Bonneville

U.S. Army Corps of EngineersMultnomah CountyBPAT

Bonneville Dam is a conventional hydroelectric plant in Multnomah County, Oregon, with 16 operating generating units and a combined nameplate capacity of 979.8 MW. The dam sits on the Columbia River about 40 miles east of Portland, at River Mile 146.1, forming the border between Oregon and Washington. It was built and is operated by the U.S. Army Corps of Engineers, with the power it produces marketed and sold by the Bonneville Power Administration. The plant consists of a first powerhouse whose ten original units entered service between 1938 and 1944 (later rewound to 62.1 MW units) and a second powerhouse of eight 66.5 MW units completed in 1981, plus a small 13.1 MW auxiliary unit that powers the fish-ladder water-supply system.