Rock Island Dam

The Rock Island Project is located near the geological center of Washington State, on the Columbia River about 12 miles downstream from the city of Wenatchee. By river, the dam is 235 miles below the Canadian border and 453 miles above the mouth of the river at Astoria, Oregon.

Quick facts about the Rock Island Dam:

  • 19 generators
  • First powerhouse – 11 generators
  • Second powerhouse – 8 horizontal shaft (bulb) generators
  • Generator nameplate capacity is 624 megawatts
  • Dam contains 31 spillway gates
  • Original construction of first powerhouse completed in 1933
  • Capacity expanded in 1952-1953 for Alcoa
  • Second powerhouse was constructed in 1979
  • Project license expires in the year 2028

Power from Rock Island Dam flows to major distribution points where it can be delivered to Chelan County customers. Power also flows to the BPA transmission grid, and to the Puget Sound area.