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I I t\lohavc and Havasu Reservoirs are scheduled to be drawn down in the late summer and wimer months 10 pro\"ide storage space for local stonn runoff and will be filled in the spring to meet higher summer \l,'ater needs. This drawdown will also correspond with maintenance at both Davis and Parkerpowerplams which is scheduled for September through February. During 2003. Lake ;\foha\'e will continue to be operated under the constraints as described in the Biological and Conference Opinion on Lower Colorado Riwr Operations and :>'faintenance. Reclamation. as provided in the Interim Surplus Guidelines Record of Decision. will continue these existing operations in Lake ;...loha\"c that benefit native fish through the effective period of the Interim Surplus Guidelines and \vill explore additional ways to provide benefits to nati\'e fish. The nonnal filling pattern of these two reservoirs coincides well with the fishery spawning period. Since lake elevations will be typical of previous years. nomlal conditions are expected for boating and other recreational uses. I I I I I I Reclamation is the lead agency in the i\ative Fish Work Group. a multi.agency group of scientists attempting to augment the ageing stock of the endangered razorback sucker in Lake :V1ohave. Larval suckers are captured by hand in and around spawning areas in late winter and early spring for rearing at Willow Beach Fish Hatchery below Hoover Dam. The follo....,ing year. one year old suckers are placed into predator-free. lake.side backwaters for rearing through the spring and summer. When the lake is nonnaH)' drawn down during the fall. these fish are harvested from these rearing areas and Ihen released to the lake. The suckers grow very quickly. usually exceeding ten inches in length by Sep!ember. I I Senator "'ash and Laguna Resenoirs I Operations at Senator Wash Reservoir allow regulation of water deliveries to United States and tv1exican water users downstream oflmperial Dam. The resCTvoir is utilized as an ofT-stream storage facility to meet downstream water demands and to conserve water for future uses in the United States and the scheduled uses of Mexico in accordance with the Treaty obligation. Senator Wash Reservoir is the only major storage facility below Parker Dam. Senator Wash Dam is located approximately 142 river miles do\vnstream of Parker Dam. Operational objectives are 10 store excess nows from the river which have been caused by water user cutbacks and side wash inOows due to rain. Stored waters arc utilized to meet irrigation. recreational. and TrealY demands. Elevation restrictions on Senator Wash Reservoir reduce the nexibility of water slOrage in the lower reaches of the rivcr. Since August of 1992. a restriction at elcvation 240.0 feet. mean sea level. at Senator Wash Reservoir was put in place. This was due to potential piping at West Squaw Lake Dike and Senator Wash Dam. Aller removing a rock taBus pile and replacing it with a filter blanket at West Squaw lake dike during the first part of CY 2000. a reservoir fill test was started September 15 and concluded on October 19. :WOO. The test had to be stopped due to piping concerns at West Squaw Lake Dike_ During most ofCY 2000. Senator Wash was not available to regulate rivcr Oows and excess flows to Mexico exceeded 300.000 acre-feet for the year. Since the fill test in CY 2000. a new elevation restriction at 235 feet was put in place. and excess flows to Mexico in CY 2001 dropped to about 200.000 acre. feet. In CY 2002 a new filter blanket was placed at West Squaw Lake Dike. additional instrumentation was put in place and another fill test was conducted from April through July 7. 2002. Senator Wash was not available for river regulation essentially from the first ofCY 2002 until July 7.2002. Due to the success of this fill test the elevation restriction was raised back to e1e\-ation 240 feet on July 8.2002 with some operational restrictions and monitoring I I I I I I I December 13. 2002 IS I