Lakes, reservoirs and groundwater

Lakes are few in Central Asia; the largest are the Aral, Issyk-Kul, Balkhash and Karakul, which are of tectonic origin. Issyk-Kul (Kyrgyzstan) is very deep, covers about 6200 km² and does not freeze in winter because its water is slightly saline. The western part of Lake Balkhash is fresh and the eastern part is salty. Many small mountain lakes were formed when a river channel was blocked; Sarichelek is one of them. Until 1960 the Aral Sea was one of the largest lakes in the world (about 68 000 km²), but because much of the Amudarya and Syrdarya water was taken for irrigation, inflow fell sharply. As a result the sea has largely dried up: the eastern basin of its southern part dried completely in the 2010s and the Aralkum desert appeared in its place, while the Small Aral in Kazakhstan was partly restored thanks to the Kokaral Dam of 2005. Salt and dust from the exposed bed are blown by wind and harm health and farming; now saxaul and other plants are being planted there. For irrigation, hydropower and regulating water, reservoirs such as Kayrakkum, Chardara, Tokhtogul, Charvak and Tuyamuyun have been built on rivers.