Ross Dam

Prior to construction of the dam the Skagit Gorge upstream of the dam was a wild, free flowing, completely undeveloped area. The canyon held an intact ancient forest of Douglas Fir, Western Hemlock and Western Redcedar, estimated to be millable into up to 340 million usable board feet of timber. With the creation of the Skagit River Hydroelectric Project in the 1910s, the first two dams, Gorge Dam and Diablo Dam, were constructed downstream of the Ross Dam site. In 1937, construction began on the dam, originally slated to be called Ruby Dam, on the first two of four planned construction phases. The name originates from Ruby Creek, a Skagit River tributary that flows southwest to meet the Skagit just upstream of the dam site.[2] By 1940, phases 1 and 2 of the dam were complete, and the dam stood 305 feet (93 m) above the river. While the reservoir filled, the Decco-Walton Logging Company was formed in 1945 with the awarding of a contract from Seattle City Light. Decco-Walton logged the Skagit Gorge as Ross Lake slowly rose, and floated logs up the river to British Columbia, where it was hauled to the Fraser River. By the time Ross Lake filled, only 30 million board feet remained in the basin, less than 10% of the original timber.[2][3][4]

Ross Dam third construction phase, 1947

In 1939, superintendent of the Skagit Hydroelectric Project James Delmage Ross has died, so Ruby Dam was renamed Ross Dam in his memory. In 1943 a consortium of contractors including Morrison-Knudsen, which had previously participated in construction of Hoover Dam, began new construction on the dam ultimately raising its height to 475 feet (145 m).[5] Energy demands during World War II coincided with an energy shortage in Seattle, requiring that the dam be constructed quickly, but the dam did not generate any power until many years after the war ended.[6] This third phase was finished in 1949, to 540 feet (160 m). This height would cause the reservoir at full pool to extend slightly past the Washington-British Columbia border. The reservoir, however, did not fill past the national border until 1954. As compensation for the flooded land, which totals about 500 acres (2.0 km²), Seattle City Light paid the Province of British Columbia $250,000, as well as an annual payment of $5,000. Two years prior to the reservoir reaching full pool, construction of the Ross Dam power plant began, and two turbines first went on line in 1956, generating 360 MW of power. Another two generators were added later, increasing the capacity to its current 460 MW.[2]

The upper map shows what the dimensions of the reservoir would have been if the high dam had been built. The lower map shows the existing dimensions of the reservoir. Dam is at left in both maps.

A controversy later arose over the planned fourth stage of the construction of Ross Dam. This argument over land became known as the High Ross Dam Controversy. The dam was built with the potential to be raised 125 feet (38 m) further, bringing the total height of the dam to 665 feet (203 m) and raising the reservoir to approximately 1,725 feet (526 m) above sea level. The stepped "concrete waffle" facing on the front of the dam was designed to accommodate this addition to the height.[6] This would have flooded land into Canada approximately 3 miles (4.8 km) further, also extending up the Klesilkwa River, a Skagit River tributary, and provided the opportunity to generate about 272 MW of extra power, bringing the generating capacity to 732 MW.[4][6] It wasn't until the 1970s when the High Ross project was finally ended. On the US side, the North Cascades Conservation Council inventoried the ancient forest of Big Beaver Creek which would have been flooded, and showed that City Light's statements that no unique forest environments would be lost were not true. On the Canadian side the raising of the dam was halted primarily by the extensive work by Curley Chittenden - logger turned environmentalist, who worked tirelessly to rally opposition to this additional flooding of the upper Skagit River basin. Ultimately a treaty was signed between the City of Seattle and Province of British Columbia to supply Seattle with the equivalent amount of power from other, existing dams in British Columbia in exchange for Seattle not raising the dam. The Skagit Environmental Endowment Commission was created at this time to oversee joint USA/Canada stewardship of the upper Skagit River watershed.