In 2002, China began building the South-to-North Water Diversion Project to carry Yangtze water north; it now reportedly serves 185 million people, but displaced at least 330,000

Imagine moving enough water each year to fill roughly 4 million Olympic swimming pools, then pushing it hundreds of miles across mountains, rivers, and cities just so a family in Beijing can turn on the tap. That is essentially what China has been doing for over two decades. According to research published in Scientific Reports, a journal from the publishers of Nature, northern China's population of roughly 150 million people has been draining its groundwater for so long that wells kept sinking deeper and the ground itself began to subside in places. So the government decided to reroute water from an entirely different river basin hundreds of miles away.

For U.S. readers, think of California’s aqueduct system on a much larger scale.

The scale is almost unreal
The project, officially called the South-to-North Water Diversion Project, links three routes stretching a combined 4,350 kilometers, or about 2,700 miles. The eastern route broke ground first, in December 2002, followed by the central route, which began construction in December 2003. Together, they were designed to pull water from the Yangtze River basin in the south, where rain is abundant, and carry it north to thirsty cities like Beijing and Tianjin.


The central route alone stretches more than 1,400 kilometers from the Danjiangkou Reservoir to Beijing. The same Scientific Reports study titled ‘Energy Reduction Effect of the South-to-North Water Diversion Project in China’ notes that most of that water flows by gravity rather than pumps, thanks to a roughly 100-meter elevation drop along the route. That's smart engineering. Water flows downhill for free, which means less electricity moving it.

Why 185 million people now depend on it
China’s State Council, the country’s top government body, said in a statement that by late 2024, the network has directly benefited more than 185 million people. That’s more people than the entire population of Russia drawing water from one single piece of infrastructure.

The same statement said that roughly 70 to 80 percent of the water used in the urban core of Beijing now comes from this system, after a 15-day journey from the Danjiangkou Reservoir. The annual volume of water transferred through the project has also grown sharply, from just over 2 billion cubic meters when it launched to about 10 billion cubic meters today, according to China's State Council. In its first decade of operation, from 2014 to 2024, the project transferred more than 76.7 billion cubic meters of water in total, according to a report from China's State Council Information Office.

There is a quieter benefit too. The Scientific Reports study noted that the North China Plain’s roughly 150 million people had already pushed groundwater over-extraction past 150 billion cubic meters, creating serious hydrological and geological problems. Based on the government’s reduction plan, the transferred water successfully met its milestone of replacing 2.97 billion cubic meters of groundwater by 2020, saving 931 million kWh. By 2030, replacing 6.44 billion cubic meters of groundwater (about 27% of total withdrawals) is projected to offset energy needs by an amount equivalent to roughly 7% of Beijing's thermal power output.

The human cost nobody talks about
The construction of the central route required the Danjiangkou Dam to be raised and its reservoir enlarged, flooding land that hundreds of thousands called home. A Wilson Centre report says at least 330,000 people were displaced: some 180,000 from Hubei province and 150,000 from Henan province. Many were farmers who tilled that land for generations.

The resettlement wasn't smooth. The same report notes that some relocated families have complained about weak government support and low-quality replacement housing. The issue will sound familiar to Americans who have seen disputes over eminent domain for highways or pipelines. Here, the scale is much larger.

What this means beyond China
For American readers, this project is worth watching for a couple of reasons. First, it's a preview of how far governments will go under serious water stress, and the American West already knows something about that, given its own long-running water disputes and its own aqueducts moving water hundreds of miles.

Second, it raises a difficult question: how do you weigh the water needs of 185 million people against the rights of 330,000 who were displaced? Infrastructure at this scale often creates winners and losers, and the losers may receive less attention.

The project isn't finished, either. A proposed third route, meant to draw water from high on the Tibetan Plateau, remains in the planning stage, with officials citing major engineering challenges. China's thirst for water, it seems, is far from solved.