Sevan Hydroelectric System

(also called the Sevan-Razdan System), a group of hydroelectric power plants located on the Razdan River, which flows out of Lake Sevan, Armenian SSR. The system consists of six power plants with a total rated power in excess of 556 megawatts (MW) and an average production of 2.3 billion kilowatt-hr per year. The individual power plants are Sevan (34.2 MW), Atarbekian (81.6 MW), Giumush (224 MW), Arzni (70.6 MW), Kanaker (102 MW), and Yerevan (44 MW).

Construction of the system was begun in 1930 and completed in 1962, when the Yerevan Hydroelectric Power Plant began operating at full rated power. The power plants in the system use artificial releases of water from Lake Sevan and the natural runoff of the Razdan River. The level of the river at its influx into the Araks River is 100 m lower than the level of Lake Sevan. Lake Sevan functions as a long-term regulator for the system. Three reservoirs and two basins designed for daily regulation make it possible to operate the power plants on independent schedules. Electric power generated by the system is supplied to the integrated power grid of the Armenian SSR, which is a part of the integrated Transcaucasian power grid. The power is used by industries in the Armenian SSR, as well as for irrigation of more than 100,000 hectares of land in the Ararat Valley.