BEIJING -- The idea is so colossal and so alluring that, more than 30 years ago, it inspired Mao Tse-tung to poetry.
"The mountain goddess, if she is still there, will marvel at a world so changed," the Great Helmsman rhapsodized.
The idea is to erect a dam across the mighty Yangtze River -- a 610-foot-high and 7,100-foot-long dam that would be the world's most powerful in terms of producing hydroelectricity.
And that is only the beginning of the project's superlatives.
The massive dam would take an estimated 18 years to build, cost at least $11 billion; force resettlement of more than 1 million people, create a lake 367 miles long and 575 feet deep, forever change the landscape of central China and, critics claim, set up an environmental disaster of unimaginable proportions.
Fiercely debated since first proposed in the 1920s, the project currently has a very high-placed proponent in Premier Li Peng, a Soviet- trained hydroelectric engineer who has long been disposed toward huge power projects.
And it now appears to have drawn broad enough political support here to overcome opposition within some elements of China's bureaucracy and from the country's nascent environmental movement.
The latest strong signal that China finally plans to begin constructing the dam east of the city of Chongqing near the border of Si chuan and Hubei provinces was the public announcement late last month that it now has the backing of the chairman of the nation's legislature.
"It is necessary to launch the project soon for the sake of the long-term stability of the national economy as a whole and the safety of the lower and middle reaches of the Yangtze," said Wan Li, head of the National People's Congress, a body invariably in step with the thinking of China's leadership.
Mr. Wan said that the project -- dubbed the Three Gorges Dam after the name of the scenic stretch of the Yangtze that it would destroy -- should become part of China's 10-year development plan for the period 1991-2001.
In late July, an inspection commission appointed by the State Council, China's equivalent of an executive-branch Cabinet, voted unanimously in favor of building the dam, according to Hong Kong newspaper reports at that time.
What appears to have tipped the political debate in favor of the project is the flooding that devastated much of eastern China this summer, killing about 2,300 people and affecting the homes, fields and industries of more than 220 million others.
The flooding was most severe in densely populated, relatively prosperous Anhui and Jiangsu provinces, through which the lower reaches of the Yangtze flow.
The world's fifth-longest river, the Yangtze so regularly floods that more than 300,000 people have been killed by its overflowing waters in the last 60 years.
Supporters of the Three Gorges Dam maintain that it not only will control the Yangtze but that it is the only way to provide badly needed power to develop China's still-impoverished interior.
The dam is planned to generate 17.6 million kilowatts, 40 percent more than the world's current most powerful dam, the new Itaipu dam in Brazil.
But critics of the project, who have been largely silenced by the broad political crackdown following the 1989 Tiananmen Square protests, have claimed that the dam will create a vast ecological mess that would wipe out the rare Yangtze River white dolphin; will obliterate the 125-mile-long Three Gorges area, praised for centuries as one of China's scenic wonders; and will even cause earthquakes.
The dam's critics also claim that its cost could easily run more than $20 billion, or a third of China's annual central government budget; that new farmland is unavailable for those who would be displaced; and that, in the event of war, it would provide a vulnerable target.
The threat of bombing the dam "could be used for blackmail by the outside enemy," Qian Weicheng, a leading Chinese physicist concluded in April in an imaginative assessment of the high-tech weaponry displayed earlier this year during the Persian Gulf war.
Such frightful environmental and military scenarios, however, have not deterred the Three Gorges' backers, who already have begun to shape the marvel about which Mao Tse-tung dreamed -- by resettling the first 10,000 of the more 1 million Chinese whose homes would be drowned by the project.