Skagit River Hydroelectric Project


The Skagit River Hydroelectric Project is a series of dams with hydroelectric power-generating stations on the Skagit River in northern Washington State. The project is owned and operated by Seattle City Light to provide electric power for the City of Seattle and surrounding communities.
In 2012, hydro-electric dams provided approximately 89.8 percent of the electricity used in Seattle. The Skagit Hydroelectric Project alone accounts for about 20 percent of Seattle City Light's electricity.
The three major dams in the Skagit River Project are Gorge Dam, Diablo Dam, and Ross Dam. The dams are located in Whatcom County above the town of Newhalem, which lies just west of North Cascades National Park. Ross Lake, formed by Ross Dam extends into British Columbia, which is 20 miles upriver from the dam. Ross Lake National Recreation Area surrounds the lake.
Construction of Gorge Dam began in 1921 and the first power was delivered to Seattle in 1924. The cost of the dam was $13 million. In 1961 a new Gorge High Dam was completed to replace the original Gorge Dam.
This dam was featured in Alan Pakula's 1974 thriller The Parallax View, starring Warren Beatty.
Construction of Diablo Dam was begun in 1927, five miles upstream from Gorge Dam. Diablo Dam was completed in 1930, and at that time was the tallest dam in the world at 389 feet until Owyhee Dam was built. However, the dam produced no electricity for Seattle until 1936.
Construction of Ruby Dam at the Rip Raps below Ruby Creek began in 1937. This dam was renamed Ross Dam after the death of James Delmage Ross, the superintendent of the Skagit River Project. Construction of Ross Dam was to take place in three stages and the first stage was completed in 1940. The second and third stages were completed in 1953 when the dam was built to its final height of 540 feet.
All three dams were listed in the National Register of Historic Places.

Hydroelectric power capacity