As the costs of subduing nature to build mega dams become more evident, we should combine the wisdom of traditional approaches with the potential of modern technology to devise policies that respect the limits of our ecosystems, writes Peter Bosshard.
After he visited the country in 2001, Ronnie Kasrils exclaimed: “China today is a construction engineer’s dream…. Nowhere is this better symbolised than at the Three Gorges Dam on the Yangtze River.” The Yangtze dam is the world’s largest hydropower project and has often been touted as a model for dam builders around the world. Now the Chinese government has admitted the project’s serious social, environmental and geological problems.
What are the lessons from the Three Gorges experience for Africa?
The Three Gorges Dam is indeed a masterpiece of engineering. In spite of its daunting complexity, the government completed it ahead of schedule, in 2008. The dam generates 2 per cent of China’s electricity, and obviates the need for at least 30-million tons of coal a year. Its cost has been estimated at between $27bn and $88bn.
Like southern Africa, China has pressing water and energy needs. Yet the Three Gorges Dam was neither the cheapest source of energy nor the best option for replacing coal. While the dam was under construction, the country’s economy actually became more wasteful in its use of energy. 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.
The project’s social and environmental cost is staggering. The Three Gorges Dam has displaced more than 1.2m people. Hundreds of local officials diverted compensation payments into their own pockets. Because it no longer controls the economy and land is scarce, the government could not provide the jobs and land to the displaced people that it had promised.
Damming the Three Gorges caused huge effects 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 attracted by the reservoir is causing frequent toxic algae blooms. The number of commercial fisheries has plummeted, the Yangtze river dolphin has become extinct and other species face the same fate.
Government officials expected social and environmental problems, but were not prepared for the dam’s massive geological effects. The water level in the Three Gorges reservoir fluctuates between 145m and 175m every year. This destabilises the slopes of the Yangtze Valley and triggers frequent landslides. Erosion affects half the reservoir area, and almost 200km of banks are at risk of collapsing. More than 300000 additional people will have to be relocated to stabilise the reservoir banks.
Since most of the Yangtze’s silt load is now deposited in the reservoir, the downstream regions are being starved of sediment. As a consequence, up to 4km² of coastal wetlands are eroded every year. The Yangtze delta is subsiding, and seawater intrudes up the river, affecting agriculture and drinking water.
The Three Gorges Dam illustrates how the vagaries of climate change create new risks for hydropower projects. In a nutshell, past records can no longer be used to predict a river’s future flow. 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. This year has brought central China the worst drought in 50 years, which is again reducing the power generation of the Three Gorges Dam and hundreds of other dams.
On 18 May, the Chinese government acknowledged for the first time the serious problems of the dam. “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 had “caused some urgent problems in terms of environmental protection, the prevention of geological hazards, and the welfare of the relocated communities”.
The Three Gorges Project was a model of dam building all around the globe. Once it was completed, Chinese companies began exporting the technology they had acquired. The Three Gorges Corporation is developing several projects in Africa, and Sinohydro, the world’s biggest hydropower contractor, uses the Three Gorges Dam as a reference for international contracts. Governments and utilities everywhere should consider the lessons from the dam as they chart their own strategies for the energy sector.
The Three Gorges experience demonstrates that rivers are highly complex ecosystems, and that the effects of dams cannot be fully predicted and mitigated. Because of dam building, water withdrawals and pollution, fresh-water ecosystems have lost more species than any other major ecosystem. The services that rivers provide in terms of fisheries, water supply, flood protection and nutrients must be valued and fully integrated into decisions affecting their watersheds. Dams on a river’s main stream are particularly damaging, and should be built only if all other options have been exhausted.
Chinese scientists predicted many of the effects of the Three Gorges Dam; yet their voices were silenced in what the government claimed was the national interest. In multibillion-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 fully transparent and participatory decision-making process.
China spent tens of billions of dollars on the resettlement programme for the Three Gorges Dam. Yet because the affected communities had no say in the decisions that determined their futures, the project resulted in widespread impoverishment and frustration. Local communities need to be fully involved in decision-making processes about such projects from the beginning.
Africa is already more dependent on hydropower than any other continent. As the Three Gorges Dam demonstrates, global warming increases the financial and geological risks of dams. Rainfall and stream flows are becoming less predictable. Decentralised and diversified projects make the water and energy sectors more resilient to climate change than sinking billions of dollars into centralised water storage.
The World Commission on Dams, which was chaired by Kader Asmal, proposed a new framework for decision-making on dams in 2000. This framework gives equal weight to social, economic and environmental concerns, and brings all interest groups into the decision-making process.
Now that climate change has raised the stakes and renewable energy technologies have seen their breakthrough, the commission’s recommendations have become all the more relevant.
A few hundred kilometres north of the Three Gorges Dam, the waterworks of Dujiangyan have provided irrigation and flood protection to the plains of Sichuan for more than 2000 years. While the Three Gorges Dam reflects Mao Zedong’s conviction that nature must be conquered, the sophisticated waterworks express the Taoist philosophy of working with nature. As the costs of subduing nature become more evident, we should combine the wisdom of traditional approaches with the potential of modern technology to devise policies that respect the limits of our ecosystems.
Bosshard is the policy director of International Rivers. His report, China’s Environmental Footprint in Africa, was published by the South African Institute of International Affairs.