region The Ili is the main watercourse of the Balkhash-Alakol Basin. The region of Kazakhstan partially drained by the Ili and its tributaries is known in Kazakh as Zhetysu ('Seven Rivers'). In Russian it is known as Semirechye (meaning the same). The Kapshagay Hydroelectric Power Plant was constructed between 1965 and 1970 near Kapchagay in the middle reaches of the Ili River. This currently comprises the Kapchagay Reservoir, an artificial long lake north of Almaty. The Tamgaly-Tas, a protected site that comprises rock drawings, is located downstream along the Ili River. The name Tamgaly in Kazakh means "painted" or "marked place" (Tas means "stone"). Ili Delta The Ili River flows into the southeastern edge of Lake Balkhash, where it forms a large delta of about . The delta is situated between the Saryesik-Atyrau Desert and the Taukum Desert. An area of 9,766 km2 (3,771 sq mi) within the delta has been designated as a Ramsar Site. This site has 427 species of plants and 345 species of animals, including important populations of rare species (Dalmatian pelican, goitered gazelle, marbled polecat, white-headed duck, red-breasted goose, ship sturgeon, and others). The delta has also become popular amongst anglers for its wels catfish, which can grow up to over . The Ili river ranks third in Kazakhstan after the Irtysh river and the Ural river in terms of water content. The Government of Kazakhstan plans to join the three sanctuaries Balkash, Karoy and Kukan (situated in the delta) into one National Park. Until 1948, the delta was a refuge of the extinct Caspian tiger. An introduction of the Siberian tiger to the delta has been proposed on account that it is a genetically close relative of the Caspian tiger. A large population of wild boar, the main prey base of the Caspian tiger, can be still found in the delta. There is also a small population of roe deer. In the drier steppes to the south of the delta live saiga antelopes and goitered gazelles. Reintroduction of the Bactrian deer, another prey of the Caspian tiger, is currently under consideration. Another potential prey species considered to be reintroduced is the Asiatic wild ass. Historical connections The Ili River treaty of 638 AD formalized the division of the Western Turkic Kaganate (552–638 AD) into the Nushibi and the Dulu. It also established the Ili River as the border between the two states. In the