The Amazonian city of Altamira played host to one of the more uneven contests in recent Brazilian history this week, as a colourful alliance of indigenous leaders gathered to take on the might of the state power corporation and stop the construction of an immense hydroelectric dam on a tributary of the Amazon.

    At stake are plans to flood large areas of rainforest to make way for the huge Belo Monte hydroelectric dam on the Xingu river. The government is pushing the project as a sustainable energy solution, but critics complain the environmental and social costs are too high.

    For people living beside the river, the dam will bring an end to their way of life. Thousands of homes will be submerged and changes in the local ecology will wipe out the livelihoods of many more, killing their main food sources and destroying their raw materials.

    For the 10,000 tribal indians of the Xingu, whose lives have changed little since the arrival of Europeans five centuries ago, this will be a devastating blow.

    "This is the second time we are fighting this battle," says Chief Bocaire, a young leader of the Kayapo, one of more than 600 Indians from 35 ethnic groups who gathered in record numbers in Altamira. The Indians had travelled hundreds of miles to get there in an area with hardly any roads. The roads that do exist are mostly dirt tracks, impassable in bad weather and difficult and dangerous at the best of times. For most it has been an odyssey of several weeks, travelling in small boats to reach the roads.

     "In 1989, our parents defeated a similar proposal with the help of the international media. Now it is back. But we are ready to fight again. This time we speak their language, and we are more determined than ever," says Chief Bocaire.

    With so much at stake, tensions spilled over into violence this week when an engineer from the power company Eletrobras was caught up in a melee with Indians wielding machetes. Paulo Fernando Rezende had his shirt ripped from him and was left with a deep cut to his shoulder.

    Nineteen years ago, the Indians called on the support of the rock star Sting and the late Body Shop founder Anita Roddick. Pictures of the pair alongside Chief Raoni, with his lower lip distended by a traditional lip plate, sent their message to the outside world.

    The reservoir will flood up to 6,140 square kilometres (2,371 square miles). Scientists say it will cause a dramatic increase in greenhouse-gas emissions. from the decomposition of organic matter in the stagnant water of the reservoir.

    "Hydroelectric dams have severe social impacts," Philip Fearnside, one of the world's leading rainforest scientists explains, "including flooding the lands of indigenous peoples, displacing non-indigenous residents and destroying fisheries."

    Dr Fearnside said the project helps aluminium plants looking to cash in on exports but does little for local needs, and in fact increases the health risks to local populations, including malaria.

    For three months in the dry season, the flow of the Xingu reduces to a trickle and the dam's turbines will stop working, unable to maintain the supply of power and necessitating the use of inefficient fossil-fuel power stations.

    Last November, Chief Bocaire delivered a letter to President Luis Inacio Lula da Silva. Signed by 78 leaders, the letter demanded that all dam be halted.

    But Glenn Switkes, of International Rivers, says: "The Lula government and its political allies are closing ranks to ensure it goes ahead no matter what the cost. The construction cost could be more than £5bn, and Belo Monte will not be feasible without building other dams upstream to regulate the flow of the Xingu ñ and that means facing off with the Kayapo."

All republished content that appears on Truthout has been obtained by permission or license.