The Sulak is a river in Dagestan

Dagestan

The Republic of Dagestan is a federal subject of Russia, located in the North Caucasus region. Its capital and the largest city is Makhachkala, located at the center of Dagestan on the Caspian Sea...

, Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It starts at the confluence of the Avar Koisu and the Andi Koisu rivers. It comes down the Main Sulak Canyon (700-1500 m deep) and the Akhetl and Chirkei gorges and the Minor Sulak Canyon. Then it comes to the wide valley and forms a delta

River delta

A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

, flowing into the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

.

Sulak's water is used as the water supply of Makhachkala

Makhachkala

-Twin towns/sister cities:Makhachkala is twinned with: Sfax, Tunisia Siping, China Spokane, United States Vladikavkaz, Russia Yalova, Turkey Ndola, Zambia-See also:*...

 and Kaspiysk

Kaspiysk

Kaspiysk , until 1947 known as Dvigatelstroy , is a city in the Republic of Dagestan, Russia, located on the Caspian Sea, southeast of Makhachkala. Population: 43,000 ....

 and to generate electricity in a series of hydroelectric power

Hydroelectricity

Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

 stations, at Miatl, Chiryurt, Chirkei

Chirkey Dam

The Chirkey Dam 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...

 and Bavtugai with a total power 1345.6 MW.