Fresh concerns over China’s dams

Nearly 100,000 people in the Three Gorges Dam reservoir region may be relocated over the next three to five years due to an increased threat from geological disasters, China National Radio reported on Tuesday. The number of land slides and bank collapses has increased dramatically since the dam on the Yangtze River reached its highest level in 2010, according to local officials. A day later, China Daily reported another 20,000 people in Central China’s Hubei province are slated for relocation due to the risk of landslides in the dam area. The relocation is already underway; schools and hospitals at risk are being evacuated first.

This comes amid growing concerns within China about the effects of building dams in such geologically complicated areas. A study published this month by Probe International found that large dams being built in western China could trigger disaster — earthquakes, even tsunamis — due to their construction in regions of high seismicity.

There is great risk that the dams will be damaged by earthquakes, or that they will induce earthquakes themselves. Of the 130 large dams being constructed in western China, 98.6% are located in moderate to very high seismic hazard zones, and many of them lie directly on geological fault lines. The Zipingpu dam, for example, which is now thought to have triggered the Sichuan earthquake in 2008 that killed an estimated 80,000 people, was built in a moderate seismic zone.

In the interest of public safety, the Probe International report urges the Chinese government to ensure that a thorough and independent regional seismic risk assessment is carried out and publicly disclosed. Many geologists admit that there is little known about these risks because of lack of basic research, as well as secrecy surrounding the dam industry and the country’s seismic records.

Meanwhile, dam construction continues unabated. At the end of March, the Three Gorges Corporation began construction on another controversial hydro projectthe Xiaonanhai Dam, above Chongqing, that will flood the last free-flowing portion of the middle Yangtze River. For years, environmentalists have been fighting this massive project that is set to destroy the region’s last reserve for rare fish. The planned dam also falls within a seismically-active zone that contains at least three fault lines.

But opponents of the dam have not lost all yet. While early stage preparations —building a road and laying power lines and water pipes — have begun: "Construction of the dam itself will begin only after we get final approval," said Zhu Guangming, news department director at Three Gorges Corporation, according to a Reuters report.

With the departure of the recently deposed party sectary Bo Xilai, a major proponent of the project within the Chongqing municipal government, perhaps there remains a chance to persuade hydropower developers, in this case at least, to heed warnings about the potentially disastrous consequences of China’s dams, and put ecology first.