Tucuruí Dam

Construction on Phase I began on November 24, 1975. Phase I called for the construction of the main dam, its dikes, the power house, spillway and upper portion of the navigation locks. On February 1, 1977, concrete-pouring began on site and in September 1978, the river diversion began. On September 6, 1984, the reservoir began filling and 206-days later it was at normal pool. Construction was completed 3 years behind schedule on November 10, 1984. The navigation lock that is part of the dam's design was only partially completed during Phase I with only the upper portion. The construction costs were predicted to be $3.6 billion but rose to over 5.5 billion by construction's end. Including interest during construction, the total cost for Phase I was $7.5 billion. Until 1999, Phase I produced an average of 21,428 terawatt-hours (77,140 PJ) of electricity per year.[1][2]

Construction on the $1.35 billion Phase II began in June 1998. This phase called for the construction of the new power house for 11 x 375 MW (503,000 hp) Francis turbines and the completion of the navigation lock-system. The new power house is located to the left of the old one and the locks are on the north side of the dam's abutments. Phase II was expected to be completed in 2006 but is behind schedule. The second power house was completed in April 2007 but construction on the navigation locks is behind schedule.[1][2][3]

Eletrobras is a Brazilian hydroelectric power company based in Rio de Janeiro.[4] The 52% state owned electrical company generates enough energy to support about one third of Brazil's annual energy consumption.[5]

Protests to the dam's construction and continued operation have been rampant since the project was announced. While anti-dam protests result from a plethora of concerns, the chief concern of activists in this case was the displacement of individuals as a result of the dam's construction and operation. The Tucuruí Dam has displaced 32,000 people, completely wiping out some communities.[6] The dam's most infamous protestor, Dilma Ferreira Silva, was brutally assassinated on March 22, 2019. Her husband and a friend died alongside her.[7] Silva was a staunch protestor of tropical damming, working as a regional coordinator for the Movement of Dam-Affected Peoples, and spent much of her time exposing the fact that while hydroelectric power is lauded as a sustainable energy source, the Tucuruí Dam's location meant it was not environmentally friendly.

Prior to the Dam's construction, farming and mining, supported by the lands which came to be flooded by the Dam, was the main way of life for peoples like the Parakan, Asurini and ParkatÍjÍ. Before construction of the dam began a study was conducted to analyze the impact the project would have on local communities in which it was determined that 900 tons of the 1,500 tons of fish that these communities relied upon for survival would no longer be accessible. Without agency in Brazilian society, these tribes were reliant upon others to advocate for their needs. This, of course, did not occur.[8]

In 2007 a series of street demonstration organized by the Movement of Dam Affected People, Movimento dos Trabalhadores Rurais Sem Terra, and Via Campesina resulted in protestors occupying the Tucuruí plant for two days. The occupation resulted in a small win for protestors, as government officials agreed to meet with representatives if the Movement of Dam Affected People to end the protest.[9]

In 2007 Movimento dos Trabalhadores Rurais Sem Terra occupied a ranch in Piratininga, São Paulo as a protest to the destruction of lands as a result of the Tucuruí Dam's construction. Through a process referred to as grilagem (translates to land-grabbing from Portuguese), which could be compared to a more violent form of gaining squatters rights in other countries, the protestors were able to occupy the land.[9]

Cultural/heritage services are those that contribute to the success of a particular community's culture and way of life. Prior to the dam's construction, multiple indigenous groups' identity was tied to the Tocantins River area in the Brazilian state of Pará which would come to be destroyed by the dam. Since the dam's construction, a number of indigenous reserves, like those of the Parakanã, Pucuruí and Montanha have been flooded and the reserves of the Mãe Maria, Trocará, Krikati and Cana Brava have been cut through by transmission lines.[10]

While cultural/heritage services refers to the spaces humans inhabit, habitat services refers to animals. The river was once home to 280 species of fish, but only 178 species remain. Additionally, aquatic mammals, such as manatees, river dolphins, and amazon dolphins which once flourished in the region are not expected to survive spillways and other impacts the dam created, threatening the continued success of these species.[11]

Supporting services are one which help stabilize a particular ecosystem. In the wake of the dam's completion the region it inhabits underwent eutrophication, the process of soil becoming too nutrient rich, making it a breeding ground for malaria carrying mosquitos and ideal habitat for excessive aquatic plant life growth as a result.[12]

The Tocantins watershed was, historically, an important access point for freshwater amongst the humans and animals living in the region. As a result of construction, however, the water quality of the Tocantins River Basin has been jeopardized due to discharge of industrial effluents, residues of agricultural uses, and untreated sewage disposal.