A simmering row over Chile's $10 billion HidroAysen hydroelectric dam has gone to the Supreme Court after critics turned down government explanations of the project's importance for Chilean industrial and social development and chose instead to fight it out in the highest judicial battleground.

Victory isn't guaranteed. The government of President Sebastian Pinera and big business interests behind the country's power industry have thrown significant weight behind their campaign to have the multiple dams project in place despite objections.

Campaigning opponents of the project say the dam will destroy the pristine environment in Chilean Patagonia in the south of the country, displace thousands of indigenous inhabitants and decimate fauna and flora thriving in ecological systems that will no longer exist once the dam is built.

The dam project is proving to be a huge embarrassment for Pinera, who has seen his approval ratings drop in a row over teachers and students demanding educational reforms. The government approved the dam project on May 9, sparking bitter protests.

Work on the dam's preliminary construction is well under way and officials and private sector executives managing the project say they don't expect a serious obstacle to having the dam in place despite the protests.

A Chilean appeals court in Puerto Montt voted 3-1 to reject seven lawsuits brought against the dam complex. The lawsuits questioned the regularity and impartiality of a government process that promised a serious environmental review in the area affected by the dam.

Responding to the latest ruling, the Patagonia Sin Represas citizen's group said it would take the matter to the Supreme Court.

The dam project is a joint venture between Chilean energy company Colbun and the majority Spanish-owned Endesa energy company, a part of Enel. HidroAysen plans to build five dams on two of Chile's largest rivers, the Baker and Pascua, in the southern region known as Aysen.

The project involves the construction of about 1,240 miles of transmission lines to carry the energy generated by the dams to central and northern Chile. The transmission network has also been condemned by conservationists and environmental groups.

Critics say the dams project is unnecessary and Chile's additional power needs can be met by cutting waste and improving distribution of the existing electricity production.

Opponents also say the project will concentrate nearly 85 percent of Chile's central grid energy production into the control of the two large companies.