With a capacity of 18,200 megawatts, the Three Gorges Dam is the world’s biggest hydropower project. In spite of its daunting complexity, the government completed the project ahead of time in 2008.
The Yangtze dam generates 2 percent of China’s electricity and substitutes at least 30 million tons of coal per year. Yet its social, environmental, geological and financial costs are staggering. Here is a brief overview of the main problems:
• Displacement: The Three Gorges Dam has submerged 13 cities, 140 towns and 1,350 villages, and displaced more than 1.2 million people. Many resettlers were cheated out of their compensation payments and did not receive the new jobs or land that the government had promised. While some of the newly built towns have recovered from the initial shock of displacement, others are beset by widespread unemployment and impoverishment.
• Ecological collapse: Damming the Three Gorges caused massive impacts on the ecosystem of the Yangtze, Asia’s longest river. The reservoir has turned the once mighty river into a stagnant garbage dump with frequent toxic algae blooms. Because the barrage stopped fish migration, commercial fisheries have plummeted, the Yangtze river dolphin has been extinct, and other species are facing the same fate.
• Erosion: Government officials were prepared for social and environmental problems, but not for the dam’s massive geological impacts. The strong fluctuation of the water level in the Three Gorges reservoir destabilises the slopes of the Yangtze Valley, and triggers frequent landslides. Erosion affects half the reservoir area, and more than 300,000 additional people will have to be relocated to stabilise the reservoir banks.
• Downstream impacts: The Yangtze River carries more than 500 million tons of silt into the reservoir every year. Most of this is now withheld from the downstream regions and particularly the Yangtze delta. As a consequence, up to four square kilometres of coastal wetlands are eroded every year. The delta is subsiding, and seawater intrudes upriver, affecting agriculture and drinking water. Because of the lack of nutrients, coastal fisheries are also suffering.
• Susceptibility to climate change: The Three Gorges Dam illustrates how the vagaries of climate change create new risks for hydropower projects. 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 five decades, which has again sharply reduced the power generation of the Three Gorges and other dams. Ever more unreliable rainfalls put a big question mark behind the benefits and the economics of the Three Gorges Dam.
• Financial cost: The official cost of the Yangtze dam is US$27 billion. Critics argue that if all hidden costs are included, the project’s real price tag amounts to $88 billion. It would have been cheaper to generate electricity and replace coal through other means. While the dam was under construction, the energy efficiency of China’s economy decreased. According to the Energy Foundation in the US, it would have been “cheaper, cleaner and more productive for China to have invested in energy efficiency” rather than new power plants.
On May 18 the State Council, China’s highest government body, for the first time acknowledged the dam’s serious problems. “The project is now greatly benefiting the society in the aspects of flood prevention, power generation, river transportation and water resource utilisation”, 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.”
The Three Gorges Dam has served as a model for projects in Cambodia and many other countries. Three Gorges contractors such as Sinohydro and Gezhouba and other Chinese companies are currently building the Da Dai, Kamchay, Kirirom III, Lower Stung Russey, Stung Atay and Stung Tatay dams on Cambodian rivers. Chinese companies have also signed a memorandum of understanding to develop the Sambor Dam on the Mekong, and have proposed several projects on the Stung Cheay Areng and Srepok rivers.
What lesson does the Three Gorges Project hold as Cambodia considers its future hydropower strategy? First and foremost, the Yangtze dam shows that large dams on major rivers are massive interventions into highly complex ecosystems. Their impacts can occur thousands of kilometres away and many years after construction has been completed. It is impossible to predict and mitigate all social and environmental impacts of such projects.
The Three Gorges experience demonstrates that damming the mainstream of major rivers is particularly damaging, in that it will interrupt the migration of fish and the transport of sediments throughout a river’s ecosystems. As the World Commission on Dams recommended in its path-breaking report, Dams and Development, a river’s mainstream should not be dammed as long as there are other options.
A Strategic Environmental Assessment prepared for the Mekong River Commission (MRC) predicts that damming the lower Mekong mainstream would cause the loss of riverine and marine fisheries, reduce the agricultural productivity in the floodplains of the Tonle Sap and the Mekong Delta, and erode the delta’s coastline and river channels. All these impacts have been borne out by the Three Gorges Project.
The MRC was right to recommend that the lower Mekong should not be dammed in the next 10 years, and the Cambodian government has good reasons to call for caution regarding the proposed Xayaburi Dam in Laos. It should be equally cautious as it considers the Sambor Dam in Kratie Province.
Chinese scientists predicted many of the impacts of the Three Gorges Dam, yet their voices were silenced in what the government claimed was the national interest. In multi-billion dollar projects, the national interest is often taken hostage by political prestige, bureaucratic power struggles, and the generous kickbacks of a bribery-prone industry. These vested interests need to be balanced and held accountable by a transparent and participatory decision-making process.
Finally, China spent tens of billions of dollars on the resettlement program for the Three Gorges Dam. But because the affected people were excluded from decision-making, the programme often ignored their needs and desires, and resulted in wide-spread impoverishment and frustration. The experience of the Yangtze dam demonstrates that affected communities and other stakeholders should be involved in the decision-making regarding large infrastructure projects from the beginning.