The state of California sends 53 members to the House of Representatives, the nation's largest congressional state delegation. Consequently California also has the largest number of electoral votes in national presidential elections, with 55. California's U.S. Senators are Dianne Feinstein, a native and former mayor of San Francisco, and Kamala Harris, a native, former District Attorney from San Francisco and former Attorney General of California. In 1992, California became the first state to have a Senate delegation entirely composed of women.
In 1902, the United States Bureau of Reclamation was established to aid in the economic development of arid western states. One of its major undertakings was building Grand Coulee Dam to provide irrigation for the 600 thousand acres (2,400 km2) of the Columbia Basin Project in central Washington. With the onset of World War II, the focus of dam construction shifted to production of hydroelectricity. Irrigation efforts resumed after the war.
River development occurred within the structure of the 1909 International Boundary Waters Treaty between the US and Canada. The United States Congress passed the Rivers and Harbors Act of 1925, which directed the Army Corps of Engineers and the Federal Power Commission to explore the development of the nation's rivers. This prompted agencies to conduct the first formal financial analysis of hydroelectric development; the reports produced by various agencies were presented in House Document 308. Those reports, and subsequent related reports, are referred to as 308 Reports.
In the late 1920s, political forces in the Northwestern United States generally favored private development of hydroelectric dams along the Columbia. But the overwhelming victories of gubernatorial candidate George W. Joseph in the 1930 Republican primary, and later his law partner Julius Meier, were understood to demonstrate strong public support for public ownership of dams. In 1933, President Franklin D. Roosevelt signed a bill that enabled the construction of the Bonneville and Grand Coulee dams as public works projects. The legislation was attributed to the efforts of Oregon Senator Charles McNary, Washington Senator Clarence Dill, and Oregon Congressman Charles Martin, among others.
In 1948 floods swept through the Columbia watershed, destroying Vanport, then the second largest city in Oregon, and impacting cities as far north as Trail, British Columbia. The flooding prompted the United States Congress to pass the Flood Control Act of 1950, authorizing the federal development of additional dams and other flood control mechanisms. By that time local communities had become wary of federal hydroelectric projects, and sought local control of new developments; a public utility district in Grant County, Washington, ultimately began construction of the dam at Priest Rapids.
In the 1960s, the United States and Canada signed the Columbia River Treaty, which focused on flood control and the maximization of downstream power generation. Canada agreed to build dams and provide reservoir storage, and the United States agreed to deliver to Canada one-half of the increase in US downstream power benefits as estimated five years in advance. Canada's obligation was met by building three dams (two on the Columbia, and one on the Duncan River), the last of which was completed in 1973.
Today the main stem of the Columbia River has 14 dams, of which three are in Canada and 11 in the US. Four mainstem dams and four lower Snake River dams contain navigation locks to allow ship and barge passage from the ocean as far as Lewiston, Idaho. The river system as a whole has more than 400 dams for hydroelectricity and irrigation. The dams address a variety of demands, including flood control, navigation, stream flow regulation, storage and delivery of stored waters, reclamation of public lands and Indian reservations, and the generation of hydroelectric power.
The larger US dams are owned and operated by the federal government (some by the Army Corps of Engineers and some by the Bureau of Reclamation), while the smaller dams are operated by public utility districts, and private power companies. The federally operated system is known as the Federal Columbia River Power System, which includes 31 dams on the Columbia and its tributaries. The system has altered the seasonal flow of the river in order to meet higher electricity demands during the winter. At the beginning of the 20th century, roughly 75 percent of the Columbia's flow occurred in the summer, between April and September. By 1980, the summer proportion had been lowered to about 50 percent, essentially eliminating the seasonal pattern.
The installation of dams dramatically altered the landscape and ecosystem of the river. At one time, the Columbia was one of the top salmon-producing river systems in the world. Previously active fishing sites, such as Celilo Falls in the eastern Columbia River Gorge, have exhibited a sharp decline in fishing along the Columbia in the last century, and salmon populations have been dramatically reduced. Fish ladders have been installed at some dam sites to help the fish journey to spawning waters. Chief Joseph Dam has no fish ladders and completely blocks fish migration to the upper half of the Columbia River system.