Rock Island: Columbia River, WA

The Rock Island Hydroelectric Project is located near the geographical center of Washington state on the Columbia River. Development began in January, 1930; four generating units were operational in 1933. Six additional generating units were added to the initial powerhouse beginning in 1951. Work was completed on this phase of construction in 1953. A second powerhouse was constructed from 1974 through 1979. This powerhouse contains eight ‘bulb type’ turbine generating units, which are mounted horizontally in the water passage as opposed to the traditional vertical orientation. The bulb turbine generating units were the first installed in the United States and were the largest in the world when installed.

The Rock Island Project reservoir extends upriver about 20 miles. Chelan County Public Utility District has constructed several parks along the reservoir shoreline for public use.