Construction on Chile's largest hydroelectric initiative, the 2,750-MW HidroAysén project, is awaiting final approval by the country's environmental agency, which is expected to respond by next month.

HidroAysén—a joint venture between Chilean power utilities Empresa Nacional de Electricidad SA and Colbun SA—submitted its environmental impact assessment on April 15. A decision by the Chilean government on the environmental license for the project is expected in May.

HidroAysén involves construction of five powerplants with an installed capacity of 2,750 MW; the project is located on the Baker and Pascua rivers in the Aysén region of Chile.

Transporting the power from Patagonia to the country's urban center would require construction of a 2,300-kilometer-long transmission line. Approval of the power lines is expected to be a serious hurdle and much of the environmental opposition to HidroAysén has focused on the transmission component.

Cost estimates for the project are $3.2 billion for the dams and $2 billion for the power lines. If approved, construction is slated to begin by the end of 2014 and be completed within five years.