August 16, 2011

Dam Water in China: Is It Worth It?

Meagan Hawes

Meagan Hawes

Guest Blogger

Undergraduate, Environmental Engineering, JHU

In western China, massive dams are being built along 12 waterways. The dams are supposed to aid economic development—but experts are saying it’s likely that the dams will do more harm than good.

Reservoir created by dam, the Pamir Mountains

When China pledged to cut its greenhouse gas emissions by 40-45 percent of the 2005 levels at the Copenhagen Summit, the latest in a series of UN Climate Change conferences held in 2009, its energy agenda rested on the construction of dams. These dams are emblems of economic development. They create hydropower and control floods. They spread irrigation and, according to their advocates, they increase the nation’s agricultural production via increased irrigation water supply. They are touted as technological marvels, a point of national pride.

Under the New Socialist Countryside program, the Chinese government has pledged $62 billion (U.S.) to construct 12 large dams on China’s western, alpine rivers. In a 2010 paper for the Chinese Journal of Geotechnical Engineering, government engineer Ming-Jiang Deng describes the construction as “an effective measure to control and regulate rational allocation of water resources.” The Chinese Foreign Ministry adds that China is “carrying out [all dam construction efforts] according to the principles of sustainable development.” Dams promise the export of food and power to the heavily populated eastern coast, and therefore the sustained maintenance of the nation. And while all China’s populations deserve food and power, the Ministry’s aerial view fails to acknowledge the ways in which dams degrade riverbeds.

Dams create stark environmental degradation. Local agriculture is forced to change because of silt that accumulates in dam reservoirs and because of the altered patterns of water distribution. As water seeps into the pores of underlying rock, the tolerable stress of shifting earth decreases, leaving the area vulnerable to earthquakes. Reservoirs, because they are darker than the snowy ecosystem, absorb more solar radiation, transfer more heat, and therefore can accelerate glacial melt. (It’s ironic that some dams were originally intended to control glacial melt.) Dams decrease biodiversity, and they increase the frequency of landslides. New York Times reporter Jim Yardley notes that dams have a legacy of disruption so pronounced that “many environmentalists contend that electricity generated by large dams should not be considered renewable because of the [accompanied] social and environmental damage.”

Typical foothill town in the Pamir Mountains

Further, hydrologist Chen Guo-Jie tells Circle of Blue reporter Rachel Beitarie, “These dams are built to provide energy for the next 100 years, according to plans based on current natural conditions. But those conditions are changing fast… [The dams] may very well prove dysfunctional in the not-so-distant future.” From an environmental perspective, then, large dams are not sustainable.

So if dams are not a sustainable source of energy, and coal is not a sustainable source of energy, what is? Few analysts believe a revolution of wind, solar, or nuclear power could progress rapidly enough to support the burgeoning Chinese population. Jonathan Sinton, China’s program director at the International Energy Agency, says, “There are no ideal choices.”

Sinton and other are trying to unravel these questions. But there are other worrisome questions as well. What would it mean for the farmers along the riverbank—and for the Shanghai dwellers relying on the western crops, and for the thousands in a downstream Indian river delta—if the 124 meters of a newly constructed dam succumbed to an earthquake and fell? Does the hydropower produced, releasing fewer greenhouse gasses than coal, merit the degradation of riverside ecosystems and cultures?


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