Sevan Hrazdan Irrigation-Energy Complex consists of a cascade of 7 hydroelectric power plants and 17 canals irrigating the Ararat Valley. The construction of the Cascade to utilize the energy potential of the water released from Lake Sevan for the irrigation of the Ararat Valley started in 1930 with the construction of the Kanaker HPP, the first hydraulic unit of which was put into operation in 1936. The construction lasted for 32 years, ending with the launch of the Yerevan-1 HPP. The Cascade hydropower plants use the waters of Sevan lake and tributaries of the Hrazdan River.

The Sevan-Hrazdan Cascade is the largest in Armenia with a total installed capacity of 561.4 MW. With this capacity, the annual production of electricity in 1957-1963 exceeded 2,000 GWh per year, and in 1993, during the energy crisis in Armenia, totalled to about 2,800 GWh. The energy of the Sevan Hrazdan Cascade satisfied about 90% of the Republic's demand by the end of 1950. Since 1978, the flow of water from Sevan lake for energy generation purposes had stopped to prevent further decrease of the level of the lake. Later, with the operation of the Arpa-Sevan tunnel in 1981, the level of Lake Seana began to rise, but since then the Sevan-Hrazdan Cascade derivation system operates with the priority of irrigation for agricultural needs.

The two HPPs of Sevan-Hrazdan Cascade, Sevan HPP and Hrazdan HPP, operate only with the energy of water released from Sevan lake during the irrigation seasons. The rest of the HPPs operate throughout the year, except for the smallest station, Yerevan-3 HPP, which operates during the non-irrigation seasons. The three HPPs of the Cascade: Kanaker HPP, Yerevan-1 and Yerevan-3 HPPs are located in Yerevan, the rest are located along the Hrazdan River between the Sevan lake and Yerevan.

The Cascade derivation system is 65.5 km long, of which 30.7 km are concrete open channels and 34.8 km are tunnels. Argel HPP, the third stage of the cascade, is the largest in Armenia with its installed capacity of 224 MW.

Sevan HPP is the only underground HPP in Armenia, and Arzni HPP is the only rock-cut HPP.

The Sevan-Hrazdan Cascade is essential for the whole energy system of Armenia. Given the age of the cascade equipment and the lack of large-scale full repairs, the power plants of the Cascade need thorough rehabilitation. The Tashir group of companies ahs set ambitious goals to undertake this task with the partnership of large international organizations.