Once the tunnel is approved, it will most likely affect the water flow in the Brahmaputra, that could cause draughts. The plan involves diverting water from Sangri county in Tibet to the Taklamakan desert in Xinjiang. In 2010, China had assured India that it had no plans of building dams in Tibet after New Delhi expressed concerns.
China’s top leadership is considering digging a 1,000-km long tunnel, which if completed would be the world’s longest by a huge margin, to divert the waters of the Brahmaputra from Tibet to its dry Xinjiang region.
The Brahmaputra, called the Yarlung Tsangpo in China, originates in Tibet and flows downstream into India’s northeast and sustains millions of people in its basin flowing into Bangladesh before meeting the Bay of Bengal.
Once the tunnel is approved, it will most likely affect the water flow in the Brahmaputra, that could cause draughts which have so far been uncommon in the river basin, as it’s more prone to floods. Observers said storing vast quantities of water prior to dispatch through the tunnels could also increase the risks of flooding downstream.
The plan involves diverting water from Sangri county in Tibet to the Taklamakan desert in Xinjiang. The South China Morning Post in Hong Kong quoted Chinese engineers as saying that the plan has been submitted to higher authorities for approval by March 2018.
“An important factor holding up approval for the gigantic project is the environmental risks involved in cutting through fragile mountains,” an engineer attached to Chinese government said. Another factor could be the high cost involved.
One Chinese expert, Wang Wei, who works for the State Key Laboratory of Hydraulics and Mountain River Engineering at Sichuan University, estimated that the cost would be one billion Yuan (approximately $ 150 million) per km of the tunnel. This would mean an overall cost of around $150 billion.
China had assured India in 2010 that it had no plans of building upstream dams in Zangmu in Tibet after New Delhi expressed concerns about the same. Beijing had said that it was merely building run-of-the-river dam for hydroelectricity and that there was no need for it to hold vast quantities of water that could endanger downstream areas in India.
The water diversion project, if approved, would mean China’s going back on its assurances.
Observers here said China might weigh in in favour of the project if it serves its strategic interests+ , which include pressuring India. It has already committed $60 billion for the China-Pakistan Economic Corridor+ , which, experts say, has more strategic value than economic worth for Beijing.
Another researcher, Zhang Chuanqing, said Beijing “would definitely go ahead with the project one day”.
“In five to 10 years, the technology will be ready and the cost affordable, and the temptation of the benefits will be difficult to resist,” said Zhang Chuanqing, a researcher at the Chinese Academy of Sciences’ Institute of Rock and Soil Mechanics in Wuhan, who is involved in developing another plan for a 600-km long tunnel in Yunnan.