quirk that infused the Baker River system with unique biodiversity. Unlike rivers to its north and south, the Baker contains an endemic population of fish, such as members of a primitive catfish genus and Odentethes hatcheri, a type of silverside.
Dams on the Baker will prevent fish migration, and even the subtle alteration of nutrients can have far-reaching effects, says Brian Reid, an energetic American limnologist (someone that studies fresh waters), who we visit at the Patagonia Ecosystem Research Centre in Coyhaique. ‘Damming a river turns it into a lake and completely alters its function,’ he explains. Brian is interested in the river’s silica levels, which are an important component of diatoms, a major group of planktonic algae that support a large ecosystem. If the levels of silica go down compared to the levels of nitrates, another group of algae called flagellates are favoured, which are responsible for toxic oceanic ‘red tides’. Diatoms are larger than flagellates, so animals can feed on them more efficiently, making the whole system more productive.
Brian fears that dams on the Baker River could significantly alter the silica levels downstream. ‘Damming of catchments across Europe has resulted in so much particulate trapping that it has reduced silica levels in the Baltic and Black seas. Production and efficiency of marine organisms there has gone down and it has affected fisheries.’ The head of the Baker River is a pro-glacial lake, producing significant levels of silica. ‘I row the river in a raft when I’m sampling, and you can hear the turbidity, the tiny velocities that keep everything in suspension – it sounds like a bowl of Rice Krispies,’ Brian says. If it is dammed, it will result in a warmer reservoir that would be more productive, but a loss of suspended sediments flowing to the ocean.
No system on Earth is ever truly isolated from another, which is why the human changes we make to even small parts of the planet can have such enormous consequences. Building a hydroelectric dam hundreds of kilometres inland can affect cod numbers far out at sea. In the Anthropocene, our Earth-changing capabilities are more sophisticated than ever, but we have barely begun to comprehend the complexity of our impact. Until now, this has meant that we address each eventuality as it occurs, in a cascade of reactions to each action. But, as scientists get better at modelling the outcomes of our various interventions, we should be able to fine-tune our geoengineering to benefit people and ecosystems.
The way that many hydrodams operate, for example, has an unnecessary impact on wetland ecosystems. So-called ‘hydropeaking’ – flooding and draining a reservoir in artificial daily pulses – can be devastating for fish. The dramatic rise and fall of water levels during dam releases – sometimes of several metres – is too extreme for plants and animals to cope with, resulting in dead zones around the shores of reservoirs. Fish that lay their eggs in the shallows among submerged tree roots, for example, may find a few hours later that those sites are high and dry with the eggs desiccated, sometimes with the loss of an entire species. Most dams use hydropeaking because it’s most profitable, releasing most energy at the peak of demand. A less damaging option is a run-of-river design which, instead of relying on a head of water to build up in a big reservoir behind a dam wall, simply allows natural river flow to drive the turbines. Run-of-river dams don’t disturb the upstream ecosystem because no reservoir is created, they don’t get silted up, and they don’t result in the abrupt upstream–downstream temperature difference you can get when a reservoir is drained from its lowest (coldest) layers. They are only suitable where a river has significant drop, which the Cuervo has, prompting campaigners to call for the dam company XSTRATA to change its dam plans there.
But the Cuervo plan has bigger problems. The proposed dam lies directly above the Liquiñe–Ofqui fault line, on a triple point where the Nazca, South American and Antarctic tectonic plates meet. It means that there is a likelihood of a volcano or earthquake at the site, and yet there has been no study to investigate this, Peter says. In 2007, one month after XSTRATA submitted its report declaring the siting to be on a seismically inactive zone, the area experienced a massive earthquake that dislodged boulders into the fjord below, triggering a tidal wave that killed people on the opposite bank. ‘The government threw out their report,’ Peter laughs. Earthquakes have wrought considerable damage at dam sites around the world, including in April 2010, when a quake at Yushu in China’s Qinghai province killed tens of thousands of people in minutes. The Yushu reservoir, sited on a seismic zone, may actually have triggered the quake due to the weight of the water on the underlying geology. In the Anthropocene, humanity’s dam-building is shaking the Earth.
There are other dangers too. Patagonia is one of the fastest-melting glacial regions in the world, which has already resulted in catastrophic outburst floods, debris-laden torrents carrying away entire forests. At times, these glacial floods have caused the Baker to rise by four metres and even turn around and run upstream for days at a time. ‘They are preparing to construct dams on what is probably the most unstable river system on the planet,’ Peter says, flinging his arms incredulously.
Back in town, I visit the offices of dam company HidroAysén. Veronika, an earnest and sweet-natured woman, is adamant that the dams would rescue local people from poverty by providing much-needed employment and helping development in the region. I press her on this vague ‘development’ term, and she describes how she was one of the fortunate few who escaped from her isolated village for a year’s education in Puerto Montt, a small city further north. ‘Most people here have no choices. There are not many restaurants or shopping malls or decent education opportunities,’ she says. ‘It is very difficult even to get to the next village because the roads can be very bad and impassable, especially in winter.’ Dam-building requires improvements to the roads and surrounding infrastructure, and shops, restaurants and other services will be built to serve the workers, she reasons.
Her colleague, Rodrigo, is also in favour of the dams because he sees them as the only viable energy option for Chile. In 2009, reliance on Argentinian gas led to disaster when a domestic crisis there created a fuel shortage and the country cut Chile off. ‘We can’t rely on another country to provide our energy,’ Rodrigo says. The energy-security argument is one the dam company is focusing on in an orchestrated PR campaign that includes television advertisements threatening catastrophe if the project is blocked. One shows the lights going out mid-surgery in an operating theatre.
After repeated back-and-forth between HidroAysén, XSTRATA and the government, and seven court appeals on environmental grounds, Chile’s supreme court ruled in favour of the dams in April 2012. Only the transmission line awaited approval.
But astonishingly, one by one, the project’s backers have begun pulling out, bowing to public pressure. President Piñera’s own ratings plummeted after he publicly supported the dams following massive – occasionally violent – protests against them. Chile’s second biggest bank, BBVA, announced it would not be assisting HidroAysén with loans for the project, citing environmental and social concerns. And then, in December 2012, Colbun, the big Chilean energy company, announced it was selling its 49% stake in HidroAysén. In December 2013, Chile elected the left-wing president Michelle Bachelet, who has spoken out against the dams. For the first time, the $10 billion megaproject looked on shaky ground.
The battle is far from over, though. Electricity rates on the central grid have risen by 75% in six years, straining pockets and the economy, especially in energy-intensive mining operations north of the desert. With Chile relying on copper for as much as one-third of the national income, the spectre of cheaper hydropower from the south will not vanish soon.
Unlike other megadam projects around the world, the Patagonian proposals are not primarily of humanitarian concern. But they do raise fundamental questions about what we really mean by sustainable development in the poor world, and clean energy in the Anthropocene, and what price we are willing to pay as a global community to preserve unique areas of our planet.
If the transmission line gets the go-ahead in Patagonia, electricity production could begin as early as 2015. If not, Chile will be one of the few developing countries to choose to protect its natural environment over short-term financial gain.
