It was formed as a result of an emergency measure of flood control to prevent the breaking of Chardara irrigation dam, and in order to prevent damage downstream of the Syr Darya in the territory of Kazakhstan in 1969 (21.0 km’). The System includes three brackish water lakes (Aydar-Kul, Arnasay and Tuzkan). It is one of the latgcst reservoirs in Uzbekistan, covering about 3,500 km2, with an average depth of 8-10 meters.