and generated 13,810 gigawatt-hours of electricity per year on average 2012–16. When it was completed in 1968, the dam was the largest earth-fill structure ever built. The Williston Lake reservoir is the largest lake in British Columbia. A second smaller concrete dam was later built downstream, closer to Hudson's Hope for the Peace Canyon Generating Station which was completed in 1980. Under the terms of the Columbia River Treaty with the US, BC Hydro built a number of dams and hydro-electric generating stations including two large projects at Mica and Revelstoke on the Columbia River. The Keenleyside Dam on the Columbia River north of Castlegar and the Duncan Dam north of Kootenay Lake were also built under the same treaty and are used mainly for water control. Two generators were installed at Keenleyside in 2002, though these are owned and operated by the Columbia Power Corporation (a separate Crown Corporation). Kootenay Canal Generating Station on the Kootenay River between Nelson and Castlegar was completed in 1976. The Seven Mile Dam and Generating Station on the Pend d'Oreille River near Trail were completed in 1979. In the late 1970s and early 1980s BC Hydro investigated the feasibility of geothermal power production at Meager Creek, north of Pemberton. They concluded from their testing that the underground rock wasn't permeable enough to justify large-scale production of electricity. Around the same time, BC Hydro initiated a project to develop a coal-fired thermal generating station at Hat Creek near Cache Creek, but abandoned the effort in 1981 due to strong environmental opposition. In 1989 the Power Smart and Resource Smart programs were initiated by BC Hydro to promote energy conservation as an alternative to the cost of creating new generating facilities. Since 2001, BC Hydro has focused on its conservation and energy efficiency programs, re-investing in its existing facilities, and purchasing clean, renewable energy from Independent Power Producers. According to the "British Columbia Energy Plan", released in 2007, BC Hydro must ensure that clean or renewable electricity generation continues to account for at least 90 percent of total generation. As of 2014, 97 percent of BC Hydro's electricity generation comes from clean or renewable sources and this generation only emits 730,000 tonnes of annually from thermal plants. Organization and financial performance In 1980 the BC Government established the BC Utilities Commission (BCUC) to regulate public energy utilities and to act as an independent, quasi-judicial regulatory