A federal court in Brazil has blocked the issuing of an environmental licence for the planned 7.8 GW São Luiz do Tapajós hydroelectric plant in the Amazon region.

Judge José Airton de Aguiar Portela ruled the project did not provide an adequate appraisal of environmental impacts and failed to respect concerns of indigenous tribes. “The government cannot disregard laws that it itself implemented, irrespective of the urgency of the country’s energy demands,” commented judge Aguiar.

The decision comes after public prosecutors said the plant would adversely affect more than 10 000 indigenous residents and damage local ecosystems in the municipalities of Itaituba and Trairão, located in northern Pará state.

State-run power holding company Eletrobras and its subsidiary Eletronorte said a study had shown the project would have no negative environmental or social impacts. But the two companies will face a daily fine of 100 000 reais (US$47 700) if they flout the court’s decision.

São Luiz do Tapajós, due to begin operating in December 2017, is one of seven hydroelectric plants set to make up an 11GW mega-complex on the Tapajós and Jamanxim rivers. Eletrobras is the project’s principal stakeholder along with Eletronorte, builder Camargo Corrêa and France’s EDF.