Only two known species build dams – beavers and humans.
Beavers build dams delicately, their wood, stone and mud structures carefully balanced to create comfortable marsh habitats, form cozy homes, and to quiet those annoying babbling brooks. Although humans sometimes find beaver dams bothersome, scientific evidence suggests that beaver dams are ecologically beneficial filtering sediments that would otherwise harm spawning fish.
Humans, by contrast wield dams like bombs – they explode the world around us.
At first glance hydroelectric dams seem like a smart solution: they’re immune from volatile fuel prices, don’t involve the burning of climate changing fuels, and they can generate tremendous amounts of electricity. Given this context it’s unsurprising that worldwide there are more than 48,000 large dams, generating 19% of the world’s total electricity.
But as the trailer for the short documentary Damocracy makes clear, there’s a significant human and environmental cost to these dams. Here is a breakdown of some of the most troubling.
Brazil: The Belo Monte Dam
Since the mid-1970s the Brazilian government has tried to build a hydroelectric dam, called the Belo Monte, on the mouth of the Amazon’s Xingo River. If built, the Belo Monte will be the world’s third largest dam. It will also displace 30,000 people, many of them members of indigenous tribes, and flood 40,000 hectares of rainforest. The Belo Monte will divert up to 80% of the Xingu River from its original course diminishing fisheries, destroying water quality and the livelihoods of those dependent on the river for survival. The displaced will likely turn to illegal logging, only hastening the imperiled Amazon’s demise. Further, Philip Fearnside of the National Amazon Research Institute has calculated that the flooded forests would release significant amounts of methane – a greenhouse gas 25 times more potent than CO2 – as the flooded trees, hanging air plants, and thick, water storing, bromeliads decay. Dams, it seems, are not a carbon-neutral energy source.
The Brazilian Federal constitution states that any interference in indigenous areas requires a federal hearing that includes the voices of indigenous groups. On November 9th of 2011, a federal court in Brasilia ruled that free, prior, and informed consent from indigenous groups was not necessary because the dam’s infrastructure would not be situated on tribal land.
As of June of last year construction had quietly begun on the Belo Monte.
China: Three Gorges Dam
While much attention is focused on China’s coal burning activities, since 1949 China has also been busy building the equivalent of one large dam per day. China is now home to more dams than any other nation – roughly half of the world’s large dams. Of these, the most famous, or perhaps infamous, is the Three Gorges Dam. Straddling China’s Yangtze River, the Three Gorges is the world’s largest hydroelectric dam. Its construction displaced more than 1.2 million people, and flooded 13 cities, 140 towns, and 1,350 villages.
The dam’s negative effects did not end with its construction. Submerging hundreds of factories, mines and waste dumps, along with the presence of massive industrial centers upstream are turning the reservoir into a festering bog of sewage, silt and industrial pollutants. Erosion of the reservoir and downstream riverbanks is causing landslides, and threatening one of the world’s biggest fisheries in the East China Sea. The weight of the reservoir’s water has many scientists worried that the dam might trigger earthquakes. In 2011, China’s highest government body for the first time officially acknowledged the “urgent problems” of the Three Gorges Dam.
Rather than pursuing with caution, however, China is doubling down. Between 2011 and 2016 the Chinese government plans to approve 140 gigawatts of new hydroelectric capacity. This is more than double the hydroelectricity capacity that dam happy countries like Brazil, Canada, and the United States, have built- total.
Turkey: Ilusu Dam
Nestled along the banks of the Tigris River in what was once Mesopotamia lies the 11,000 year old, continuously inhabited, city of Hasankeyf. This ancient, southeastern Turkish city meets 9 out of the 10 criteria for a World Heritage site, and was deemed a protected area by the Turkish government in 1981. Much of Hasankeyf, however, is also within the 31,000 hectare region that’s slated to be flooded upon completion of Turkey’s proposed Ilisu Dam. The Ilisu Dam rated at 1,200 MW will, according to official Turkish government numbers, generate some 3,800GWh of hydroelectric power annually making it the largest hydroelectric dam in Turkey. Detractors argue that in addition to destroying this historic site, the dam would displace up to 78,000 people and wipe out the region’s biodiversity. Based on these grounds the dam lost international funding in 2008.
Turkish officials argue that the dam will only displace 15,000 people, that nearly every city in Turkey is of historical significance, and that Turkey’s growing energy needs, along with its increasing role as a regional energy market make the Ilusu necessary.
It is easy from the casual comfort of my coal powered laptop, in my oil heated home to play armchair environmentalist and to lambast these nations for building such obviously deleterious structures. But electricity is lovely and kerosene lanterns, which are often used when electricity is unavailable, kill as many as 1.5 million people a year from fumes alone. In the Canadian province of Quebec, where hydro accounts for more than 92% of the province’s electrical supply, electricity doesn’t just power cell phones and television sets, but also provides heat in a region where subzero temperatures are the daily average for half of the year. Large dams do more than provide electricity – half of the world’s dams were built primarily for irrigation and 30-40% of irrigated farmland depends on dams for their water source. It’s mighty difficult to tell people that they shouldn’t eat.
What seems lacking are effective mechanisms to help us understand and balance the benefits of any one dam with its ecological and social costs, and a method of communication by which those who are affected can have their voices heard. Because increasingly we know this much: dams aren’t always worth it.
Even as Brazil, Turkey, and China ramp up their dam development, the United States seems to be winding down, under the realization that the erosion, habitat loss, and significant alteration of key ecosystems of many dams has not been worth the cost. Over the past few decades, supported by the nonprofit organization American Whitewater, dam removal has been studied or successfully undertaken on Oregon’s Rogue, Sandy and Hood Rivers, Idaho’s Bear River, Washington’s Trout Creek and Montana’s Clark Fork. Over the past fifty years the US has successfully removed 600 dams.