The Environmental Consequences of the Three-Gorges Dam

E76a69f0da6fca467727bab834c8aec2_1 Mara Hvistendahl in Scientific American:

For over three decades the Chinese government dismissed warnings from scientists and environmentalists that its Three Gorges Dam—the world’s largest—had the potential of becoming one of China’s biggest environmental nightmares. But last fall, denial suddenly gave way to reluctant acceptance that the naysayers were right. Chinese officials staged a sudden about-face, acknowledging for the first time that the massive hydroelectric dam, sandwiched between breathtaking cliffs on the Yangtze River in central China, may be triggering landslides, altering entire ecosystems and causing other serious environmental problems—and, by extension, endangering the millions who live in its shadow.

Government officials have long defended the $24-billion project as a major source of renewable power for an energy-hungry nation and as a way to prevent floods downstream. When complete, the dam will generate 18,000 megawatts of power—eight times that of the U.S.’s Hoover Dam on the Colorado River. But in September, the government official in charge of the project admitted that Three Gorges held “hidden dangers” that could breed disaster. “We can’t lower our guard,” Wang Xiaofeng, who oversees the project for China’s State Council, said during a meeting of Chinese scientists and government reps in Chongqing, an independent municipality of around 31 million abutting the dam. “We simply cannot sacrifice the environment in exchange for temporary economic gain.”

The comments appeared to confirm what geologists, biologists and environmentalists had been warning about for years: building a massive hydropower dam in an area that is heavily populated, home to threatened animal and plant species, and crossed by geologic fault lines is a recipe for disaster.