Chinese dam building on Tsangpo River has India concerned about water diversion impacts.

India has decided to launch a detailed investigation into whether the Brahmaputra River is at serious risk for flash floods due to dams the Chinese are building on the waterway's upper reaches in the country's Tibetan region.

Delhi is worried because China has built one dam on Yarlung Tsangpo, the Chinese name of the Brahmaputra, and has started on two others in what could be a five-dam package.

“We are going to study all aspects of the Brahmaputra to determine the potential risks involved,” Indian Minister V.K. Singh told journalists during a recent visit to Beijing.

Separately, the Indian Ministry of Water Resources recently noted that it has asked the Indian Satellite Research Organization to study both the Ganges and Brahmaputra rivers, which flow from the Himalayas.

By itself, the construction of the dams on the Brahmaputra River, the world’s highest-flowing river, is an engineering challenge.

China’s state-run dam builders, China Huaneng Group and China Gezhouba Corp., are cutting through the mountains to create roads, tunnels and dam walls in extremely inhospitable conditions at heights exceeding 3,200 meters.

One of the dams—the 510-MW Zangmu project, located in the middle reaches of the river—is awaiting completion before year's end. Zangmu, which is 114 kilometers from the Tibetan capital of Lhasa, is 390 m long and has a maximum stipulated height of 116 m.

Two other dams, the 510-MW Gyatsa and 360-MW Zhongda, are under construction. The remaining two, Jiexu and Langzhen, are still on the drawing board.

Although, in the past, Chinese officials have talked about producing 40,000 MW from Tsangpo/Brahmaputra projects, the government has released details of only five dams, having a total installed capacity of about 2,000 MW.

Earlier reports from China have suggested that the Tsangpo/Brahmaputra water will contribute to the massive south-north water-diversion project that China now is implementing.

“The dams on Yarlung Tsangpo will be built only for the purpose of electricity. There is no plan to divert its water to China’s arid regions,” Shaofeng Jia, vice director at the Center of Water Resources Research in the Chinese Academy of Sciences, told ENR.

There are sharp differences of opinion about China’s intentions. Some ask why the country is going to such lengths, building on difficult terrain and risking severe ecological imbalance for the sake of only 2,000 MW of capacity—not very high by Chinese standards and seemingly unnecessary in Tibet, where there is little industrial demand for electricity.

“These five dams are in the first phase of the plan. There are reports of subsequent phases, which are far bigger, but no clarity on the actual size of the projects,” said Joydeep Gupta, South Asia director of Thethirdpole.net, an internet publication dedicated to Asia’s water crisis. “We've had contradictory information about whether one of them will have pondage or not."

Some experts believe that, when fully realized, the project could total 11 dams, which would make it the world's largest dam complex—nearly double the size of the 22,500-MW Three Gorges dam.

To substantiate this claim, these experts refer to the Chinese officials who have speculated that, eventually, river water would be channeled to dry areas of China on the border of Central Asia. “Some people in China have talked about diverting Tsangpo water and taking it as far as Xinjiang in the west. But these are their personal opinions. The government has no such plan,” Jia said.

In truth, the Tsangpo/Brahmaputra program has been marinated in a variety of flavors since the 1960s. The first set of planners were military commanders, who saw the dams as a tool to deal with border problems with India and political troubles in Tibet and divert water to arid regions.

Some scientists and academicians have made proposals the government finds difficult to adopt. One top Chinese Academy of Physics official, quoted in Chinese media, has suggesting the use of nuclear energy to cut a massive pass in the Himalayas to draw in monsoon winds to China’s dry regions.

“This plan was never feasible. There is not sufficient moisture in the air to make it useful," Jia said. "Even a 10-kilometer-wide crater in the Himalayas would not be sufficient to draw monsoon winds flowing all the way from the Indian Ocean."

Environmentalists are up in arms that the project is disturbing the delicate ecological balance of the Tibetan plateau, from which 10 major rivers, including the Yangtze and Mekong, flow to feed nearly a third of Asia.

Fears of flash floods and halts to water flow have resulted in protests from downstream nations, including India, Bangladesh and Bhutan. Indian officials repeatedly have sought assurances from China that it is not building mountaintop reservoirs that could make India vulnerable to floods. Beijing says it is building only run-of-the-river hydroelectricity projects.

“India needs to be very vigilant about Chinese interventions in the [Tsangpo/Brahmaputra]. The run-of-the-river projects are slowly being recognized as a seriously harmful set of interventions,” Ramaswamy R. Iyer, former secretary of water resources in the Indian government, told ENR.  “Adjustment of river flows to the intermittent operation of the turbines creates huge diurnal variations in downstream flows, which are devastating to aquatic life and riparian populations.”

It is clear the project is still in the making. The current focus may be on electricity generation at a limited scale, but observers speculate that Chinese authorities may well expand the project's scale and use to include water diversion and higher levels of power-generation capabilities.

Even today, there are sharp differences within the Chinese government over the issue of diverting water. Officials in the less-developed northern and western regions are demanding higher water flows for industrialization, such as the water-intensive gas industry in the Xinjiang province.

But others contend that, currently, only about a sixth of the flow is being used in China's south-north water-diversion project. Water demand by agriculture and industry is falling, and desalination has become much cheaper than in the past, they add.