Rio Baker is the largest river in Chile and, for now, it's undammed from source to sea. Its milky turquoise waters carry glacial sediments through a virgin land from an Andean lake along the east side of the northern Patagonian ice field to a frothy end in the Pacific Ocean.

But the river is carving a divide between the Chilean people deeper than the fjords, forcing them to look at issues of ideology and identity and compelling them to choose between two very different visions of the future.

Regarded as one of the last great wildernesses left on earth, northern Patagonia in Chile is the scene of a heated and sometimes violent quarrel over plans to build five hydroelectric dams that would quench Chile's growing thirst for electricity. It would be the largest energy project in the republic's history and generate between 20 percent and 30 percent of the Central Interconnected System's (SIC) power demands by 2020. It would also flood about 14,500 acres of pristine wilderness and be ringed by a 1,200-mile-long transmission line with more than 6,000 support towers.

Chile's Aysen region of Patagonia has become an ideological battleground. It's a metaphor for a nation at a crossroads of significant economic growth and the potential environmental despoliation that often occurs as countries emerge. Indeed, within eyeshot of each other are two projects that epitomize the Chilean divide: the $10 billion HidroAysen dam scheme and the proposed Patagonia National Park.

On one side is the HidroAysen venture, which would dam two of the world's wildest rivers, the Baker and the Pascua; drown a vast swath of forest; diminish whitewater rapids and waterfalls that are major ecotourism attractions; and destroy the habitat of the endangered southern Huemul deer, a treasure featured in Chile's national coat of arms.

On the other side, at the western boundary of the Baker, is the proposed Patagonia National Park, a 660,000-acre reserve currently in development by Conservacion Patagonica, an organization founded in 2000 by Kristine Tompkins, former CEO of the clothing company Patagonia Inc. This park would preserve the region as it is today and protect a vast strip of the semiarid Patagonian steppe and beech forest.

Sebastian Piñera, Chile's conservative billionaire businessman-cum-president, isn't shy about where he stands in the debate. He spearheaded the campaign to bring the dam project to fruition.

However, many Chileans feel differently. According to an Ipsos Public Affairs poll taken just before the dam project's approval in May of last year, 61 percent of Chileans opposed the project.

A Boon For A Booming Economy?

When the Chilean government approved the HidroAysen project last May, Piñera told local newspaper El Mercurio, "People deserve more protection than trees."

"We are very concerned about protecting the environment," he added, "but we are much more concerned about the health and quality of life of the Chileans."

Numerous calls and emails sent to HidroAysen for comment went unanswered, but representative Maria Irene Soto recently told GlobalPost that solar and wind simply cannot meet the electricity needs of Chile's booming economy if it continues to grow at 6 percent each year, as the government hopes it will.

"There's no mystery to it. It is either nuclear, coal or gas, or hydroelectric," Soto said.

Chile has little oil or natural gas, and building a nuclear power plant was all but ruled out after the tsunami destroyed Japan's Fukushima Daiichi facility last year, given Chile's earthquake-prone geology. Judging by the success Brazil has had with hydroelectric power -- which produces about 80 percent of that country's electricity -- the Chilean government sees few viable alternatives.

Piñera announced in January that he hopes to supply 45 percent to 50 percent of Chile's energy demand from hydroelectric power in the next two decades. Those in his camp see the proposed energy project in Aysen as a pivotal step forward for the future of Chile, a nation with a thriving economy and vast mineral wealth. With its energy-intensive mining industry needing more power and living standards improving daily, Chile must double or even triple its capacity in the next 15 years, some analysts argue.

The South American powerhouse already relies heavily on hydroelectric power for electricity, and the HidroAysen project, proposed by an Italian-Spanish company, Endesa, and a Chilean company, Colbún, would build five facilities that would generate as much as 2.75 gigawatts, or nearly one-quarter of central Chile's current capacity, within eight years. The energy would travel to Santiago over a 1,200-mile transmission line, but that has yet to be approved.

A Bit Of History

On May 9 of last year, the $10 billion HidroAysen project won approval from a Chilean government commission, despite a groundswell of opposition.

The commissioners who approved it were all political appointees of Piñera's, and the president's approval rating dived to 36 percent that month. It has since bottomed out at around 23 percent.

The OK came after a three-year environmental review of the mostly roadless region in remote southern Patagonia, where rainfall is a near constant and rivers plummet from Andean glaciers into the Pacific through green valleys and fjords. Environmentalists lashed out against a lack of transparency in the decision-making process and filed an appeal.

Last June 20, a Chilean appeals court suspended the plan to build the five dams and hydroelectric plants, temporarily halting the government's approval process for the project. The plan stood in limbo until last month, when Chile's Supreme Court rejected all claims by environmentalist groups in the appeal, effectively giving HidroAysen the green light.

If the government approves the transmission line, construction work on the project could begin in 2014, and it is expected to take about 10 years.

Patagonia Without Dams

"There is no energy supply problem facing our government," Piñera said in a January speech to electricity-sector leaders, "but if we don't make decisions today, we are condemning our country to a blackout near the end of this decade."

HidroAysen sponsored advertising last year that alarmed many Chileans, including a television commercial in which lights go out while doctors are performing an operation.

Critics dismiss this as fearmongering, pointing out that other renewable sources such as wind and solar have not been explored. But this is the heart of the debate: Can Chile do without HidroAysen's energy?

Roberto Roman, associate professor of mechanical engineering at the University of Chile, said the government's assertion that the demand for electricity in Chile will double in 10 years is simply untrue.

"In fact, it has grown at an annual rate of just 3.8 percent in the last 11 years, and any reasonable analysis shows a growth rate no greater than 4.5 percent per year," Roman said in a 10-point manifesto against the project.

Roman noted: "There are abundant renewable energy resources in both conventional territories of the SIC [the energy grid in central and southern Chile] and the SING [the grid in northern Chile] that can be utilized with much lower impact to the environment than HidroAysen: more than 4,000 megawatts in geothermal; more than 5,000 MW of wind; more than 15,000 MW in minihydro; and well more than 40,000 MW in solar. And these sources are not much more expensive than HidroAysen; some are actually cheaper and more reliable."

There is also the risk to the electrical system of relying on a single point generating energy over a single transmission line, he added.

Environmentalists in Chile are not looking for a compromise. Their campaign motto is Patagonia Sin Represas, or Patagonia Without Dams.

Tens of thousands of Chileans demonstrated with this mantra when the initial measure passed last May. It was the largest uprising the nation had seen since the fall of the dictatorship in 1990 and played out with tear gas and water cannons within view of the presidential palace.

This was just before the massive student protests that galvanized the nation. Thousands of protesters took to the streets of Santiago demanding education reforms. As the movement gained global attention, its 24-year-old leader Camila Vallejo became a folk hero and was named "Person of the Year" by the Guardian, among other publications. The dam issue was lumped into and later absorbed by Chile's greater unrest and socialist demands for change.

Juan Pablo Orrego, president of the environmental umbrella organization Ecosistemas and international coordinator of the Patagonia Sin Represas campaign, is confident that the dams will be defeated -- and he's had moderate success in the past, preventing four of six proposed megadams in Biobio in central Chile.

"We've really delayed them in terms of the process, so this is not over at all," Orrego said. "The power line will be even more controversial: It will pass eight regions, 67 counties, a number of parks and protected areas, and indigenous Mapuche land. It will also pass over at least 3,000 private properties, and we are sure this will elicit thousands of lawsuits."

According to Orrego, "If you compare the HidroAysen project with the Three Gorges Dam in China, it's not so large. But it's not a quantity issue, it's a qualitative issue."

The Grass Is Greener On The Other Side

Just a quick jaunt to the northeast from the proposed dams is Patagonia National Park, a far different vision of the future.

"Chilean Patagonia is one of the last wild places on Earth," said Nadine Lehner, Conservacion Patagonica's communications director. "Besides being breathtakingly beautiful, it offers an opportunity to practice conservation at a biologically important scale. Moreover, we have the opportunity to collaborate with the Chilean government in protecting key areas."

Although Lehner's group is working with the Chilean government to develop the park, many locals feel conflicted about it. It's under the control of the American conservationist Tompkins who, along with her husband, Douglas Tompkins, has conserved more than 2 million acres of wilderness in Chile and Argentina.

Widely appreciated for his efforts as an eco-baron, Douglas Tompkins has nonetheless stirred nationalist sentiments within Chile. It seems the idea of a rich gringo coming to South America to protect nature -- not to exploit it -- was so absurd to post-Pinochet Chileans that they suspected Tompkins  of ulterior motives.

Tompkins did have ulterior motives, but they were not what the Chileans originally thought.

The Tompkins' Patagonia National Park is modeled after the North American fashion with an ambitious array of cabins, museums, restaurants, and trails. Lehner said it's "halfway complete" and open to the public as a park-in-progress with a campground, two trails, and a restaurant that will open this season. The finished park will take another three to five years.

Conservationists are touting it as the "Yellowstone of South America." When completed, it will join the 200,000 acres that Conservacion Patagonica purchased in 2004 with 460,000 acres of adjacent national reserves.

Although none of the parkland would be directly affected by the nearby dam, Lehner said it would significantly impact the landscape.

"It's a huge part of the ecosystem of this region," she said. "Damming a river distorts it in many ways -- sediment levels, temperature, water level, and more. Those changes have implications for the surrounding system. Moreover, the transmission lines that would need to be built for the project would require clear-cutting large swaths of native forest and destroying much habitat."

For its part, HidroAysen has invested in its own idea of sustainability, supporting infrastructure projects in the region's largest town, Cochrane, training hundreds of workers and promising 150 technical university scholarships for high-school students. But Lehner and the Conservacion Patagonica team see the future differently.

"Patagonia is an iconic and wild place, which has the potential to develop a healthy, thriving economy for its small communities through a mix of conservation, ecotourism, ranching, small-scale fishing, and other activities. We don't want a purely tourism-based economy, but we want to provide an economic counterweight to destructive industrial projects such as HidroAysen."

Another Dam Problem

The snow-capped Andes, once on Santiago's horizon, are now jagged shadows in the smog. Chilean activists hope to keep their Patagonian wilderness a pristine example of the beauty of the nation beyond Santiago's city limits.

As for Piñera, he'd do best to prepare himself for more of the angry mass protests that have marked his years in power as HidroAysen heads off the drawing board.

But HidroAysen may just be the start.

If there's any indication which way the clock is ticking, it's this: Almost a year to the day after regional environmental authorities first approved the HidroAysen project, the same collection of individuals gave the go-ahead for another massive hydroelectric project in the Aysen region. Named Rio Cuervo after the river it will dam, the joint venture of Australia's Origin Energy and Xstrata Copper is part of a larger plan to build three dams with a total capacity of 1,000 MW in the region.

Chile's Supreme Court accepted an appeal from environmental groups last Friday, just days after the environmental impact assessment team gave the hydroelectric project the green light, but many see this as a small roadblock.

As lawyers, politicians, environmentalists, and businessmen tout the polarizing pros of power or preservation, the Chilean everyman waits and wonders: Who will decide what's "best" for the people?