OpenStreetMap (new tab)

Google Map (new tab)

Overview

Owned by the muncipally-controlled Seattle City Light and Power Company, the Skagit River Hydroelectric Project operated three separate dams on different points along the Skagit River in Whatcom County, WA, near the town of Newhalem. The three dams--Gorge Dam, Diablo Dam, and Ruby Dam (later renamed "Ross Dam" for the project's manager, James Delmage Ross [1872–1939])--were constructed at intervals between the early 1920s and the early 1950s.

Building History

Seattle City Light and Power developed this dam project between 1927 and 1930, to provide power for the City of Seattle. At the time, Seattle's power needs were beginning to outstrip the utility's generating capacity. By the 1920s, the cities of Seattle and Tacoma had reciprocal power generation agreements; in the event one needed power, they could call on the other's excess capacity, if it existed. Power requirements rose throughout the 1920s, and by 1929, a drought had created very narrow margins between hydroelectric power supply and demand for the utilities of both cities. In 11/1929, Seattle's utility hoped to buy (without success) power from the U.S.S. Lexington moored in the harbor to augment its depleted supply. Without this additional power from the US Navy, City Light threatened that it would have to cut power to all suburban customers located outside the Seattle city limits. (See "Suburbanites' Power Service Will Be Halted," Seattle Daily Times, 11/29/1929, pp. 1 and 16.)

As a result of consistent increases in demand, Seattle City Light and Power undertook the construction of three dams along the Skagit River in Whatcom County, WA, between 1921 and 1953. Construction on the first, Gorge Dam, began in 1921 and delivered power three years later. Diablo Dam, a considerably larger project, took nine years to complete before the start of construction and power delivery. Diablo Dam's construction was completed in 1930, but power generation did not occur until six years later. The final dam, Ruby Dam (aka Ross Dam), was planned, like Diablo, on a large scale. Work began on it in 1937, with the first phase being completed three years later. Second and third phases of the Ruby Dam portion were finished in 1953.

PCAD id: 5333