China Plays Down Dam Failure Concerns

Originally published in the Financial Times

Last updated: May 16 2008 17:17

If Engineer Yue was worried about lingering just downstream of the dam that has been the focus of fears of catastrophic infrastructure failure caused by China's earthquake, he was certainly not showing it.

Despite the large cracks clearly visible on the 156m-tall Zipingpu dam's façade and reports that it might be unsound, Mr Yue said on Friday he was confident it had safely survived the 7.9 magnitude tremor that rocked the area on ­Monday.

"The managers... are all in their offices," said Mr Yue, pointing at an administration building on the far side of the Min River just below the dam. "If it was going to burst they wouldn't be there, would they?"

The sangfroid of Mr Yue, who helped build the Zipingpu reservoir but was ­on Friday working on the nearby road for his construction company, Sichuan Chengyu, came as experts and officials played down concerns about the possibility for dam failure in the quake-hit area.

The hundreds of reservoirs in the rain-soaked hills of south-western Sichuan province have been at the centre of worries about the earthquake's impact on bridges, roads, nuclear installations and other infrastructure.

"In the past the ministry of water resources has itself said that even without an earthquake, there are problems with about one quarter of our nation's reservoirs," said Zhang Boting, deputy secretary of the China Society for Hydropower Engineering. "After an earthquake those problems will be increased."

However, Mr Zhang said that there appeared to be little immediate risk of a dam bursting in the region. No Chinese concrete dam has ever collapsed as the direct result of an earthquake.

Government departments also played down concerns. An official at state-owned Huaneng Power - which had earlier been quoted as saying that two up-stream dams in the area could collapse "at any time" - said on Friday that one had indeed been damaged but "the problem is not big".

The situation of some dams and reservoirs in the area remained unclear, however. The safety of surviving roads and bridges in the area will also take time to confirm - but they must still be used in the meantime.

The quality of much Chinese infrastructure remains open to question amid an unparalleled national building boom; while the nation boasts rich engineering expertise, corruption is widespread and construction standards often loosely applied.

The government has been tight-lipped about the tremor's effect on nuclear reactors and other facilities in Sichuan, home to the country's main atomic weapons research and plutonium production bases.

Hydrologists also warn that even without a catastrophic dam failure, Sichuan's rivers could remain a source of real risk. Barrier lakes caused by landslides can hold back rivers and then burst with devastating effect, a danger officials are trying to minimise by monitoring their growth with aerial and satellite imagery.

"I'm still very worried," said Fan Xiao, a hydropower expert with the Sichuan Bureau of Geology.

Even if all the region's large dams survived, the quake should still be taken as a lesson that China needs to think more carefully about undertaking such works in seismically active areas, Prof Fan said.

"If you only consider the potential for electricity generation, then in the end you may have to pay a very great price," he said.

The five-year-old Zipingpu dam, designed to hold more than 1bn cubic metres of water, was on Friday surrounded by a thunderous mist as managers sought to ease the pressure on it by releasing water.

Downstream in the town of Dujiangyan, Song Shufen waved aside suggestions that such an imposing edifice might fail. "Premier Wen [Jiabao] said the dams need to be checked - but our country has very good dams, so I'm not scared," she said.

ANCIENT WONDER

About 50km from the quake-damaged Zipingpu dam lies the Dujiangyan water diversion and irrigation system, a marvel of the ancient world begun in about 250BC.

State media reports say that although a Dujiangyan dyke suffered cracks in the earthquake, the safety of the world's oldest operating irrigation system remains uncompromised.

The system diverts part of the Min river into artificial channels that still supply the city of Chengdu, a feat testifying to the organisational and hydro-engineering capabilities of ancient Chinese states.

Some scholars argue that the organisation required for such water projects laid the ground for the development of a distinctively Chinese form of government, combining autocratic rule with maintenance of a powerful and educated bureaucracy.

But while projects such as Zipingpu and the huge Three Gorges Dam on the Yangtze river remain contentious, China's ability to create enduring monuments is clear.