Recently, the severe drought that has plagued central China caused water levels in Hubei Province’s nearly 1,400 reservoirs to drop so low that no water could be used for irrigation. Record low water levels in the Yangtze River forced the Three Gorges Dam, the world’s largest hydroelectric dam, to discharge 400 million cubic meters of water to ease the drought and facilitate shipping.
Just as China is becoming drier each year—its freshwater reserves declined 13% between 2000 and 2009 and it has experienced severe droughts in recent years— it has embarked on a campaign to vastly expand its hydroelectric power (HEP) capacity, a technology that depends completely on the availability of abundant water.
China already has half the world’s large HEP dams (25,800), which produce 213 GW of power. And while the west has mostly stopped building dams—the U.S. has only produced 80 GW of HEP in its history—China is forging ahead: Along the Yangtze River and its tributaries, 100 large dams are either being planned or built, and 43 additional dams are in the works for the Lancang (the Upper Mekong), Nu, Hongshui and Jiulong Rivers in China’s southwest.
Some Chinese officials want to speed up HEP development to make up for the last five years during which dam building was thwarted by the criticism of environmentalists, the public, and the international media. In 2004, development of 13 dams planned for one of China’s last free flowing rivers, the Nu River in Yunnan Province, was halted due to protests. The ban on dam building was lifted with the recent release of China’s 12th Five-Year Plan, which calls for limiting coal production growth to 3% a year (China depends on coal for 70% of its energy), getting 11.4% of primary energy consumption from non-fossil fuels, and cutting carbon dioxide emissions per unit of GDP by 17%.
China, which is choking on pollution from coal power plants, became the world’s leading emitter of carbon dioxide in 2006. By 2020, the country aims to get 15% of its energy from non-fossil fuel sources of which 9% will come from HEP. To reach that goal, China will have to double its output of HEP to 400 GW. This would replace 1.3 billion metric tons of coal each year and eliminate 2.3 billion metric tons of carbon emissions, according to The China National Energy Administration. China is depending on HEP, which produces little pollution, is the most reliable form of renewable energy, and is relatively inexpensive, to help reduce its consumption of dirty coal and provide electricity for its rapidly expanding urban areas and industries.
But a 2000 report by the World Commission on Dams found that, although dams have benefitted society, large dams often do not deliver the anticipated electricity, water, and irrigation services. They impact downstream livelihoods and bring misery to millions who must be relocated. And often they have damaging, sometimes irreversible, effects on biodiversity, rivers, watersheds and aquatic ecosystems. Peter Bosshard, policy director for International Rivers, wrote, “China’s new five-year plan essentially proposes to sacrifice the country’s arteries to save its lungs.”
The pros and cons of large dams are epitomized by the Three Gorges Dam (TGD), the world’s largest and perhaps most infamous hydroelectric dam.
First proposed by Sun Yat-Sen in 1918, championed by Mao Tse-Tung, and officially begun in 1994, the TGD was finally completed in 2008. Spanning the Yangtze River, it stands 607 feet high, 7575 feet wide, and creates a reservoir around 400 miles long from Chongqing to Sandouping where the dam is located. This year, its 32 power generators should be fully operational, enabling the TGD to produce 22.5 GW of electricity. China built the estimated $24 billion TGD to control the Yangtze’s flooding, to generate much needed power; and to enable large ships to sail from Chongqing all the way to Shanghai (with the help of a 5-tier shiplock).
But the TGD has already changed the Yangtze’s chemical balance, temperature, and flow, disrupting fish migration and damaging fisheries. When the river flowed naturally, it also helped cleanse the industrial pollution and sewage that was dumped from its banks; without that flow, pollution is causing algal blooms and accumulations of garbage. According to Probe International, an environmental advocacy group, 78,000 tons of garbage had been collected from the Yangtze near the dam by the end of 2010.
A report by International Rivers found that because the Yangtze carries over 500 million tons of silt into the reservoir each year, most of which remains there, water flows from the TGD much more quickly than before, eroding levees downstream, and potentially undermining the dam’s flood control effects. Accumulating silt also decreases a reservoir’s storage capacity and could eventually hinder navigation.
When less silt is carried down the river, downstream agricultural land and fish are deprived of its nutrients. And because less silt reaches the river’s mouth, 988 acres of coastal wetlands erode each year, and saltwater travels further inland, damaging croplands and endangering drinking water supplies.
The TGD sits on two major fault lines, and International Rivers reported that hundreds of small tremors have been recorded since 2006 when the reservoir started filling up. Some fear the reservoir’s 22 billion tons of water could trigger an earthquake.
But perhaps the most distressing aspect of the TGD is the social upheaval it has caused. The dam has submerged 13 cities, 140 towns and 1,350 villages. Originally residents were to be moved to higher ground nearby and provided with new homes and new jobs, but because erosion and landslides made some areas unsuitable for building, people ended up being resettled to 11 different provinces. The official number of people that have been relocated is 1.4 million, but Dai Qing, a Chinese investigative journalist and a Probe International Fellow, estimates it may actually be 4 million due to changes in resettlement plans. Many people never received resettlement money or job training, but in 2006, the Chinese government began retroactive payments to people who were relocated. In addition, hundreds of officials were prosecuted for embezzling an estimated 12% of the resettlement budget.
Criticism of the TGD’s impacts appears to be paying off. This week, China announced plans to deal with the dam’s environmental degradation by 2020. Efforts will be made to curb water pollution, preserve the environment, and protect biodiversity in the middle and lower stretches of the Yangtze. The government also promised to “stick to the principle of putting people first and promoting sustainable development in post-construction work.”
In Yunnan Province, the Lancang (Upper Mekong), Nu, and Jinsha Rivers begin on the Tibetan Plateau and run through the Three Parallel Rivers World Heritage Site, the epicenter of China’s biodiversity.
China is developing 8 large dams on the Lancang, which will affect the ecosystems and livelihoods of 60 million people downstream in Burma, Thailand, Laos, Vietnam and Cambodia. A 13-dam cascade is planned on the Nu River (Salween) that is shared with Thailand and Burma, and known for the richness of its cultural and biological diversity. And the Jinsha River, with 12 dams in the works, will eventually produce 10 times as much HEP as TGD; its major tributaries are also being dammed. On the Brahmaputra (Yarlung Tsangpo) River, a series of 5 dams will have impacts on India and Bangladesh downstream.
Even as China’s neighbors are planning big dams of their own, they are apprehensive about China’s race to dam the rivers, fearing ecological damage and natural disasters, and concerned that China will divert large amounts of water. Jiang Yu, a Foreign Ministry spokeswoman, countered that China would “fully consider impacts to downstream countries.” And officials contend that the dams will benefit their downstream neighbors, easing droughts and floods through regulating flow, and reducing China’s carbon emissions. If the dams don’t, however, they could trigger international conflicts.
Meanwhile, climate change is already responsible for warmer temperatures and changing precipitation patterns in China, causing droughts and lowering water levels in reservoirs. Severe flooding could threaten the safety of dams, while more droughts will drastically reduce the HEP and water that dams are meant to supply.
Zhang Boting, a vice secretary general of the China Society for Hydropower Engineering, has said that the droughts in southwest China only confirm the need for more hydropower facilities in the country, but not everyone is convinced. Chen Guojie, a researcher at the Sichuan Mountain Hazards and Environment in Chengdu, warned, “The dams are built to provide energy for the next hundred years, according to plans based on current natural conditions. But these conditions are changing fast. Not taking climate change into account means that not only are the dams…harmful for the environment, they might very well prove dysfunctional in the not-so-distant future.”
International Rivers, which works to protect rivers and rights, stresses the importance of protecting the environment and biodiversity. The organization advocates building fewer but better dams, putting resources into the development of renewable energy technologies and energy efficiency, and removing old dams that have harmed the environment. It says official estimates show that China could reduce its energy use 100 GW by 2020 through demand side management and energy efficiency, and that it has the potential to generate 1,000 GW of wind power on land, and another 700 GW offshore.
But for now, China must use every means possible—HEP, nuclear power, and other renewables, as well as energy efficiency—as it attempts to get pollution under control. Meanwhile, despite the documented negative impacts of large dams, HEP is experiencing something of a renaissance as countries around the world seek to boost their energy output. So as long as the international community continues to squabble about global warming and fails to come together to curb carbon emissions, each and every river will be in danger of being dammed.