North Aral Sea levels further were due to begin in 2010. The Aral Sea began shrinking in the 1960s, when the Soviet Union decided that the two rivers feeding it, the Amu Darya and the Syr Darya, would be diverted to irrigate cotton and food crops in Kazakhstan and Uzbekistan. In 1986, due to an accelerated loss of water, the Aral Sea split into northern and southern parts; the southern part is the current South Aral Sea. There is now an ongoing effort in Kazakhstan to save and replenish the North Aral Sea. As part of this effort, a dam project was completed
Geography of Kazakhstan and Tien Shan ranges are covered with snow, year-round, and their runoff is the source for most of Kazakhstan's freshwater rivers, streams, and lakes. Except for the Tobol, Ishim, and Irtysh rivers (the Kazakh names for which are, respectively, Tobyl, Esil, and Ertis), portions of which flow through Kazakhstan, all of Kazakhstan's rivers and streams are part of landlocked systems. They either flow into isolated bodies of water such as the Caspian Sea or simply disappear into the steppes and deserts of central and southern Kazakhstan. Many rivers, streams, and lakes are seasonal, evaporating in summer. The three largest bodies