In July 2015, ContourGlobal acquired the Vorotan Complex of Hydroelectric Power Stations - a complex of three hydroelectric power stations with an overall capacity of 404.2 MW and an average annual power generation of 1.15 billion kWh. The Vorotan Cascade is among the main power generation complexes in Armenia, providing both peak and base load generation, and performing grid stabilization services. The complex is located in the eastern part of Syunik region of the Republic of Armenia, some 240 km to the South-East of Yerevan. The Cascade has a total head of 1,223 m. The design of the Vorotan CHPS began in 1954, construction started in 1961. In 1970 the first power station, Tatev HPP, was put into operation, followed by Shamb HPP in 1979 and Spandaryan HPP in 1989.
The Vorotan Cascade, or the ContourGlobal Hydro Cascade as it was indeed renamed after the acquisition, is located on the Vorotan River. It is comprised of four reservoirs and one Daily Regulation Pond. The Spandaryan Reservoir is the upper reservoir of the cascade. Highest water level is at 2,063 m a.s.l.; minimum water level is 2,030 m. The water is directed through an 8.1 km long pressure tunnel and a 2.17 km long penstock to Spandaryan HPP. The discharge from Spandaryan HPP and water from Vorotan River is retained by Angeghakot dam forming the Angeghakot Reservoir. Highest water level is at 1,677.4 m a.s.l.; minimum water level is 1,664.5 m. Water flows from this reservoir via a 10.5 km long gravity fed tunnel to the Tolors Reservoir, which is also fed by the Sisian and Ayri Rivers. Highest water level is at 1,651.5 m a.s.l.; minimum water level is 1,625.5 m. From the Tolors Reservoir, the water is supplied to the Shamb HPP via a 6.9 km long pressure tunnel and a penstock of 1.26 km in length. Below the Shamb HPP is the Shamb Reservoir (also named Tatev Reservoir) which is also fed by water from Laradzor River. Highest water level is at 1,335.4 m a.s.l.; minimum water level is 1,333.8 m. From this reservoir water flows through an 18.4 km long gravity fed tunnel to the Daily Regulation Pond of the Tatev HPP, from where the water is directed to Tatev HPP via a 1,900 m long pressure penstock.