Hydropower in the Pan Amazon: Belo Monte and the Río Xingu

  • Mongabay has begun publishing a new edition of the book, “A Perfect Storm in the Amazon,” in short installments and in three languages: Spanish, English and Portuguese.
  • Author Timothy J. Killeen is an academic and expert who, since the 1980s, has studied the rainforests of Brazil and Bolivia, where he lived for more than 35 years.
  • Chronicling the efforts of nine Amazonian countries to curb deforestation, this edition provides an overview of the topics most relevant to the conservation of the region’s biodiversity, ecosystem services and Indigenous cultures, as well as a description of the conventional and sustainable development models that are vying for space within the regional economy.
  • Click the “A Perfect Storm in the Amazon” link atop this page to see chapters 1-13 as they are published during 2023.

The most controversial hydropower project in the Pan Amazon is the complex on the Rio Xingu near the city of Altamira (Pará). The proposal to build a dam on the Rio Xingu dates from 1979 and, as originally conceived, consisted of a cascade of multiple dams located at different points along the 2,500-kilometre river. Opposition by Indigenous groups, academics and civil society held up the project for decades and caused the government to develop, propose and modify multiple iterations of a constellation of dams, reservoirs and power plants.

In 1987, the government proposed a configuration composed of five D&R units that would have flooded more than 1.7 million hectares of forest and the installation of 24 GW of generating capacity. This proposal was doomed because it would have flooded hundreds of thousands of hectares of forest within Indigenous territories, which were being formally constituted following the constitutional reforms of 1988. The international attention caused by the Encontro das Nações Indígenas do Xingu in 1989 forced Electronorte to abandon four of the five proposed sites.

Nonetheless, the company insisted on building the lowest dam on the river, which had the greatest energy potential due to the volume of water and an elevational drop of more than 100 meters. Coincidentally, it was located at a spectacular set of rapids, where the Xingu flows off the Brazilian Shield onto the flood plain of the Lower Amazon, known as the rapids of the Volte Grande.

The Belo Monte hydropower facility generated enormous civil and legal conflicts was redesigned from a dam-and-reservoir model to a run-of-the-river system to avoid some of the impacts linked to water impoundment. Source: NASA Earth Observatory, https://earthobservatory.nasa.gov/images/91083/reshaping-the-xingu-river

The revised project still provoked fierce opposition from domestic and international groups, as well as technical observations by the environmental protection agency (IBAMA), which were translated into legal petitions filed by the environmental division of the public prosecutor’s office. The resistance to the dam was organized by the Kayapó, an Indigenous nation led by a particularly astute set of tribal leaders. The government planners changed the name of the facility from Kararaõ, the name of a Kayapó tribe, to Belo Monte, the name of the village at the bottom of the Volta Grande.

The final version of the Belo Monte hydropower facility is an unusual two-stage D&R facility: an upper dam (Pimental) that diverts water via a canal to the lower dam and power plants (Belo Monte). The two dams jointly flood 51,600 hectares, of which 38,000 are located on the floodplain above the Pimental dam. An important aspect of the final design was the determination to maintain (reduced) water flow in the Volte Grande, a measure intended to mitigate the impact on the livelihoods of the Indigenous communities residing between the upper and lower dams.

The final scaled-down version of the project was proposed during the administration of Fernando Cardoso and was enthusiastically embraced in 2002 by President Lula da Silva, who, as leader of the workers’ party, was attracted by the opportunity to create 50,000 direct and indirect jobs. Construction started in 2011 and the first of eighteen turbines was inaugurated in 2016 during the administration of Dilma Rousseff. Jair Bolsonaro celebrated the completion of the project in 2019.

The Belo Monte hydropower complex houses 18 turbines with an installed capacity of 11.2 GW. Credit: PAC collection at flickr.com; CC BY-NC-SA 2.0.

The Usina Hidrelétrica de Belo Monte became a reality because it had the support of a popular president and his allies in Congress, and the backing of powerful economic interests. It was built by a consortium of construction companies, all of whom would become ensnared in the Lavo Jato scandal. The dam and associated infrastructure are operated by Norte Energia, a consortium of energy utilities, mining companies and pension funds Most of the energy generated from the unit will be consumed in Southeastern Brazil via two HVDC transmission lines built by an energy conglomerate from China.

The original estimate for the construction of the entire facility was estimated at R$ 16 billion in 2010, but the final bill is estimated to be about R$ 40 billion in 2020. The total cost is difficult to know due to the complex nature of the contracts and cost overruns that characterize hydropower projects. Converting those numbers into dollars is problematic because the Brazilian Real (R$) lost ~70% of its nominal value when compared to the US dollar over the same period.

In spite of its design to minimize upstream impacts, the dam has drastically curtailed the extent, duration and timing of annual floods in the seasonally inundated forests below the dam, which has changed the ecological functionality of key habitat that supports the river’s commercial fisheries. Biologists are particularly concerned about how modified water flows will impact the Tabuleiro do Embauba, a beach located just below the dam where tens of thousands of endangered Giant Amazon River Turtles (Podocnemis expansa) congregate annually during the breeding season.

A nesting beach used by the Giant Amazon River Turtle (Podocnemis expansa). The reservoirs created by Tapajós Basin dams will flood hundreds of square miles, and radically alter the flow of water within the river systems. Aquatic and floodplain habitats will be altered and destroyed, including nesting beaches such as this one. Photo by Camila Ferrara.

A dramatic example of the biological impact of the dam occurred when operators diverted water to the hydropower facility in 2012. Water flow through the Volte Grande was reduced by eighty per cent and provoked the death of sixteen million tonnes of fish from oxygen starvation when they were stranded in isolated pools in the main channel. A $US 1 billion fund was supposed to compensate the local communities for these impacts, but legal disputes and administrative inefficiencies impeded its disbursement, and the communities were forced to manage what presumably was a foreseen impact without the assistance they had been promised in the environmental action plan.

Unfortunately, the hydraulic models used in the design of the complex two-stage facility failed to take into account the impact of periodic droughts and, in 2019, reduced water flows forced operators to shut down all but one of its eighteen turbines. In late 2020, the environmental protection agency (IBAMA) ordered the company to increase water flows through the Volte Grande, which placed it in danger of defaulting on its energy supply obligations. If this situation recurs or becomes a chronic event, the financial viability of the entire enterprise will be compromised. The loss of electricity from Belo Monte would cause an energy deficit in the national grid that would be particularly serious in the Southeast and Centre West regions of the country.

“A Perfect Storm in the Amazon” is a book by Timothy Killeen and contains the author’s viewpoints and analysis. The second edition was published by The White Horse in 2021, under the terms of a Creative Commons license (CC BY 4.0 license).

Read the other excerpted portions of chapter 2 here:

Chapter 2. Infrastructure defines the future