governments, and other State and Federal agencies to develop a project proposal to solve the problems created by the channel aggradation. September 3, 1997 14