Beijing: China is constructing a secretive 514-kilometre-long irrigation project in its restive Xinjiang region to change the ethnic balance in favour of Han Chinese by moving Uyghurs, Kazakhs and others out of the region.

Jilil Musha, writing in Radio Free Asia (RFA) said that the project aims to open desert areas for development, but experts say it could dilute the Uyghur population.

The project comprises three deeply dug tunnels, the longest of which is the 280-kilometre-long (174-mile-long) Kashuang Tunnel.

Despite the project's size, China's official media has yet to report on the irrigation network as it is being built at a time of well-documented persecution against Uyghur Muslims who live in the area.

However, workers have been hit by strong streams of water, forcing them to flee the site. The problem is having a serious detrimental impact on construction, according to the Tunnel Construction report, said Jilil.

The tunnel project seeks to divert water from the higher reaches of the Irtysh River, the source of which is snow from China's Altay Mountains into the deserts of northern Xinjiang. The precise endpoint is not yet known.

The river is an international waterway that flows through Xinjiang, Kazakhstan and Russia into the Arctic Sea. The river -- the second-largest river in Xinjiang -- is fed by some 11 billion cubic meters (388.5 billion cubic feet) of snow per year, according to the Chinese government.

Sean Roberts, director of the International Development Studies program at George Washington University and the author of the book The War on the Uyghurs: China's Internal Campaign against a Muslim Minority, told RFA in December that the project could help to raise Xinjiang's population of Han Chinese, the country's national majority ethnic group, as a counterweight to Uyghurs.

"We know that the Chinese government is very interested in changing the ethnic balance in the Uyghur region in favour of Han Chinese, and one of the difficulties that have created is that it has required moving Uyghurs, Kazakhs and others out of the region because of the environment [there]," he said.

"It would be impossible just to bring more people into the region, and that's mostly because of the arid nature of the region," Roberts said.

The project also has the potential for changing the demographics of Xinjiang for years to come, he said, said Jilil.

"It could lead to many more Han being able to settle in the region and overwhelm those Uyghurs who remain in the region, so it could speed up the dispossession of Uyghurs and other indigenous peoples of this region [from] their connection to this particular land," Roberts added.

The Chinese government sees the low population of Han Chinese, currently 8 per cent in southern Xinjiang, as a security concern, according to an August 2021 report on Beijing's population optimization strategy in southern Xinjiang by German researcher Adrian Zenz.

The project is not the first time China has attempted to direct water to Xinjiang and relocate a greater number of Chinese migrants to southern Xinjiang.

In an earlier project, Chinese researchers planned to build a 1,000-kilometer tunnel to divert water from the Yarlung Tsangpo River in the Tibetan Plateau to the Tarim Basin.