Kazakhstan brought half of a dying sea back to life
The Aral Sea was once the world’s fourth-largest lake. Soviet irrigation drained it into a desert, but a dam built by Kazakhstan in 2005 revived its northern part, and the fish came back.
In 1960 the Aral Sea, on the border of today’s Kazakhstan and Uzbekistan, covered about 68,000 km²: the fourth-largest lake in the world, with busy fishing ports and its own fleet.
Draining a sea
Two great rivers fed it: the Amu Darya and the Syr Darya. From the early 1960s, Soviet planners diverted them into vast irrigation canals to grow cotton, rice and melons in the desert. The rivers stopped reaching the sea.
The Aral shrank year after year. It split into a northern and southern part in 1987, and salinity rose until most native fish died. Ships were left rusting on dry land, kilometres from the water. By 2014 satellite images showed the eastern basin of the South Aral had dried up completely, leaving the Aralkum, a new desert of salty dust.
The comeback
Kazakhstan, which controls the northern part, chose a practical fix. With support from the World Bank, it built the Kokaral dam, completed in August 2005, to keep the Syr Darya’s water in the North Aral instead of letting it drain into the dying south.
The results surprised many people:
- the water level rose from below 30 m to about 42 m by 2008;
- salinity fell from about 30 to 8 grams per litre;
- freshwater fish returned, and commercial fishing came back to towns like Aralsk.
The lesson
The South Aral, mostly in Uzbekistan, is still largely lost, and full restoration of the old sea isn’t realistic. But the North Aral shows that some environmental damage can be partly reversed with focused engineering and the will to do it.
Watch
NASA satellite images, 2000 to 2018. The large southern basins shrink and the eastern one dries out, while the small northern sea (top) keeps its water.
Bring it up
“The Aral Sea is often called a lost cause, but the northern part in Kazakhstan has actually come back, with fish and fishermen again.”
Follow the thread
- RelatedWhen a measure becomes a target Planners chasing cotton output targets ignored the sea the numbers didn’t measure.
- In contrastVenice stands on an upside-down forest Two places defined by water: one drained by engineering, one preserved by it.
- RelatedThe country that gave up the world’s fourth-largest nuclear arsenal Two of the Soviet era’s heaviest environmental legacies in Kazakhstan.
