Annual Report of the Chief of Engineers
on Civil Works Activities
Fiscal Year 1989
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 980,000 kilowatt generating capacity by an additional 774,000 kilowatts. 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 will provide protection against heavy rainfall, snowmelt, and thunderstorm floods to the city of Kennewick, Washington.

Reevaluation of the project economics due to hydrology modifications resulted in a revised General Design Memo No. 2. The GDM has been forwarded to the Washington Level Review Board for approval. Fiscal Year costs were $159,360.

The total estimated Federal and non-Federal project cost is $9,300,000. The estimated Federal cost is $7,000,000.

Local cooperation. Non-Federal sponsors shall pay 25 percent of the total project cost or an estimated $2,300,000 in cash or materials.