Report of the Secretary of the Army
on Civil Works Activities for Fiscal Year 1998
Department of the Army Corps of Engineers
Extract Report of the Walla Walla District
Ice Harbor Lock and Dam-Lake Sacajawea, Washington
Location. On the Snake River, 9.7 miles above river mouth at head of Lake Wallula (McNary Reservoir) and 12 miles east of Pasco, Washington.
Existing project. The project includes a dam, powerplant, navigation lock, two fish ladders, and appurtenant facilities. The project provides navigation, hydroelectric power generation, recreation, and incidental irrigation. The reservoir has a normal operating range between elevations 440 and 435 msl. Lake Sacajawea extends upstream about 31.9 miles and provides slackwater to Lower Monumental Lock and Dam. The dam structure is about 2,822 feet long and about 130 feet above the streambed. The fish passage facilities include two fish ladders. Powerhouse has three 90,000 kw units and three 111,000 kw generating units in operation for a capacity of 603,000 kw.
The spillway dam is 590 feet long and overflow crest at elevation 391 msl is surmounted by 10 radial gates, 50 feet wide and 52.9 feet high, which provide the capacity to pass a design flood of 850,000 cubic feet per second. The deck is at elevation 453 msl, and provides a service road and track for a gantry crane. The navigation lock is a single-lift type with clear plan dimensions of 86 by 675 feet and a 16-foot minimum depth over the sills. A navigation channel 250 feet wide, 14 feet deep, and 41.6 miles long is provided from the mouth of the Snake River to the dam and from the dam to Lower Monumental Lock and Dam. Principal data are set forth in table 39-J.
Construction of the original project started in December 1955, was placed in operation in 1961, and was completed in 1971. Construction of the additional generating units was started in 1971 and completed in 1981. Power generation through September 1998 was 78.71 billion kw hours.
Recreation areas on Lake Sacajawea include 11 picnic/day-use sites, 4 camping areas, 7 areas with boat launching, and 4 swimming areas. Total visitation on Lake Sacajawea for the fiscal year was 437,600.
Local cooperation. None required.
Operations during fiscal year. Maintenance: Continued repair contracts for navigation lock gate. Completed repair of Unit 5. Operation and Maintenance: During the fiscal year, 2.0 billion kw hours of electrical power were generated by the six generating units. Traffic through the navigation lock consisted of grains, petroleum products, fertilizer, wood products, and miscellaneous cargo; and amounted to 4,206,988 tons during Calendar Year 1997. Fiscal year costs were $7,064,312.