Driven by a constantly expanding need for electricity, Chile is considering building seven new dams and a transmission line through its southern wilderness. This isolated land of condors and monkey puzzle trees is home to the third largest reserve of frozen freshwater in the world—the Southern Ice Field. Critics say the environmental risks have not been fully examined, and the risk to southern Chile's unique ecosystems is unacceptably high. Proponents of the dam project argue that hydroelectricity is a clean source of energy, just waiting to be tapped. Chile needs the 3500 MW/yr of power to meet its development goals and lacks indigenous oil or coal reserves. Moreover, the electricity from the dams would displace dirty generation, greatly reducing Chile's greenhouse gas emissions. Give all the benefits, why are so many people, within Chile and without, so opposed to the dams—opposed to the point of preferring new coal plants?

The HidroAysen project is the most ambitious dam proposal in the history of Chile. Along with proposing the construction of 5 dams on two of Patagonia's most pristine rivers, the Pascua and Baker, it plans on building a 2000 km high-voltage transmission line North to Santiago, creating the world's longest clear-cut. The proposed dams would flood rare temperate rainforests and some of Patagonia's best ranching lands. The rainforest areas that the dams and transmission lines would eliminate do not exist anywhere else on the planet—more than 50% of the plant species found in southern Chile are found nowhere else. Along with altering Chile's environment from the south to the Central Valley, the project threatens future damming of other rivers in Patagonia. Activists fear, that once the transmission line is in place, rivers such as the Puelo, Yelcho, Palena and the Futaleufu will also be scheduled for damming.

With virtually no coal, oil or natural gas, Chile imports more than 95% of its fossil fuels. Half the country's electricity comes from plants fueled by Argentinean oil or gas and Columbian coal. The other half comes from existing hydropower schemes, many of them in the central zone around the Biobío River. As a result, Chile has the most expensive energy in South America. Add to that often contentious relationships with neighboring countries and Chile's energy position is a disaster waiting to happen.

A land of lamas, alpacas and volcanoes.

For example, in the summer of 2008–09, Argentina cut off gas supplies to Chile. At the same the same time, months of drought had reduced Chile's hydropower capacity, causing widespread blackouts. The powerful earthquake near Concepción in February, 2010, caused further disruptions and blackouts across the central grid. Little wonder that Chilean leaders want to expand domestic energy production. But not everyone in Chile agrees with damming the Patagonian glacial rivers.

In two news focus articles in the July 23, 2010, issue of Science, science writer Gaia Vince exposes dissension among environmentalists and local residents regarding the dam plan. Some may recall that Vince is a previous winner of our coveted Crank of the Week award. Fortunately, Ms. Vince is a better reporter than she is a scientist or visionary. In “A Craving for Hydropower,” Ms. Vince lays out the problem this way:

The reason Chile must build at least seven new hydrodams, sponsors of the projects say, is that forecasts show the country desperately needs more electricity—and that it must come from Chilean sources. Environmentalists and independent energy analysts have challenged this view; they argue that by improving efficiency and investing in renewable energy, Chile could find more than enough power within its borders for at least a decade—and without more dams. So far, however, energy planners have not been persuaded.

According to Claudio Zaror, a chemical engineer at the University of Concepción and an energy adviser to the government: “Every year, the country needs an extra 500-MW capacity—another 8% a year,” Finding claims that the nation's energy needs can be fulfilled through conservation and other renewables, Zaror says, “we have to get that energy from somewhere. Environmentally and economically, hydropower is our only feasible option.”

A 2009 study by a consortium of Canadian and Chilean energy analysts disagrees. In their report, titled Are Dams Necessary in Patagonia?, Stephen Hall and colleagues say that Chile's projected electricity requirements to 2025 can be met by existing hydro-plants and the newly approved coal plants. But dam proponents point to changes in the El Niño Southern Oscillation (ENSO) that have brought diminished rainfall and drought conditions to the central part of Chile.

Reduced rainfall has had a significant impact on Chile's existing hydroelectric production. “During the 2008 drought, less than 15% of the baseload was met by hydro, and we had to import diesel for the power plants at $118 per barrel,” Zaror says. He contends that Patagonia will not be affected as severely by drought, while the Global Change Research Center in Santiago is predicting that by 2050 average rainfall will decline in the central region by 15% and that by 2065 the flow of the Maipo River, a major source of the nation's hydropower, would drop 70%. But evidently global warming both gives and takes away: warming temperatures have 92% of the country's glaciers retreating, their melt-water providing the southern rivers with continued strong flow.

Possible problems with the ambitious dam building scheme include the fact that most of Chile is seismically or volcanically active. Four major tectonic plates are present within or close to Chile's borders, the Antarctic Plate, the Nazca Plate, the Scotia Plate and the South American Plate. The mountains of Chile are a result of the collision of the Nazca and South American plates, which form a subduction zone along the coast. The Great Chilean Earthquake or Valdivian Earthquake of May 22, 1960, was the most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale (The MMS replaced the more common Richter magnitude scale in the 1970s).

Chile's National Geology and Minerals Service required that seismic surveys be performed before granting permission for dam construction. In 2007, one month after XSTRATA, a company hoping to build three dams on the river Cuervo, submitted their report declaring the area to be seismically inactive, a massive earthquake struck, dislodging boulders into the river's fjord and triggering a tidal wave that killed people on the opposite bank. The government threw out the report.

Earthquakes and volcanoes are common in Chile.

Chile also borders the ring of fire and hosts a large number of volcanoes, some of them very active like Villarrica and Mount Hudson. “Actually, what we're seeing at the point where the three plates meet is an opening process—a rift—so volcanic or magmatic material could rise there,” said geologist Fabien Bourlon, according to an interview in the Science article “Dams for Patagonia.” He further explained: “there's a volcanic gap at the dam sites. A line of volcanoes stops north of the site at Chaltén, and then there are none until Hudsen to the south. So it's likely there's an undiscovered volcano there.”

Given the active geology of the area, building dams there does not seem to be the brightest of ideas. If Hudsen were to erupt, large pieces of rock and debris could rupture a dam, damage its turbines, and volcanic ash could quickly silt up the reservoir. Originally, the transmission line for the project was planned to run right over Chaitén, the volcano that erupted spectacularly in May 2008, sending plumes of ash 54,000 feet (16,700 m) into the sky while burying the local village. But that's not all.

In Patagonia, glacial lakes often overrun their banks and send meltwater surging downstream; such overflows are becoming more frequent with global warming, according to the country's climate scientists. There are currently five glacial overflows in the North Patagonian ice field, with a large one spilling at the headwaters of the Baker River since 2008.

“They are preparing to construct dams on what is probably the most unstable river system on the planet,” says Brian Reid, a limnologist at CIEP in the University of Austral, Valdivia. “To what extent it is active we don't know because it's never been studied.” It is an open question whether a dam could withstand the sediments carried by a glacial lake overflow (GLOF), which can reduce a dam's life span by raising the reservoir bed and clogging generator turbines. According to Reid: “A GLOF in Iceland in 1996 deposited 1% of the world's sediment load for a year in a 12-hour period, making it the second largest river in the world during that time. ”

Within the ice filled Grimsvötn caldera in Iceland, intense geothermal activity continuously melts the ice to form a subglacial lake. which at intervals of 5 to 10 years is emptied along subglacial channels to create large floods, called jökulhlaups, on the sandur plain, Skeidararsandur, on the Icelandic south coast. The lake was last emptied in 1996, releasing a torrent 13 feet (4 m) high and 2000 feet (600 m) wide. The flood carried with it 185 million tons of silt. After the flooding, some icebergs 33 feet (10 m) high could be seen on the banks of the river where the glacier had run. The lake's water-level is presently low, but eventually it will fill and flood again.

Glacial lake flooding threatens anything in its path.

As we can see, building dams in Patagonia is fraught with hazards, from earthquakes to volcanic eruptions to overflowing glacial lakes. Throw in the areas mostly pristine ecosystems, mostly unstudied, and you can understand why ecologists and the local people are adamantly opposed to the hydro project. Companies like Home Depot have been asked to boycott Chilean goods in protest. People are getting desperate when the “good” alternative solution is to build more coal plants, even though their country has little coal of its own.

What about a third choice, a nuclear option? Reportedly, Chile is not ready for nuclear power because of legal and regulatory gaps as well as public resistance. “At the moment the country is not in a position to implement a nuclear program with the proper security standards,” Energy Minister Marcelo Tokman recently told a nuclear energy conference in the Chilean capital, Santiago. He added “there is enough time to close the gaps required (to build a reactor) by 2024.” Sadly, that may come too late to save the unique, unspoiled land that is Patagonia.

Perhaps what is needed is an international program to assist nations with implementing nuclear power—Nukes for Nature. Such a program could have saved the legendary, but now submerged, three gorges of China's Yangtze River. Among the breathtaking scenery and national treasures that project drowned was “White Crane Ridge,” where 20 fish sculptures carved into the rock served as water-level markers since the Tang Dynasty. Claimed to be the world's oldest hydrographic survey device, it also bore about 30,000 characters of Chinese poems from different dynasties, the earliest dated to 763 AD.

No dams in Patagonia.

As with all sources of energy, renewable or not, there is a price to be paid. Even pro-ecology activists have come to realize that the improbable specter of CO₂ induced global warming is less threatening to natural environments than damming rivers that still run free. While it is too late for China, where side effects from construction of the massive Three Gorges Dam continue to disrupt lives and alter the environment, Patagonia can still be saved by using coal in the interim and nuclear for the long run. And once that is done, perhaps such a program could help save the United States from its own foolish policies.

Be safe, enjoy the interglacial and stay skeptical.

[ Find out more about the impacts of all forms of energy in our new book, The Energy Gap, available on Amazon.com. ]