Umatilla Basin Project Act

Umatilla Basin Project Act - Authorizes the Secretary of the Interior to construct, operate, and maintain the Umatilla Basin Project, Oregon, in accordance with the report of the Secretary. Declares the purpose of such project to mitigate losses to anadromous fishery resources and continuing water service to the Hermiston, West Extension, Westland, and Stanfield Irrigation Districts, or any other entity which participates in the project water exchange.

Declares the principal works of such project to consist of: (1) pumping plants and related conveyance and distribution features; (2) works incidental to existing irrigation systems necessary to accomplish a water exchange; (3) fishery resources mitigation measures; and (4) programs to monitor and regulate project operations and evaluate fishery resource mitigation measures. Requires project features to be integrated and coordinated with the existing Umatilla Project.

Requires the Administrator of the Bonneville Power Administration to provide for project power needed to effect the water exchange with irrigation districts in accordance with the Columbia River Basin Fish and Wildlife Program established under the Pacific Northwest Electric Power Planning and Conservation Act. Requires the cost of project power to be credited to fishery restoration goals of the Program.

Establishes the procedure for the Secretary of the Treasury to determine the interest rate for construction charges.

Requires fishery resource facilities to be constructed, operated, and maintained in accordance with the Federal Water Project Recreation Act, except that costs allocated to the mitigation of anadromous fish species shall be nonreimbursable.

Directs the Secretary of the Interior to enter into agreements which specify appropriate non-Federal obligations for the operation and maintenance of project facilities.

Authorizes appropriations to the Secretary for the operation and maintenance of the existing West Extension Irrigation District pumping facility as an interim measure to provide flow augmentation in the Umatilla River.

Provides for the crediting of non-Federal costs for fishery resource improvements.

Provides that when project pumping capacity is available in excess of that needed for fishery resource benefits, such capacity shall be available to eligible irrigation districts participating in the project. Requires the irrigation districts to pay the costs of such power which shall be provided from the Federal Columbia River power system.

Declares such irrigation districts eligible for financial assistance under the Rehabilitation and Betterment Act for water conservation purposes and improvements to water supply systems.

Authorizes appropriations for the Secretary to purchase land, water rights, or other interests for the benefit of fishery resources consistent with the purposes of this Act.

Authorizes construction appropriations.