Report of the Secretary of the Army
on Civil Works Activities for Fiscal Year 1994
Department of the Army Corps of Engineers
Extract Report of the Walla Walla District
McNary Lock and Dam, Lake Wallula, Oregon and Washington
Existing project. The project includes a dam, powerplant, navigation lock, two fish ladders, appurtenant facilities, and a system of levees and pumping plants. The project provides for slackwater navigation, hydroelectric power generation, recreation, and incidental irrigation. The reservoir has a normal operating range between elevations 340 and 335 msl. Lake Wallula extends upstream about 64 miles and provides slack water to Ice Harbor Lock and Dam. The dam structure is 7,365 feet long and about 183 feet above the streambed. Fish passage facilities include two fish ladders. The powerhouse has fourteen 70,000-kw generating units in operation, for a capacity of 980,000 kw. The spillway dam is 1,310 feet long and the overflow crest is at elevation 291 msl and is surmounted by 22 vertical lift gates, 50 feet wide and 51 feet high, which provide the capacity to pass a design flood of 2.2 million cfs. The navigation lock is a single-lift type with clear plan dimensions of 86 by 675 feet and a 15-foot minimum depth over the sills. A navigation channel (250 feet wide, 14 feet deep, and 32 miles long) is provided from the dam to the mouth of the Snake River. Relocations along the lake included railroad bridges over the Columbia and Snake Rivers in order to eliminate hazards to navigation. Principal project data are set forth in table 39-J.
Construction started May 1947, the project began operation in 1954, and was completed in 1982. Power generation through September 1994 was 240.69 billion kw hours.
Local cooperation. None required.
Operations during fiscal year. Maintenance: Contracts completed for fishway controls and the purchase of fish tank trailers.
Operation and maintenance: During the fiscal year, 5.4 billion kilowatt hours of electrical power were generated by the fourteen generating units. Traffic through the navigation lock consisted of grains, petroleum products, fertilizer, wood products, and miscellaneous cargo; and amounted to 7,450,618 tons during Calendar Year 1993.