The plan to build the hydroelectric plant was approved in September 1954 and later that year the first workers and machines arrived at Bratsk. On December 21, 1954 preparation works were initiated by the Nizhneangargasstroy department (), later renamed to Bratskgasstroy (). Concurrently, the city of Bratsk was founded. On December 12, 1955 Bratsk was officially converted from a workers settlement into a city by the decree of the Presidium of the Supreme Soviet of the RSFSR.
