You probably assume that rivers run to the ocean—and in general, that's true. But not everywhere. Big chunks of the world (the American Southwest, central Australia, about half of the Sahara) are "endorheic basins," meaning that water there just flows inland to some low point, and never flows out. There's a swath of central Asia bigger than the contiguous United States that's endorheic, stretching from Turkey all the way to eastern Mongolia. Every river in this vast area drains into dusty deserts, or lakes like the Caspian and Aral Sea. The Aral Sea has been dwindling for decades, but one part of the lake is now growing again.
It took just 30 years to make a vast sea disappear.
When the Soviet Union diverted the Amu Darya and Syr Darya rivers to irrigate cotton and rice fields in the 1960s, it turned the Aral Sea—once the world's fourth largest lake, roughly the size of West Virginia—into desert. Hulks of rusty fishing boats now dot the dry lake bed between Kazakhstan and Uzbekistan, and fishing villages became ghost towns.
A Small Aral Sea survives.
In 2005, Kazakhstan took drastic measures: they used World Bank funding to build a dam across what was once the lake's largest island: Kokaral Island. Kokaral had become a peninsula and then an isthmus as the water level dropped. But today there's an eight-mile dam, roughly two stories high, running across the narrow gap. And the dam is working. Water levels north of the dam, in what is today called the "North Aral" or "Small Aral" Sea, have risen three meters.
Landlocked fishing docks wait for the water to come back.
As the Small Aral rises, delta and wetland areas are returning to the dry sea bed, and the harsh salinity of the lake is dropping. Fish are starting to come back—first a salt-tolerant species of flounder, then perch, carp and catfish—and so are the fishing communities. The rising lake is now just ten miles away from the old market town of Aralsk, where the walls of an empty harbor have been dry for decades.
The dam has held—but at a cost.
By blocking the Kokaral isthmus to save the North Aral, Kazakhstan has essentially given up on the southern part of the lake, and the Uzbeks down south aren't happy about it. Water that sluices through the dike during the wet season may be enough to bring some fish farms back to what was once the main part of the lake, but that's—quite literally—just a drop in the bucket. 90 percent of the Aral Sea is gone forever.
Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.
