China admits to big problems from its big dam

MIAOHE, China — The Three Gorges Dam, said to be the world's biggest civil-works project, spans a mile and a half across the Yangtze River. Nearly a year and a half after it was completed, the government still touts the $26 billion dam as a showcase project that limits disastrous seasonal flooding and generates vast amounts of electricity.

But authorities now admit that the dam is generating major problems. It's created a huge — and heavy — reservoir pressing against the mountains along the Yangtze, making them more prone to landslides. The deep reservoir stretches upriver about 370 miles, impeding the natural flushing action of the river and trapping pesticides, fertilizer and raw sewage.

Downriver from the dam, water flows cleaner and faster, adversely affecting aquatic species adapted to sediment in the river.

Authorities are finally letting reports of the dam's problems reach the public in an apparent bid to pre-empt criticism should disaster unfold.

"If no preventive measures are taken, the project could lead to catastrophe," the official Xinhua news agency warned in an unusually blunt report two weeks ago during a forum on the environmental consequences of the project.

The report cited Tan Qiwei, the vice mayor of Chongqing, a sprawling city at the head of the reservoir, as saying that slopes along the Yangtze had collapsed in 91 places and a total of 22 miles of land along the river had caved in.

To make way for the reservoir, authorities relocated about 1.3 million people, moving them away from the rising river and allowing 100 or so towns to submerge slowly under floodwaters rising more than 500 feet. As new landslides loom, more relocations are taking place.

The rising Yangtze has caused other woes, including higher winds in the gorges.

"The dam has brought harm to local people's lives even though it is a great project with lots of benefits for the country," said Han Yong, a 31-year-old farmer.

China's communist leaders ordered work to begin on the Three Gorges dam in 1993, foreseeing the world's largest hydroelectric project. The showcase dam, first envisioned nearly a century ago, towers 600 feet and holds back 20 billion tons of water in the reservoir. When all 26 mammoth turbines are operational, perhaps within two years, the dam may provide 10 percent of China's electrical needs.

Experts said engineers had toiled for decades over the project and knew that the reservoir was so weighty that it might cause earth tremors.

Some landslides have sent walls of water more than 100 feet high crashing across the reservoir to the adjacent shoreline, causing even more damage, Huang Xuebin, the head of the Office to Prevent and Control Geological Disasters in the Three Gorges Reservoir, told the forum last month.

The environmental problems have proved especially nettlesome.

"The quality of the water is much worse than we expected, especially in the tributaries," said Weng Lida, the former chief of the Yangtze River Water Resources Protection Bureau, a government agency, who now works for a regional trade group.

Many tributaries along the Yangtze are experiencing algae and aquatic blooms because the water flows have slowed markedly amid a buildup of pollutants, he said.

"In the reservoir area, the water is quite static. That significantly reduces the cleanup capacity, the purifying capacity. In the harbor areas, there is almost no flow," said Li Lifeng, the chief of the fresh-water program for WWF China, a branch of the global environmental-advocacy group.

The amount of raw sewage pouring into the river has doubled this decade, and huge trails of flotsam commonly entangle its waters.

"There are millions of tons of floating rubbish that cannot head downstream. This matter compresses and sinks to the bottom of the reservoir. Gradually, it will ferment and produce marsh gas," said Wu Dengming, the head of the Green Volunteer League of Chongqing, a nonprofit environmental group.