Being brackish rather than saline they have high rates of evaporation, prompting a moist summer microclimate, often attracting rain clouds, which has led to the replenishment of the North Aral Sea.

The system now provides close to original flows into the North (Small) Aral Sea, by which dams are being built to divorce the south, accelerating its recovery.

The Amu Darya's turning over to irrigation and the lake mentioned (which sits much lower) denies the South Aral Sea most of its former inflow, provoking the latter's drying up, but enabling central Turkmenistan, among other zones, to have imported sources of river water.

This has gradually filled up the natural cavity of Arnasay lowland to create the largest lake of Central Asia excluding its long western border, the Caspian Sea.

In addition to fauna common in the Kyzyl Kum, there are many kinds of water birds migrating from the Aral Sea that make their homes around the lake.