To authorize certain elements of the Yakima River Basin Water Enhancement Project, and for other purposes.

Directs the Secretary of the Interior to establish and administer a Yakima River Basin Water Conservation Program. Authorizes the Secretary to make grants to eligible entities to carry out this Act.

Prohibits conserved water resulting from the expenditure of Federal funds from being used to expand irrigation in the basin, except on the Yakama Indian Reservation. Directs the Secretary to establish the Yakima River Basin Conservation Advisory Group. Requires entities to submit water conservation plans to the Secretary for approval in order to participate in the conservation program. Authorizes appropriations.

Provides for the implementation by the Yakama Indian Nation of: (1) an irrigation demonstration project on the Yakama Indian Reservation that shall provide for the construction of distribution and on-farm irrigation facilities to use water savings resulting from system improvements to the Wapato Irrigation Project; and (2) a Toppenish Creek corridor enhancement project to demonstrate integration of management of agricultural, fish, wildlife, and cultural resources to meet tribal objectives. Authorizes appropriations.

Details the instream flows the Secretary is required to provide through the Yakima Project Superintendent, requiring flow increases (obtained through voluntary sale and leasing of water or water rights or conservation measures) to facilitate anadromous fish migration.

Directs the Secretary to report to the Congress on whether the water supply available for irrigation is adequate to sustain the agricultural economy of the Yakima River basin.

Authorizes appropriations for: (1) modifying the radial gates at Cle Elum Dam to provide additional storage capacity in Lake Cle Elum; (2) providing for shoreline protection of the Lake; (3) constructing juvenile fish passage facilities at the Dam; (4) operation and maintenance responsibilities of the Federal Government for the Dam; and (5) environmental mitigation.

Provides for the enhancement of water supplies for Yakima River Basin tributaries for fish and wildlife and irrigation purposes. Requires a study to determine the measures to be implemented to enhance water supplies for such purposes on Taneum Creek. Authorizes appropriations for such enhancement and for the Taneum Creek study.

Authorizes appropriations to provide for electrification to enhance instream flows by eliminating the need to divert water to operate the hydraulic turbines which pump water to the Kennewick Irrigation District.

Requires the Secretary to ensure that the irrigation water supply for the District shall not be affected by conservation, electrification, or subordination pursuant to this Act and any conservation measures shall be replaced by water developed through subordination or electrification.

Authorizes appropriations to augment Kachess Reservoir stored water supplies from flows of Cabin and Silver Creeks which are excess to system demands.

Requires the stored water supply resulting from the construction of facilities under this section to be used to: (1) enhance the water supply of the Kittitas Reclamation District and the Roza Irrigation District in years of proration; and (2) facilitate reservoir operations in the Easton Dam to Keechelus Dam reach of the Yakima River for the propagation of anadromous fish.

Authorizes appropriations for the modification of the discharge facilities of Kachess Dam to improve reservoir operations for anadromous fish enhancement.

Directs the Secretary to develop an interim operating plan for providing a general framework within which the Yakima Project Superintendent operates the Yakima Project. Authorizes appropriations.

Authorizes appropriations for environmental compliance activities.