Chirkey Dam

The Chirkey Dam (Chirkeisk GES) is an arch dam on the Sulak River in Dagestan, Russia. The main purpose of the dam is hydroelectric power production, and it supports a 1,000 MW power station. Construction on the dam began in 1964, the first generator was operational by 1974, the last in 1976 while the project was officially completed in 1978. It is the tallest arch dam in Russia.

Design
The dam is a 232.5 m tall and 338 m long (crest) concrete arch dam. It is 6 m wide at its crest, 30 m wide at its base and contains 1275000 m3 of concrete. The dam withholds a 2780000000 m3 reservoir of which 1320000000 m3 is active or "useful" storage. The reservoir has a surface area of 42.4 km2, length of 40 km and maximum width of 5 km. Maximum depth of the reservoir is 200 m and its catchment area is 11290 km2.

The dam's spillway consists of a 509 m long non-pressure tunnel with its intake on the left bank of the dam. The spillway's capacity is 2900 m3/s. The dam's outlet works, spillway and power station have a combined discharge capacity of 3550 m3/s.

The dam's power station contains 4 × 250 MW Francis turbine-generators for a total installed capacity of 1,000 MW. Each generator is supplied with water by a penstock, all four of which intake on the upstream side of the dam's face and run down its surface toward the power station at the dam's base.