By Peter Bosshard
The Three Gorges Dam on the Yangtze River is the world`s largest hydropower project. It has often been touted as a model for dam building around the world. Now the Chinese government has officially acknowledged the project`s serious social, environmental and geological problems. What are the lessons from the Three Gorges experience for Northeast India?
For many years, Chinese leaders have celebrated the mega-dam on the Yangtze as a symbol of the country`s economic and technological progress. With a capacity of 18,200 megawatts, the hydropower project isindeed a master piece of engineering. Pouring 27 million cubic meters of cement, the government completed the project ahead of schedule in 2008. Officials insist that with a cost of $27 billion (Rupees 1,22,472 crores), the project was built within budget. Others claim that its real cost may amount to as much as $88 billion (Rupees 3,99,168 crores).
Costs and benefits
The Three Gorges Dam generates 2 percent of China`s electricity, and substitutes at least 30 million tons of coal per year. However, the hydropower plant was not the only option for replacing coal. While the dam was under construction, the energy efficiency of the Chinese economy actually decreased. According to Douglas Ogden of the Energy Foundation, it would have been “cheaper, cleaner and more productive for China to have invested in energy efficiency” rather than new power plants.
The Three Gorges Dam has displaced more than 12 lakh people. Hundreds of local officials were found to divert compensation money into their own pockets, but protests against such abuses were frequently oppressed. Because it no longer controls the economy and land is scarce, the government was not able to provide jobs and land to the displaced people as promised. Unlike India and most other countries, China has set up a program to provide pensions to the 18 million people displaced by dams in the past.
Damming the Three Gorges caused massive impacts on the ecosystem of the Yangtze, Asia`s longest river. The barrage stopped the migration of fish, and diminished the river`s capacity to clean itself. Pollution from dirty industries along the reservoir is causing frequent toxic algae blooms. Commercial fisheries have plummeted, the Yangtze river dolphin has already been extinct, and species such as the Chinese Sturgeon are threatened by the same fate. Due to dam building and pollution, rivers and lakes around the world have lost more species to extinction than any other major ecosystem.
Struggling with unexpected impacts
While the social and environmental problems had been predicted, government officials were not prepared for the massive geological impacts of the Three Gorges Dam. The water level in the reservoir fluctuates between 145 and 175 meters every year. This destabilizes the slopes of the Yangtze Valley, and is triggering frequent landslides. According to Chinese experts, erosion affects half the reservoir area, and 178 kilometers of riverbanks are at risk of collapsing. More than 300,000 additional people will have to be relocated to stabilize the banks of the reservoir.
Since most of the silt load from the Yangtze`s upper reaches is now deposited in the reservoir, the downstream regions are being starved of sediment. As a consequence, up to 4 square kilometers of coastal wetlands are eroded every year. The Yangtze delta is subsiding, and seawater intrudes up the river, affecting agriculture and drinking water supplies. An international team of scientists recently found that no less than 47.2 crore people have likely been affected by the downstream impacts of large dams around the world, and that these impacts are often neglected during the planning of such projects.
Scientists agree that the reservoirs of high dams can trigger earthquakes. The Three Gorges Dam sits on two fault lines, and hundreds of small tremors have been recorded since the reservoir began filling. While the dam has been built to withstand strong earthquakes, the villages and towns in its vicinity have not. As global dam building increasingly moves into mountain areas with active tectonic faults, such as the Himalayas and their foothills, the seismic risks of reservoirs will increase.
Hydropower projects have often been proposed as a response to global warming, yet the Three Gorges Dam illustrates how climate change creates new risks for such projects. In a nutshell, past records can no longer be used to predict a river`™s future streamflow. The dam operators planned to fill the Three Gorges reservoir for the first time in 2009, but were not able to do so due to insufficient rains. The current year has brought Central China the worst drought in 50 years. Like many other projects around the world, the Three Gorges Dam is facing serious risks and losses due to the vagaries of climate change.
Change of opinion
Scientists had warned of the Three Gorges Dam`s impacts throughout the 1980s and 1990s. Yet their opinions were ignored and silenced. During the construction phase, the giant project, which had originally been championed by Mao Zedong, was frequently visited by government and party leaders. It has also served as a tour stop for many visiting government delegations from Asia, Africa and Europe.
In recent years, the Chinese government has quietly toned down its enthusiasm for the project. “We thought of all the possible issues,” Weng Lida, the secretary general of the Yangtze River Forum, told the Wall Street Journal in August 2007. “But the problems are all more serious than we expected.” When the dam was inaugurated in 2008, the Chinese president and his prime minister were conspicuously absent. And on May 18, China`™s highest government body for the first time acknowledged the serious problems at the Three Gorges. “The project is now greatly benefiting the society in the aspects of flood prevention, power generation, river transportation and water resource utilization,” the government maintained, but it has “caused some urgent problems in terms of environmental protection, the prevention of geological hazards and the welfare of the relocated communities.”
While the dam on the Yangtze has been completed, it is not too late to draw lessons from the experience for other mega-projects around the world. The Three Gorges Dam is a test case for the social and environmental costs, the seismic and hydrological risks, the complex upstream and downstream impacts that may be expected for the proposed projects on the Brahmaputra and its tributaries.
(Peter Bosshard is the Policy Director of International Rivers.)