Beijing  - China's Three Gorges Dam, due to be completed in November, is getting bigger every day on all fronts.

While officially the government said it has spent 180 billion yuan (26.35 billion dollars) on building the 185-metre dam and a reservoir stretching more than 600 kilometres, local critics and foreign observers said the real figure could be more than twice that amount, and that's just in the construction phase.

A new figure emerged in local media, indicating that nearly 100 billion yuan would have to be spent over the next 10 years to manage the myriad social and environmental problems that have risen alongside the dam's concrete wall.

The financial magazine Caijing and local newspapers reported that 98.9 billion yuan would be needed over the next decade. Of this, 38.2 billion yuan would be spent on environmental protection.

A spokesman with the Yangtze River Water Resources Commission neither confirmed nor denied the figure, which has been submitted as part of a larger post-construction plan to China's State Council.

"The plan is not finished," he told the German Press Agency dpa. "It's still in the early working phase."

"The formal report will come out at the end of the year," the spokesman said. "The State Council has not yet approved it."

A State Council representative confirmed the report was in its drafting phase and refused to give details.

But the estimate confirmed that the environmental and social impact of the dam is not only massive in scale but larger than initially projected.

According to Caijing, since September, when the project authority carried out tests to try to raise the dam's water level to a desired 175 metres, the surrounding region of Chongqing has seen 150 mudslides across 13 counties.

In one recent case, 55 people were evacuated from their homes in Yunyang County after 3.6 million cubic metres of soil became destabilized in November, state media reported. Night traffic on the Yangtze River was suspended for three days, the official Xinhua news agency reported. The ban was no small matter in an area that sees 300 vessels carrying 23,000 passengers every day.

The government has touted a benefits of the high-cost Three Gorges project, whose 26 generators, once operational, are to be able to supply the power needs of more than 18 million households.

But experts said the money to build the project and the resettlement of 1 million people to carry it out have been only part of the costs of the dam.

Fan Xiao, a geologist with the Sichuan Bureau of Geological Exploration of Mineral Resources, told dpa that the chance of geological hazards in the Three Gorges area has increased along with the difference between the high and low water level marks.

In the past, when the water fell to the low level mark before the wet season, it saw a 10-metre drop, but because of September's trials, the most recent drop was almost 30 metres, Fan said.

Now, with more land set to be inundated when the water level is at its highest in the dry season, the chance of landslides could be increased when the water is lowered during the wet season.

Fan said the tests last year also revealed serious design flaws that could enhance geological hazards.

"When the water next to the dam wall reached 172 metres, the water at the end of the reservoir was over 175 metres. Some places which should have been above the water line were inundated, so they immediately stopped the water storage," Fan said.

This is a serious problem for the project authority. If the reservoir can't be filled to 175 metres, power-generating capacity would also not reach what was projected in the initial project design.

But, as engineers search for a solution, landslides aren't the only geological concern weighing on the minds of the dam's critics. Both Chinese and foreign experts have said that the earthquake in Sichuan in May, which killed more than 80,000 people, might have been triggered by the weight of the 156-metre-high Zipingpu Dam.

A longtime critic of the Three Gorges Dam, Dai Qing, said the dam is also in an earthquake zone and that she is worried about the impact of the changing pressure as its water levels fluctuate.

"I'm concerned about earthquakes and other geological disasters - things which cannot be controlled by humans and cannot be stopped," Dai said by telephone.

Dai also questioned why another 100 billion yuan of public money would be spent on the project and called for the national auditing bureau to hold a hearing on how the original funding has been spent.

"I'm one of the people who has paid for this," Dai said. "I have the right to know where the money has gone."(dpa)