The Great Soviet Transformation
In the mid-20th century, Soviet planners targeted the arid Karshi Steppe for a massive agricultural transformation. The goal was to create a new, vast region for cultivating cotton, called "white gold," and other crops. This ambition required a colossal amount of water in a region defined by its scarcity. The initial plan focused on diverting water from the Amu Darya, one of Central Asia's two major rivers. This led to the construction of the Karshi Main Canal, a project of immense scale that began in the 1960s and became operational in 1973.
The engineering was audacious. Because the Karshi Steppe sits at a higher elevation than the river, water had to be lifted vertically. The project involved a series of six powerful pumping stations, known as the Karshi Cascade, to raise the river water a total of 132 meters over a distance of 80 kilometers. This system was designed to move up to 200 cubic meters of water per second, feeding a network of canals that would irrigate over 336,000 hectares of desert land. However, even the mighty Amu Darya could not satisfy the project's thirst. Planners turned to a hidden resource: the vast freshwater aquifer lying beneath the steppe.
An Invisible Drought
The Karshi aquifer is a massive subterranean reservoir of groundwater. Extensive exploitation of this resource began as the Soviet irrigation project expanded. This groundwater became essential for sustaining the cotton monoculture, especially during periods of drought or when river flow was low. The relentless pumping for agriculture has had severe, long-term consequences.
Groundwater levels in the Kashkadarya region have dropped significantly, by as much as 10 to 15 meters in some areas. This depletion is caused by a falling water table. Over-extraction leads to land subsidence and increases the salinity of the remaining groundwater, as dissolved salts become more concentrated. The intensive irrigation, combined with the arid climate, also causes severe soil salinization, which degrades the agricultural land the project was meant to create. This process is a slow environmental problem, like the more famous catastrophe of the Aral Sea, which shrank dramatically due to the same large-scale water diversions from the Amu Darya and Syr Darya rivers. The pursuit of cotton has altered the region's hydrology, both above and below ground.