Annual Report of the Chief of Engineers
on Civil Works Activities
Fiscal Year 1988
Department of the Army Corps of Engineers
Extract Report of Walla Walla District

Preconstruction, Engineering and Design

McNary Lock and Dam (Second Powerhouse), Oregon and Washington

McNary Second Powerhouse is a proposed addition on the south shore of McNary Lock and Dam on the Columbia River near Umatilla, Oregon. The project will increase the present 1127 megawatt generating capacity by an additional 742 megawatts. Provisions are included for compensation of negative impacts on fish and wildlife. The project is estimated to cost $667,000,000 at October 1, 1986 price levels.

The General Design Memorandum Phase I was prepared under the Water Resource Development Act of 1976, Public Law 94-587, and submitted to the Secretary of the Army on July 1, 1981.

Studies were initiated in FY 1982 and continued through FY 1984 on the General Design Memorandum Phase II and the Powerhouse Preliminary Design Report. There has been no further design activity on the project. The project was authorized for construction in the Water Resources Development Act of 1986.

Zintel Canyon Dam, Washington

The proposed project consists of a roller compacted concrete dam 90 feet high with uncontrolled spillway and a fixed maximum release outlet works that would create a detention reservoir of 1,260 acre-feet of capacity. The storage comprises 860 acre-feet for flood control and 400 acre-feet for sediment. In addition, the project also includes a conduit with a capacity of 400 cfs and a dike and floodgate across the Union Pacific Railroad to protect downtown Kennewick, Washington. The plan of improvement would provide protection against heavy rainfall, snowmelt, and thunderstorm floods to the city of Kennewick, Washington. Estimated Federal project cost is $6,665,000.

Reevaluation of the project was initiated to revise the General Design Memo No. 2 with fiscal year costs of $54,373. The project was authorized for construction by Resolutions of the House and Senate Committees on Public Works, December 15, 1970, under Section 201, Flood Control Act of 1965 (PL 298-89). Review Report submitted to Congress in February 1970.