Brazil’s Regional Federal Tribunal (TRF1) upheld an earlier decision that declared the Brazilian Congress’s authorization of the project in 2005 to be illegal. The decision concludes that the Brazilian Constitution and ILO Convention 169, to which Brazil is party, require that Congress can only authorize the use of water resources for hydroelectric projects after an independent assessment of environmental impacts and subsequent consultations with affected indigenous peoples.

Project developers Norte Energia now have the option to appeal the decision.

The Belo Monte Dam, located on Xingu River Basin, will have an installed capacity of 11,233MW. The project was given its final environmental licence in June 2011 by the country’s environmental agency Ibama.