The Xingu winds north through the state of Para to meet the Amazon, and along a 100-kilometer stretch called the Volta Grande, or Big Bend, the river falls roughly 87 meters through rapids, braided channels and seasonally flooded forest. Eighteen ethnic groups live along this river, more than 25,000 people in all, among them the Juruna, who call themselves Yudja, along with the Arara, the Kayapo and the Xikrin. The river's name is commonly translated as house of God. Its flood pulse sets the calendar: when water rises into the igapo forest, fruiting trees drop their seed into the shallows and the fish come to feed and spawn. Take away the pulse and you do not merely reduce a catch. Researchers working alongside these communities describe the loss as a shift in how the world itself is understood.

Plans first emerged in 1975 under Brazil's military dictatorship, when Eletronorte commissioned a study that identified five possible dam sites on the Xingu and one on the Iriri. The scheme leaked in 1987 and met an antagonistic public. The First Encounter of the Indigenous Nations of the Xingu, the 1989 gathering at which Tuira confronted Muniz Lopes, forced the five upstream dams out of the plan. Kararao, a Kayapo word, was dropped at the request of the people to whom it belonged, and the project took the name Belo Monte. Redesign work ran to 2002, shrinking the reservoir from 1,225 to 440 square kilometers and adding canals to route water around indigenous territory. One engineer put the appeal plainly: God only makes a place like Belo Monte once in a while. This place was made for a dam. The people who would have to move disagreed.

Between 2010 and 2019 the complex was built through an almost unbroken procession of federal court battles. IBAMA issued a partial installation license in January 2011 despite a FUNAI staff report warning that consultation with the Paquicamba community had been inadequate. Work stopped, resumed, stopped again. In August 2012 a federal court ordered construction halted because the affected peoples had not been consulted as the Brazilian constitution requires; the Supreme Federal Court reinstated the project within weeks. Norte Energia, the consortium behind the dam, never obtained what international law calls free, prior and informed consent from the Juruna and the Arara. The first turbines came online in May 2016, and the eighteenth and last went in during November 2019.

Roughly 20,000 people were directly displaced by the flooding, and an estimated 100,000 migrants arrived to work the construction camps, many staying on when the jobs ended. Riverbank families report thinner catches, higher fuel costs for boats navigating altered channels, and dirtier water. The Xingu holds an estimated 600 fish species with an unusually high share found nowhere else, among them the zebra pleco, whose entire known world range sits inside the stretch the dam either dried out or drowned. An independent expert review concluded that the planned flow through the Volta Grande could not maintain the river's diversity. The UN Human Rights Council has denounced Brazil's handling of the project, and the International Labour Organization found the state in violation of the Indigenous and Tribal Peoples Convention it had ratified.

By installed capacity of 11,233 megawatts, Belo Monte ranks as the fifth-largest hydroelectric complex in the world, behind China's Three Gorges and Baihetan dams, Brazil's binational Itaipu, and China's Xiluodu dam. Installed capacity is not output. Because the Xingu's flow swings hard between seasons, the guaranteed generation is about 4,571 megawatts, roughly 39 percent of the headline figure, and in drought years it has fallen far below that. The complex cost upwards of 16 billion US dollars and comprises three dams, more than a dozen dikes and two canals, each 500 meters wide and 12 kilometers long, feeding 18 Francis turbines rated at 611 megawatts apiece. Much of the electricity is routed toward Brazil's aluminum industry rather than to the people living nearest the water.

The dam runs now, and the argument has moved from whether it should exist to how much water it must let go. Norte Energia releases a reduced flow into the Volta Grande on an agreed hydrograph; the Juruna of the Paquicamba Indigenous Territory have been measuring what that flow actually does since 2014, counting fish and mapping flooded forest themselves rather than waiting for the company's figures. Their data, gathered with ribeirinho neighbors and university researchers, underpins a rival proposal, the Piracema hydrograph, which asks for an April peak high enough to flood the igapo and let the fish spawn on time. Chief Raoni Metuktire, who warned in 2010 that there will be a war so the white man cannot interfere in our lands again, has carried petitions against the project to Paris. The war he named arrived in a quieter form: a river that answers to a turbine schedule instead of the rains.