An engineered resurrection
Once the fourth-largest lake on Earth, the Aral Sea was nearly erased from the map in one of the most severe human-caused environmental disasters. Beginning in the 1960s, Soviet agricultural projects diverted the two rivers that fed the sea, the Amu Darya and the Syr Darya, to irrigate immense cotton and rice fields. The consequences were swift. By the 2000s, the Aral Sea had lost over 90% of its water volume, splitting into separate lakes. Its salinity soared from 10 grams per liter to over 30, killing off almost all native fish species and devastating the regional fishing industry, which employed tens of thousands. The exposed seabed formed a new, 40,000-square-kilometer toxic desert called the Aralkum, unleashing dust storms that carried salt and pesticides across Central Asia.
In a direct effort to reverse a portion of this damage, the government of Kazakhstan and the World Bank funded the Syr Darya Control and Northern Aral Sea Project. The project is the Kokaral Dam, a 13-kilometer-long dike completed in August 2005. The dam was built to separate the smaller North Aral Sea from the rapidly evaporating South Aral Sea. This partition allows the full flow of the Syr Darya river to be contained within the northern basin, preventing it from being lost to the southern desert.
A measurable recovery
The results of the Kokaral Dam appeared faster than scientists predicted. Within seven months of its completion, the water level in the North Aral Sea rose by 3.3 meters. By 2008, the water level had risen 12 meters from its 2003 low, reaching a viable depth of 42 meters. The total water volume increased by over 40%, and its surface area expanded by 870 square kilometers.
This influx of fresh water from the Syr Darya caused a dramatic ecological shift. Salinity plummeted from dangerously high levels to around 8-10 grams per liter, close to its natural state before the 1960s. The reduced salt content allowed freshwater fish to return. While only the hardy flounder could survive before the dam, species like bream, roach, and pike-perch have since repopulated the waters. The annual fish catch surged from just 695 metric tons in 2005 to over 7,000 tons by 2016 and 8,000 tons by 2025. This revival has stimulated the local economy, with fish processing plants reopening in the former port city of Aralsk. The sea, which had receded nearly 100 kilometers from Aralsk, is now within 12 kilometers of the city.