List of dams in the Columbia River watershed
Name Height Capacity ( MW ) Province/State ( s ) Year of completion Owner Reservoir formed
Carmen Diversion Dam 17 ft ( 5.2 m ) 0 Oregon 1963 Eugene Water & Electric Board Carmen Reservoir
Trail Bridge Dam 90 ft ( 27 m ) 10 Oregon 1963 Eugene Water & Electric Board Trail Bridge Reservoir
Smith Dam ( Smith River ) 250 ft ( 76 m ) 104.5 Oregon 1963 Eugene Water & Electric Board Smith Reservoir
Cougar Dam ( South Fork ) 425 ft ( 130 m ) 25 Oregon 1963 Army Corps of Engineers Cougar Reservoir
Blue River Dam ( Blue River ) 270 ft ( 82 m ) 0 Oregon 1969 Army Corps of Engineers Blue River Reservoir
Leaburg Dam 20 ft ( 6.1 m ) 15.9 Oregon 1929 Eugene Water & Electric Board Leaburg Reservoir
Walterville Dam 24 ft ( 7.3 m ) 9 Oregon 1911 Eugene Water & Electric Board Walterville Reservoir
Main stem Columbia River dams -- Willamette River dams
Dams are listed in order from headwater ( Clear Lake , OR ) to mouth ( Willamette River , OR ) .
There are more than 60 dams in the Columbia River watershed in the United States and Canada. Tributaries of the Columbia River and their dammed tributaries, as well as the main stem itself, each have their own list below. The dams are listed in the order as they are found from source to terminus. Many of the dams in the Columbia River watershed were not created for the specific purposes of water storage or flood protection. Instead, the primary purpose of many of these dams is to produce hydroelectricity. As can be seen in the lists, these dams provide many tens of gigawatts of power. Major dam construction began in the early 20th century and picked up the pace after the Columbia River Treaty in the 1960s, by the mid 1980s all the big dams were finished. Including just the dams listed below, there are 60 dams in the watershed, with 14 on the Columbia, 20 on the Snake, seven on the Kootenay, seven on the Pend Oreille / Clark, two on the Flathead, eight on the Yakima, and two on the Owyhee. Averaging a major dam every 72 miles (116 km), the rivers in the Columbia watershed combine to generate over 36,000 megawatts of power, with the majority coming on the main stem. Grand Coulee Dam is the largest producer of hydroelectric power in the United States, generating 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.