Columbia-Snake River System
U.S. Army Corps of Engineers
The Columbia-Snake River System stretches inland from Astoria, Oregon and the Pacific Ocean to Canada in the north and Wyoming in the east. The navigable portion stretches 465 miles from Astoria to Lewiston, Idaho. In whole, it ranks first in the nation for the transportion and ultimate export of U.S. wheat and barley. Barging is estimated to keep 700,000 trucks off the major highways that serve the region surrounding the Columbia/Snake River System. Every second (on average) 177,900 cubic feet of water passes The Dalles Dam, making it second in size only to the Missouri-Mississippi River system.
The Columbia-Snake River System and the key elements that comprise it are maintained by the U.S. Army Corps of Engineers' Portland and Walla Walla district offices. These elements include the jetties at the mouth of the Columbia, the various dams (used to generate hydroelectric power and maintain flood control) and associated navigation locks, and the navigation channels between them.
The first segment, known as the Lower Columbia, runs from the Pacific to the ports of Portland and Vancouver. Its navigation channel is maintained at a depth of 43 feet and serves a variety of deep-draft cargo and container ships calling on ports such as Vancouver, Kalama, and Longview, Washington. The second segment, known as the Mid-Columbia, runs from the ports of Portland and Vancouver to Pasco, Washington. The Lower Snake runs east from Pasco, Washington, to Lewiston, Idaho, while the Upper Columbia runs north from Pasco into Canada (the Upper Columbia is not navigable).
Completed in 1957, The Dalles Dam is 192 miles upstream from the mouth of the Columbia river. The dam is 1.5 miles wide and falls almost entirely within the state of Washington. Called Lake Celilo after the Celilo Falls swamped by its create, the "reservoir" created behind the dam is 24 miles long. With a total of 22 turbines, the dam's powerhouse can generate up to 2.1 million kilowatts (enough to power approximately 800,000 homes). Just downriver from the Port's barge dock at Dallesport, the navigation locks at The Dalles Dam are 650 feet long and 86 feet wide with a lift of 90 feet.
For more information on the various dams located on the Columbia and Snake Rivers, see the U.S. Army Corps of Engineers' clickable map of the Columbia Basin. Information provided includes the purpose, elevation, and generating capacities of each dam as well as water quality and hydrologic data.
Unlike the Missouri-Mississippi and Colorado river systems, the Columbia-Snake system is capable of storing only half the water it collects. As a result, more water flows year-round through the system than the other controlled systems. For more information on the Columbia-Snake system, read the Columbia River Inside Story [ – 4.1MB], a publication of the Bonneville Power Administration, or Columbia Snake River System [ – 1.4MB], a publication of Pacific Maritime Magazine.