Chilean planners say the five-dam HidroAysen electricity generation complex is crucial to the country meeting its future energy needs but green groups argue the potential damage to Patagonian ecology will far outweigh advantages of the project.
Environmental scientists warn Patagonia's ecology will suffer irreversible damage if the dams are built as planned.
Patagonia spans Chile and Argentina and covers most of southernmost Latin America. Human habitation in the area dates to the 13th millennium B.C. but the dams are most likely to affect fauna and flora not seen elsewhere.
The HidroAysen project proposes the construction of five hydroelectric power stations, two on the Baker River and three on the Pascua River, with an average annual energy production of 18,430 gigawatt hours.
Campaigners allege corrupt politics at work in various stages of the project. Italian ecological campaigners backing Chilean groups are unhappy about what they see as suspect links between Empresa Nacional de Electricidad S.A., the Spanish power company and its owner, Italian utility company Enel.
Endesa is funding 49 percent of the project but is partially controlled by Enel, 30 percent of which is owned by the Italian government. Italian campaigners oppose Italian taxpayers' money going into the controversial project.
They are backed by Chilean non-government organizations Ecosistemas and Aysen Citizens Coalition to Preserve Life, plus mayors of cities and towns in the region.
Last month protests against the project spread to the capital, Santiago, and Puerto Montt, a key harbor in the southern region.
The Italian and Chilean environmentalist groups are backed by Chilean Patagonia Sin Represas, a campaign group that supports a Patagonia without dams and has opposed large hydroelectric projects in the area.
The group said it will continue to pressure Italian organizations not to join the project. Campaign groups warned the arrival of thousands of workers in the area could destabilize the region. Flooding and creation of large water reservoirs could alter ecology to Chile's detriment, the critics said.
Campaigners say the plan doesn't value Patagonia as the unique resource that it is, ignoring the irrevocable damage the dams and the power lines will do to the pristine conditions of the place and the wildlife.
The Tourism Service objected, too, stating the dams' profound impact on the landscape will affect tourism throughout Patagonia and not just the Aysen Region.
Experts also warned sufficient research hasn't been done to establish the effects of climate change on Patagonia's glaciers, which are documented to be melting at alarmingly rates.