The past year has seen China’s government reinvigorate its programme for constructing hydro-electric dams. This emphasis on hydro-electric power draws its logic from the combination of the need to enhance energy supplies and the desire to constrain the rise of greenhouse gas emissions. Reasonable though these goals appear, the manner of implementation highlights a number of contradictions.
The five year plan for 2011-2015 emphases the role of renewable energy and establishes ambitious target for raising the share of non-fossil fuel as total energy consumption from 8.3% in 2010 to 11.4% in 2015 and 15% by 2020. With a temporary slowdown in the construction of nuclear plants after the Fukushima accident, the government is pushing ahead with all forms of renewable energy: solar, wind, bio-energy, geothermal and, of course, hydro.
China is now the world’s largest producer of hydro-electricity ahead of the USA and it has the largest installed capacity. Total hydro capacity reached 220 GW by end 2011, up 15 GW over the year. Another 10 GW had been added by April of this year. The government aims to reach 300 GW by 2015 and 400 GW by 2020. To put these numbers in perspective, the Three Gorges dam has a capacity of 21 GW. Its construction was approved in 1992 when the country’s total electricity generating capacity was 170 GW. Total capacity is now about 1,100 GW and will exceed 1,600 GW by 2020.
The most active area for dam building is along the upper reaches of the Yangtze River in Yunnan and Sichuan Provinces. In the last three months, the central government has approved 6 major new dam projects totalling 10 GW. This would bring the total capacity of dams under construction in this region alone to nearly 60 GW. Four of these dams are very large and together would amount to 40 GW. A further dam with a capacity of 6 GW, at Hutiaoxia, would flood an area of great natural beauty and displace an estimated 100,000 people. This has drawn a lot of criticism from within and outside China. Although the project was shelved a few years ago, it still may be revived.
A cascade of eight dams is planned along the Mekong (Langcang) River. Four are completed and have a combined power generation capacity of 9 GW. Along the Salween (Nu) River, China had planned a 13 dam cascade with a total capacity of 21 GW. These plans were suspended in 2004 in response to pressure from domestic environmental groups in China but were revived in February 2011.
The problems associated with large dams have been well documented around the world, and China has been no exception. Environmental damage includes the destruction of biodiversity on land and in the rivers, landslides from unstable slopes, the accumulation of industrial and human waste in the lakes, and the production of greenhouse gases from rotting vegetation and from the massive use of steel and cement in construction. Most dams involve the relocation of communities, especially in regions with a high population density and for the biggest dams, and damage from earthquake is a significant risk in seismically active areas such as south-west China. Finally, silting in the lakes tends to significantly reduce the contribution of many large dams to way below initial expectations
In this way the continuing construction of large dams exposes a fundamental contradiction in China’s energy policy. The government appears to want to protect the global environment from the greenhouse gases emitted by thermal power stations, and yet the strategy of building large dams is placing additional pressure on the already stressed environment within its own borders.
The growing appreciation of these environmental costs has apparently led to renewed emphasis on the construction of small-scale dams with an individual capacity of less than 50,000 kW, for local power consumption. Between 2011 and 2015 an additional 15 GW of such dams are to be built, bringing the national total to 74 GW. Welcome though this initiative is, it does not seem to reflect any reduction in emphasis on the construction of large dams.
A second contradiction arises from the growing unreliability of rainfall to feed the water flows which drive the turbines. Last year saw a serious drought in central and southern China which reduced the national output of hydro-electricity by 3.5% despite new dams being commissioned. The output from the Three Gorges dam itself fell by 7%. The southern provinces of Guandong, Guangxi and Yunnan continue to experience drought and, as a consequence, are being subjected to power rationing. In contrast, heavy rain in central China has allowed this region to raise its hydropower output in May of this year by 78% compared to the same period last year. This has allowed total national hydropower output to rise. The growing unreliability of the rainfall across China may be the result of global climate change.
A further consequence of global climate change may be seen in the source regions for China’s large rivers. The total volume of ice held in the glaciers of the Himalaya and Tibet seems to be declining, though a great deal of uncertainty remains. In simple terms, the reduction of volume of a glacial body results in: an initial rise in the volume of water flow during the melt season, with the risk of more frequent floods or higher levels of flood water; possible catastrophic collapse of part of the glacial body, causing landslides, mudflows and floods; and an eventual reduction in total annual water flow. Such phenomena would exacerbate the unreliability of water flows to China’s dams and eventually result in a long-term decline in hydro-electricity production.
The final contradiction is international in character and concerns the impacts of the dams on Mekong, Salween and Red Rivers on neighbouring countries. These rivers are vital to the livelihoods of tens of millions of people, many of whom are very poor. Some 300 million people live in the Greater Mekong Region which includes Yunnan Province of China, Thailand, Laos, Vietnam, Cambodia and Myanmar. The last four of these are the poorest nations in Southeast Asia in terms of per capita GDP. The population of the Mekong River Basin alone is 70 million. The Lower Mekong River is second only to the Amazon in terms of aquatic biodiversity, and is one of the richest stocks of fresh-water fish, providing some 50-80% of the animal protein intake of the population.
The downstream effects of these dams include: reduction of annual volume of water flow, especially during the phase of reservoir filling, and of water quality; changes in the timing of water flows; reduction of the flow of water and silt during the flood season; and reduction of biodiversity of aquatic animal and plant life. Collectively these consequences reduce the quantity of water available for human use, reduce crop yields and reduce fish stocks.
Despite the seriousness of the impacts on its neighbours, China has failed to enter into any river basin management agreement. The Mekong River Commission provides a forum for river basin planning and collaboration among the participating riparian states. China’s refusal to participate not only prevents the downstream states engaging in meaningful consultations with China on issues of concern, but also constrains their access to information on China’s plans for dam construction and to hydrological data. This approach to transboundary river basin management seriously undermines China’s stated position of seeking to collaborate with its neighbours on issues of shared concern.
China’s international search for oil, gas and minerals may be drawing international attention, but its strategies for using water resources are a much greater cause for concern in East Asia, not least within China itself. The continued construction of such numbers of large dams poses significant threats to the livelihoods of large numbers of people and to the environment both within China and in neighbouring countries. This in turn may undermine domestic and regional stability. New strategies are needed which place greater emphasis on small-scale energy generation, energy efficiency and economic restructuring.