Bratsk Reservoir

a reservoir formed by the dam of the Bratsk Hydroelectric Station on the Angara River and situated in the territory of Irkutsk Oblast, RSFSR. The reservoir began to fill in 1961, and the planned high-water mark was reached in 1967. The Bratsk Reservoir effects the long-term regulation of water flow. The reservoir’s area is 5, 470 sq km, its volume is 169.3 cu km, and its average depth is 31 m. The reservoir consists of two main arms, laid out parallel to each other, along the Angara River (547 km long) and along the Oka River (370 km long). A meandering bay about 180 km long has formed along the Iia River, a tributary of the Oka. The width of Bratsk Reservoir on the Angara near Bratsk and the Oka near the village of Shamanovo reaches 20 km. Narrow bays from 1-3 to 15 km long were formed along the valleys of the numerous tributaries. Apart from its basic function for energy production, Bratsk Reservoir is used for water transport, floating timber, fishing, and industrial and communal water supplies. The regulated depths were enlarged as a result of the creation of Bratsk Reservoir, thus making many tributaries navigable. The cities of Bratsk, Svirsk, and Usol’e-Sibirskoe are located on the shores of Bratsk Reservoir.