river in southeast central Russia. It is the outlet for Lake Baikal and a major tributary of the Yenisey River, which it joins near Yeniseysk. The river flows for 1,105 miles (1,779 km) across the southern part of the Central Siberian Plateau and drains over 400,000 square miles (1,040,000 square km). It cuts across basalt flows, which cause many rapids and provide great potential for the generation of hydroelectric power. Dams and power stations were completed at Irkutsk (1956) and Bratsk (1964), the latter creating a reservoir of 2,125 square miles (5,504 square km); a third station at Ust-Ilimsk was completed in 1977; and another hydroelectric station and dam at Boguchany, downstream from Ust-Ilimsk, were under construction in the late 20th century. Power is used in the Irkutsk-Cheremkhovo industrial area along the river.