McNary Dam

McNary Dam is a 7,365 foot (2,245 meter) long hydroelectric dam spanning the Columbia River. It joins Umatilla County, Oregon with Benton County, Washington, 292 miles (470 kilometers) upriver from the mouth of the Columbia at Astoria, Oregon. It is operated by the United States Army Corps of Engineers' McNary Lock and Dam office. The closest city on the Oregon side is Umatilla, Oregon; on the Washington side the closest town is Plymouth, Washington . The dam was originally to be named the Umatilla Dam, but the River and Harbor Act of 1945 , authorizing the construction, also renamed the dam in honor of the late Senator Charles L. McNary.

The dam provides for slackwater navigation, hydroelectric power generation, recreation, wildlife habitat, and incidental irrigation. The initial phase of construction began in 1947, and was completed in 1954. Activation of all generating units was completed in 1957. Its capacity is 980,000 kW. There are two fish ladders for salmon and steelhead passage, one on each shore of the dam. The Washington side also has a 86 foot (26 meter) wide, 683 foot (208 meter) long navigation lock that lifts boats an average of 75 feet (23 meters). The reservoir behind the dam, Lake Wallula , extends 64 miles (103 kilometers) up the Columbia to the US DOE Hanford Site. It also extends up the Snake River to the Ice Harbor Dam .

See also

• Hydroelectric dams on the Columbia River

External link

• US ACE page