It could be argued that no Chilean investment project ever has caused as much controversy as HidroAysén, a plan to build five hydroelectric plants on southern Chile’s highly prized Baker and Pascua rivers at a cost of US$10 billion. A year ago, in the weeks immediately following environmental approval of the project by Aysén region officials, protests involving tens of thousands of people at a time choked downtown Santiago, belying the image of Chileans as apathetic when it comes to environmental matters.