[5] 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 in order to irrigate cotton and food crops in Kazakhstan and Uzbekistan.

Once the water level falls below the connecting channel (elevation 29 m), the salinities can be expected to diverge further.

Under current conditions, the eastern basin may receive water from the Amu Darya in wet years, fluctuating in salinity and flooding an area of up to 4500 km2 in salt water to a depth of about one meter, which would preclude any economic activity in the area, while the western basin becomes increasingly saline.

[6] Water diversion from the Amu Darya directly to the deeper western basin could lower its salinity enough to allow resumption of local fisheries, while allowing the eastern basin to desiccate almost entirely and avoiding the problems of flooding.

It is expected to alternate between complete desiccation in the summers and the occasional flood from the Amu Darya or spillover from the dam holding back the North Aral Sea, though a second dike, begun in 2010, may reduce the incidence of the latter.