HYDROELECTRICITY is electricity generated by moving water, usually at power plants in dams on major RIVERS. Water is backed up in reservoirs by the dams to obtain a steady flow and to increase the head (the height the water falls to the turbines). Because of the abundance of running water in BC, hydro quickly replaced other energy sources, principally steam. Electricity now supplies 20% of BC's energy requirements, 92% generated by hydro.

In 1897 a group of entrepreneurs formed the WEST KOOTENAY POWER & LIGHT CO to provide electrical power to MINES in ROSSLAND. The power dam it put into operation at lower BONNINGTON FALLS on the KOOTENAY R in 1898 was the first hydroelectric facility in BC. It was followed closely by a plant on the GOLDSTREAM R north of VICTORIA, owned by the BC ELECTRIC RWY CO (BCER); the facility went into operation later that same year, as the first hydro plant on the coast. The BCER next built a generation plant at BUNTZEN LK, which began supplying electricity to VANCOUVER at the end of 1903, and in 1911 it opened a plant at JORDAN R, which eventually replaced the Goldstream plant as the main power supplier to Victoria. There were other private developments on rivers around the province, mainly to supply power for industrial projects of one kind or another, but over the next 50 years BC Electric became by far the largest supplier of electricity to homes and industries, especially in the densely populated Lower Mainland. In response to BC Electric's dominance, the provincial government created the Public Utilities Commission (PUC) in 1938, to supervise and regulate utilities. (In 1973 the PUC was reconstituted as the BC Energy Commission and then in 1980 as the BC Utilities Commission.) Post-WWII, the demand for electricity grew dramatically and the province's main producers responded by expanding their generating capacity. The provincial government created the BC POWER COMMISSION to provide electricity to rural customers not being served by other suppliers. Meanwhile BC Electric began in 1948 to produce power from an expanded BRIDGE R development; it remained the largest hydro development in BC for the next 20 years. Another huge development was the KEMANO project, built in the early 1950s by ALCAN ALUMINUM CO. The company constructed the KENNEY DAM on the NECHAKO R to divert its headwaters westward through a tunnel in the COAST MTS to Kemano. There it was used to generate electricity that was carried by transmission lines 75 km north to power the aluminum smelter at KITIMAT.

In the 1960s the SOCIAL CREDIT government of W.A.C. BENNETT embarked on its TWO RIVERS POLICY of hydroelectric development, which saw the construction of large power dams on the PEACE and COLUMBIA rivers, dramatically increasing electrical output in the province. In 1961 Bennett announced the nationalization of BC Electric; the following year he merged it with the BC Power Commission to form BC HYDRO AND POWER AUTHORITY, the government's chosen instrument for carrying out its ambitious plans. With the signing of the COLUMBIA RIVER TREATY in 1964, Bennett was able to proceed with the construction of a series of power and storage dams, including the BENNETT DAM on the Peace R (1968) and the DUNCAN (1967), KEENLEYSIDE (1968) and MICA (1976) dams on the Columbia R. By 1980 Hydro was capable of producing almost 8 million kilowatts of power, 5 times its 1962 capacity. In 2005 the utility had a capacity to generate between 43,000 and 54,000 gigawatt-hours of electricity annually, 90% of it hydroelectric, and shared the market with only a handful of private companies producing for primarily industrial needs.