Ecco cosa è apparso su The Times di qualche giorno fa; si parla della enorme diga delle Tre Gole, una mastodontica opera che ha completamente cambiato (o stravolto) un'area molto molto vasta della Cina. Il risultato è una centrale idroelettrica di proporzioni spaventose, una potenza nominale di 18000 MW. Per intenderci, una normale centrale di fiume o lago (quelle che vediamo noi in montagna sulle Alpi) non supera le decine di MW (se la taglia è importante).
Chinese admit that Three Gorges Dam is an ecological disaster
Now those same officials who oversaw construction of the £13 billion project have issued a rare public warning that surrounding areas are paying a heavy, and potentially calamitous, environmental price. Hundreds of thousands of people may have to be moved, in addition to the 1.3 million who have already been displaced.
A report issued by the official Xinhua news agency, the mouthpiece for the Government, said: “There exist many ecological and environmental problems concerning the Three Gorges Dam. If no preventive measures are taken, the project could lead to catastrophe.”
Officials and experts at a government forum listed a litany of threats to the environment, such as conflicts over land shortages, ecological deterioration as a result of irrational development and, especially, erosion and landslides on steep hills around the dam. Other authorities have already quietly cited anxieties about algae bloom downstream from the huge structure and a deterioration in aquatic life.
The project was hailed by proponents in the Government as an achievement to rival the Great Wall. But in a rare admission of official failure, Wang Xiaofeng, the director of the administrative office in charge of building the dam, said: “We absolutely cannot relax our guard against ecological and environmental security problems sparked by the Three Gorges project. We cannot win passing economic prosperity at the cost of the environment.” He even revealed that Wen Jiabao, the Prime Minister, had openly aired the problems surrounding the dam during a cabinet meeting this year.
The timing is significant, coming only two weeks before the Communist Party is to hold a five-yearly congress at which it will cement policy and anoint a new generation of leaders. One political analyst said: “It’s a way for President Hu Jintao to distance himself further. He deliberately stayed away from the official completion ceremonies a year ago and this underlines that his administration does not want to be associated with the Three Gorges.”
The project to create a dam producing more than 18,000 megawatts of power — 20 times more than the Hoover Dam in America — has long been dogged by controversy. In 1989, one vice-premier ordered a five-year moratorium on the debate, but that was ignored when conservatives gained power after the Tiananmen Square crackdown. In 1992 the virtually toothless National People’s Congress, or parliament, approved the dam, although a third of deputies voted “no” or abstained in the biggest such vote in the history of Communist Party rule in China.
Dai Qing, an environmental activist, has been the most vocal of the dam’s opponents. She said: “We have never stopped talking about the problems but our voice was too weak. The system does not listen to the voices of civic activists or dissidents. But now, at last, they are starting to hear.” One of the most worrying consequences for Chinese officials has been the dramatic increase in landslides around the dam. Studies by geologists have shown that the seeping of water over the huge area of the reservoir and the huge pressure changes are weakening the banks.
One official said that the lives of residents around the reservoir were under threat from such geological disasters. Another said that the shore of the reservoir had collapsed in 91 places and a total of 36km (22 miles) had already caved in.
Landslides have produced waves as high as 50 metres that crashed into the shoreline, creating even more damage. In July a mountain along a tributary collapsed, dragging 13 farmers to their deaths and drowning 11 fishermen in a two-storey-high wave.
Ms Dai told The Times: “The Government knows it has made a mistake. Now they are afraid that the environmental catastrophe that they cannot prevent will spark civil unrest. So they want to go public before the troubles start.”