China Quake Shakes Dam Ambitions

DUJIANGYAN, China, Jun 25 (IPS) - China's deadly earthquake appears to have shifted more than just tectonic plates here in picturesque Sichuan province in the country’s south-west.

The May 12 temblor has given a boost to China's green lobby, which has been calling for a review of Beijing's zealous dam-building programme, and may tilt the balance of public opinion in favour of such appeals.

The quake struck an area famous for ancient hydrological works. Sichuan is the homeland of Da Yu, the legendary Chinese emperor who won his right to the throne in 21st century BC by controlling floods. Instead of building dykes as others before him did, Yu dredged river channels to release the torrential waters. He then directed the water to irrigate distant farmlands.

Twenty centuries later, Yu's flood control technique was immortalised in the hydraulic project of Dujiangyan. The ancient system -- operational for the past 2,000 years -- has made the city of the same name a magnet for tourists and has won it recognition as a UNESCO World Heritage Site.

While the city of Dujiangyan was almost entirely destroyed by the magnitude eight earthquake, the old hydraulic system located only 10 km from the epicenter, survived the temblor with little damage. But the same cannot be said about the cluster of 6,000 reservoirs and dams that local experts estimate have been built on the rivers of Sichuan.

"Such a strong earthquake would have an enormous influence on the dams in the whole area," says David Simpson, a U.S. seismologist with the Incorporated Research Institutions for Seismology (IRIS). "You are certain to have concerns if you build many dams in mountainous areas as is the case in Sichuan.”

In the wake of the quake that claimed nearly 70,000 lives, the media has focused more on the frenzy of rescue operations and less on the rush and struggle to assess the damage done to Sichuan's hydropower works.

But as provincial authorities brace for the surge of seasonal floods, the danger of dams bursting and creating a much bigger havoc than the earthquake has, has prompted Chinese experts and activists to raise their voices.

An open letter issued on Jun. 19 by a group of 40 academics and environmentalists warned of more devastation if environmental and geological risks of damaged dams are disregarded. "The quake has highlighted the urgency to make a thorough investigation of damage to the dams, which would embrace another severe test of imminent floods,'' the petition said.

An official survey by the Ministry of Water Resources in May revealed that 2,380 reservoirs and dams all over the country sustained damage from the quake. Some 69 were assessed to be on the verge of collapse -- but experts say this is only the tip of the iceberg.

Modern China did not follow the path of its ancient sages in using rivers' natural flows to control flooding and irrigate land. The late communist chairman Mao Zedong decreed that China's new socialist man must conquer nature. In less than 60 years since the founding of communist China, the country managed to build some 87,000 reservoirs and dams.

More than 20,000 of these have been built to heights that classify them as large dams. Whether in terms of numbers or the scale of dam works, China now is the world's ultimate leader. It is home to the Three Gorges Dam -- a mammoth hydroelectric power project on the Yangtze River -- which in the course of construction displaced more than one million people.

The country's leadership, though, is not stopping here. There are more than 30 large dams on the drawing boards of Chinese engineers awaiting approval and completion, as the country scrambles to feed its energy-starved economy.

Initial official statements after the quake indicated that the government is not wavering from its determination to press on with intensive hydropower development, including in China’s south-west.

"There will be risk assessments of future projects in China's south-west but I don't think the quake would lead to great changes in current plans," Liu Ning, chief engineer with the Ministry of Water Resources told the press soon after the earthquake.

Having harnessed major rivers and tributaries in the country's central and eastern parts, Chinese planners are focusing on developing the abundant water resources of the western and southern provinces. But that water cache comes with a snag - the south-western part of China is also one of the most earthquake-prone zones in the country.

Three major fault lines traverse Sichuan, making it geologically unstable. Nevertheless, many big dams had already been built in the area, such as those on the Min, Dadu, Jinsha and Yalu rivers. The Min river, a tributary of the Yangtze that runs right through the earthquake zone, has not less than 29 reservoirs and dams.

What is more, Zipingpu – the Min river's largest dam -- sits only 5.5 kilometres from the epicentre of the May earthquake. Fan Xiao, a geologist based in Sichuan, in fact believes that the construction of Zipingpu contributed to the severity of the latest earthquake.

"There has never been such a strong earthquake in this area before," Fan says. "Our records show four earthquakes in the past of magnitude above six, but never one stronger than this latest one. Zipingpu is the biggest dam on the Longmenshan fault line and it was filled sometime ago - in the end of 2006. We need to investigate the possibility that the dam was among the triggers of the quake."

The Sichuan Seismological Bureau, which from the very beginning opposed the construction of the dam because of its proximity to the Longmenshan fault, is now investigating the likelihood that the dam could have exacerbated the severity of the tremor.

"We hope the results of the investigation would be made public," says Fan.

Four major earthquakes are acknowledged to have been triggered by dams in their vicinities - in Koyna, India (1967), Kremasta, Greece (1965), in Kariba, Zimbabwe-Zambia (1961) and in Xinfengjiang, China (1962). The Xinfengjiang quake measured 6.1 and damaged the Xinfengjiang power station in Guangdong to such an extent that it had to be closed.

While Zipingpu in Sichuan was built to the highest quake-resistant standards, many other Chinese dams, particularly those designed and constructed during the Great Leap Forward (1958-1961) and in the 1960s, are not. They are often referred to by experts here as "time bombs".

A history of China's half-century of dam building, compiled by academic Pan Jiazheng, estimates there are 30,000 of these poorly built and obsolete structures all over the country.

The May 12 tremor caused the quake-proof Zipingpu Dam to sustain severe cracks and fractures on the sides, but the damage done to other older and less quake-resistant dams is anybody's guess.

The open letter issued by China's green lobby appeals not just for thorough investigation into quake damage but also for risk assessments of all hydropower projects planned for earthquake-prone Sichuan and Yunnan provinces.

A series of 13 dams, many of them taller than the 150 metre-high Zipingpu, are projected to be built on the Nu River, also called the Salween, in proximity to another major fault line near China's border with Burma and Laos. (END/IPSAP/AB/RDR/JS/08)