Prominent dams of the Columbia River Basin. Color indicates dam ownership:
U.S. Federal government
State, provincial, or local government
(Please note, the file linked through the image contains a much more detailed listing of tributary dams than this article.)
What follows are four lists of dams that can be found in the Columbia River watershed. The major tributaries of the Columbia, as well as the main stem itself, each have their own list. The dams are listed in the order as they are found from source to terminus. A large number of the dams in the Columbia River watershed are not created for water storage or flood protection. Instead, the primary purpose of these dams is hydroelectric power production. As can be seen in the lists, these dams provide a massive amount of power.
Major dam construction began in the early 20th century, and finished toward the end of the same century. Including just the dams listed below, there are forty-seven dams in the watershed, with fourteen on the Columbia, sixteen on the Snake, eight on the Kootenay, five on the Pend Oreille, two on the Flathead, and two on the Clark Fork. Averaging a major dam every seventy-two miles, the rivers in the Columbia watershed combine to create 35,936.6 megawatts of power, with the majority coming on the main stem. Grand Coulee Dam is the largest producer of hydroelectric power in the nation, creating 6,809 megawatts, over one-sixth of all power in the basin.
In addition to providing ample power for the people of the Pacific Northwest, the reservoirs created by the dams have created numerous recreational opportunities, including fishing, boating, and windsurfing. Furthermore, by creating a constant flow and consistent depth along the river channel, the series of locks and dams have allowed for Lewiston, Idaho to become the furthest inland seaport on the west coast of the United States. Despite the numerous benefits to humans that the dams have given, a number of environmental consequences have manifested as a result of the dams, including a negative impact on salmonid populations of the basin.
The organization of the following lists begins with the Columbia and is followed by its tributaries in order of length. Additionally, the table of contents below is indented to indicate tributary status of each river.