The Belo Monte Dam (formerly known as Kararaô) is a hydroelectric dam complex on the northern part of the Xingu River in the state of Pará, Brazil. After its completion, with the installation of its 18th turbine, in November 2019, the installed capacity of the dam complex is 11,233 megawatts (MW), which makes it the second largest hydroelectric dam complex in Brazil and the fifth largest in the world by installed capacity, behind the Three Gorges Dam, Baihetan Dam and the Xiluodu Dam in China and the Brazilian-Paraguayan Itaipu Dam. Considering the oscillations of river flow, guaranteed minimum capacity generation from the Belo Monte Dam would measure 4,571 MW, 39% of its maximum capacity.

Brazil's rapid economic growth over the last decade has provoked a huge demand for new and stable sources of energy, especially to supply its growing industries. In Brazil, hydroelectric power plants produce over 66% of the electrical energy. The Government has decided to construct new hydroelectric dams to guarantee national energy security. However, there was opposition both within Brazil and among the international community to the project's potential construction regarding its economic viability, the generation efficiency of the dams and in particular its impacts on the region's people and environment. In addition, critics worry that the construction of the Belo Monte Dam could make the construction of other dams upstream, which could have greater impacts, more viable.

Plans for the dam began in 1975 but were soon shelved due to controversy; they were later revitalized in the late 1990s. In the 2000s, the dam was redesigned, but faced renewed controversy and controversial impact assessments were carried out. On 26 August 2010, a contract was signed with Norte Energia to construct the dam once the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) had issued an installation license. A partial installation license was granted on 26 January 2011 and a full license to construct the dam was issued on 1 June 2011. The licensing process and the dam's construction have been mired in federal court battles; the current ruling is that construction is allowed, because the license is based on five different environmental technical reportsVIEIRA, Isabel (2011). "Diretora do Ibama diz que licença para Belo Monte teve por base cinco pareceres técnicos" |language= Portuguese. Agência Brasil, 31 January 2011 and in accordance with the RIMA (Environmental Impact Report, EIA-RIMA) study for Belo Monte.RIMA (2009). "Relatório de Impacto Ambiental do Aproveitamento Hidrelétrico Belo Monte" . Eletrobrás. May/2009.

The first turbines went online on 5 May 2016. As of October 2019 all turbines at Pimental and 17 turbines in main power powerhouse are online with total installed capacity of 10,388.87 MW at Belo Monte site, totaling 10,621.97 with the Pimental site. The power station was completed in November 2019.

History Plans for what would eventually be called the Belo Monte Dam Complex began in 1975 during Brazil's military dictatorship, when Eletronorte contracted the Consórcio Nacional de Engenheiros Consultores (CNEC) to realize a hydrographic study to locate potential sites for a hydroelectric project on the Xingu River. CNEC completed its study in 1979 and identified the possibility of constructing five dams on the Xingu River and one dam on the Iriri River.

Original plans for the project, based on the 1979 study, included two dams close to Belo Monte. These were: Kararaô (called Belo Monte after 1989), Babaquara (called Altamira after 1998), which was the next upstream. Four other dams were planned upstream as well and they include the Ipixuna, Kakraimoro, Iriri and Jarina. The project was part of Eletrobras' "2010 Plan" which included 297 dams that were to be constructed in Brazil by 2010. The plan was leaked early and officially released in December 1987 to an antagonistic public. The plan had Belo Monte to be constructed by 2000 and Altamira by 2005. Such a speedy timetable was due to the belief that Brazil's relatively new environmental regulations could not stop large projects. The government offered little transparency to the people who would be affected regarding its plans for the hydroelectric project, provoking indigenous tribes of the region to organize what they called the I Encontro das Nações Indígenas do Xingu (First Encounter of the Indigenous Nations of the Xingu) or the "Altamira Gathering", in 1989. The encounter, symbolized by the indigenous woman leader Tuíra holding her machete against the face of then-engineer José Antonio Muniz Lopes, sparked enormous repercussions both in Brazil and internationally over the plans for the six dams. As a result, the five dams above Belo Monte were removed from planning and Kararaô was renamed to Belo Monte at the request of the people of that tribe. Eletronorte also stated they would "resurvey the fall", meaning resurvey the dams on the river.

Redesign Between 1989 and 2002, the Belo Monte project was redesigned. The reservoir's surface area was reduced from to by moving the dam further upstream. The main rationale for this was to reduce flooding of the Bacajá Indigenous Area. In 1998, the Babaquara Dam was again placed into planning but under a new name, the Altamira Dam. This surprised local leaders as they felt plans for the dams above Belo Monte were cancelled. Some officials in Brazil were determined to build a dam on a river with an average flow of and at a site that offers a drop. One engineer said of the dam: "God only makes a place like Belo Monte once in a while. This place was made for a dam." President of Eletronorte, José Muniz Lopes, in an interview with the newspaper O Liberal (Belo Monte entusiasma an Eletronorte por Sônia Zaghetto, 15 July 2001), affirmed: "Within the electric sector's planning for the period 2010/2020, we’re looking at three dams – Marabá (Tocantins river), Altamira (previously called Babaquara, Xingu River) and Itaituba (São Luís do Tapajós). Some journalists say that we are not talking about these dams because we’re trying to hide them. It’s just that their time has not yet come. We’re now asking for authorization to intensify our studies for these dams. Brazil would greatly benefit if we could follow Belo Monte with Marabá, then Altamira and Itaituba."

Second study In 2002, Eletronorte presented a new environmental impact assessment for the Belo Monte Dam Complex, which presented three alternatives. Alternative A included the six original dams planned in 1975. Alternative B included a reduction to four dams, dropping Jarina and Iriri. Alternative C included a reduction to Belo Monte only. The new environmental impact assessment contained reductions in reservoir size and the introduction of a run-of-the-river model, in contrast to the large reservoirs characteristic of the 1975 plans.

Also in 2002, Workers' Party leader Luiz Inácio Lula da Silva earned a victory in his campaign for president, having originally run unsuccessful campaigns in 1989, 1994 and 1998. Lula soon brokered political deals with the center and right-wing sectors in 2003, especially with ex-president José Sarney of the state of Maranhão of the PMDB, which would set the precedent that eventually characterized the two Lula administrations: cooperation between the market and the state, a combination of a free market economy with larger social spending and welfare. This economic model provided the rationale and financial support for new efforts to construct Belo Monte. In 2007, at the beginning of Lula's second term in office, a new national investment program was introduced: the Programa de Aceleração do Crescimento (Program to Accelerate Growth). The Belo Monte Dam Complex figured as an anchor project of the new investment plan.

In 2008, another new environmental impact assessment was written, this time by Eletrobras with the participation of Odebrecht, Camargo Corrêa, and Andrade Gutierrez, which formally accepted Alternative C or the construction only of the Belo Monte dam itself. The assessment also presented further design changes; in order to avoid inundating indigenous territory, which is not permitted by the Brazilian Constitution, the new design included two canals to divert the water away from indigenous territories and into a reservoir called the Reservatorio dos Canais (Canals Reservoir). An additional reservoir would be created called the Reservatorio da Calha do Xingu (Xingu Riverbed Reservoir), and electricity would be generated from the two reservoirs using three dams: a complementary powerhouse called Pimental (233 MW), a complementary spillway called Bela Vista, and the main powerhouse called Belo Monte (11,000 MW). The Reservatorio dos Canais would be retained by over a dozen large dikes, and water from the reservoirs would be channeled towards the main powerhouse.

However, transparency of the government's plans once again became an issue, sparking indigenous tribes of the region to organize another large meeting, called the Segundo Encontro dos Povos do Xingu (the Second Encounter of the Peoples of the Xingu) in the city of Altamira, Pará on 20 May 2008.

First license granted In February 2010, Brazilian environmental agency IBAMA granted a provisional environmental license, one of three licenses required by Brazilian legislation for development projects. The provisional license approved the 2008 environmental impact assessment and permitted the project auction to take place in April 2010.

In April 2010, Odebrecht, Camargo Corrêa, and CPFL Energia dropped out of the project tender, arguing that the artificially low price of the auction (R$83/US$47) set by the government was not viable for economic returns on investment. On 20 April 2010, the Norte Energia consortium won the project auction by bidding at R$77.97/MWh, almost 6% below the price ceiling of R$83/MWh. After the auction, local leaders around the project site warned of imminent violence. Kayapó leader Raoni Metuktire stated: "There will be a war so the white man cannot interfere in our lands again." Canadian film director James Cameron also visited the site prior to the auction and stated he would produce an anti-Belo Monte Dam film called Message From Pandora which was later released in November.

In April 2010 the Brazilian Federal Attorney General's Office suspended the project tender and annulled the provisional environmental license on claims of unconstitutionality. Specifically, Article 176 of the Federal Constitution states that federal law must determine the conditions of mineral and hydroelectric extraction when these activities take place in indigenous peoples' territories, as is the case for the "Big Bend" (Volta Grande) region. As a result, the electric utility ANEEL canceled the project auction. The same day, the appellate court for Region 1 disenfranchised the Attorney General's suspension, reinstating the project auction at ANEEL.