Xiang Chuncai, who has lived much of her 84 years on this hillside of orange groves above the Yangtze, recalled waking in fright last year to rattling windows and rumbling noises from the earth. The tremors returned several times in past months, residents of this village in Hubei province said.

"It's all been splitting since the Three Gorges Dam was filled," Xiang said, poking a wide crack snaking up a wall in her earth-brick home. "We don't have the money to move ... I'm scared what will happen if we stay," Xiang added.

Along the 660-km (410-mile) reservoir, residents pointed to erosion, slides and deformed terrain they said have seriously worsened since last year, when the water level was raised a second time.

While authorities have vowed to contain geological aftershocks from the dam, poor farmers worry about being swallowed up by landslides. The resulting tensions threaten to rekindle the bitter clashes that long dogged the project.

"Sometimes the ground rumbles and shakes, dogs bark, babies cry. It frightens us too," said Xiang's neighbour, Su Gongxiang, showing his front door that will no longer shut.

MASTERING NATURE

These days, China stands almost alone among nations in wielding the wealth and will to conjure up vast engineering efforts to alter the flow of rivers and lives of millions.

The Three Gorges Dam is the world's biggest, an engineering feat that seeks to tame the world's third longest river while displacing 1.4 million people.

The 6,300-km (3,910-mile) Yangtze, which rises on the Tibetan plateau, flows through the towering Three Gorges to irrigate, and often flood, much of the country's central and eastern plains.

From 1919 a succession of leaders argued that a dam would end devastating floods and generate power. That dream eluded the revolutionary founder Mao Zedong, whose plans for a dam foundered in political turmoil and poverty.

But in the 1980s, a new generation of Communist Party leaders championed the plan as a trophy of growing economic power.

They faced down opposition from environmental critics and sceptical scientists who in 1992 persuaded an unprecedented third of the usually docile Party-controlled parliament either to oppose the plan or abstain from voting.

Construction began in 1994.

Since the 2,309-metre-long dam was finished in 2003, the reservoir has been filled with water in stages. If all goes to plan, it will reach its maximum capacity of 39.3 billion cubic meters of water by the end of 2008, capping a year of national glory centred on the Beijing Olympics.

"NEVER LIKE THIS BEFORE"

But in Chenjialing this engineering triumph has brought bewilderment and the resigned anger that comes easily to people with little say over their own lives.

Its 1,400 villagers live above what was once a rivulet that could be waded across. These days it is a deep inlet that can moor big coal boats plying the Yangtze.

Everywhere among the fruit groves and potato fields is evidence of a bruised and unsettled landscape.

A hulking old tree has begun to tilt riverward, a nearby earth terrace suddenly subsided, and many houses show cracks and warping, all since last year, villagers said.

"We worry about staying but can't move," said Su Zhonghen, washing clothes in an outdoor stone sink that now skews to one side. "Only families with flooded homes get compensation."

A nearby bank of the Yangtze collapsed last year, tossing several homes into the water, and the county government has put signs around Chenjialing warning of "geological hazards".