Hydroelectric dams also play a massive role in Amazon deforestation, not just from the area flooded but by the settlement that they attract. Most of South America is energy poor, and rely on hydroelectric dams for the majority of their electricity, about 80% in Brazil. Dams depend on gradient to produce electricity; the Itaipu dam on the border of Brazil and Paraguay produces more electricity than any in the world. In the flat Amazon basin, however, dams such as Balbina, near Manaus in the Brazilian state of Amazonas, flooded 2,400 square kilometers to produce a relatively low 250 MW. Dams also alter water chemistry and affect fish passage, especially important in the highly biodiverse freshwater ecosystems of the Amazon basin. Endangered species such as the giant river otter are severly threatened by fragmentation of their river habitat. Finally, although dams provide clean energy, carbon emission from dams is very high, from both the vegetation inundated by reservoir and from methane emissions from sediment decomposition.
Numerous dams are under construction or planned in the Amazon basin; the most controversial has been the Belo Monte dam, partially underway on the Xingu River in the northern Brazilian Amazon of Para. The dam was proposed decades ago, but scaled back over concerns of displacement of native peoples. Although the dam would be the third largest in the world in total capacity, costs have skyrocketed. Current operations plan to minimize total flooding, restrict flooding to previously deforested land, compensate local communities, and install fish passage ladders. Another large dam is planned at Jirau, in the southern Brazil Amazon state of Rondonia, while countless others are planned in the Andes, especially Ecuador and Peru. See more about dams in the Amazon in the Economist and International Rivers.
Dams in the Amazon: The rights and wrongs of Belo Monte. The Economist. 4 May 2013. Retrieved from: www.economist.com/news/americas/21577073-having-spent-heavily-make-world….
Fearnside, P. M., & Pueyo, S. (2012). Greenhouse-gas emissions from tropical dams. Nature Climate Change, 2(6), 382-384.
Finer M., & Jenkins, C.N. (2012). Proliferation of hydroelectric dams in the Andean Amazon and implications for Andes-Amazon connectivity. PLoS ONE 7(4): e35126.
Forero, J. (2013, February 13). Hungry for energy, Brazil builds monster dams in the Amazon. NPR News. Retrieved from: http://www.npr.org/2013/02/13/171902544/hungry-for-energy-brazil-builds-….
Platt, J.R. (2014, April 29). Giant otters damned by giant hydroelectric dams. Scientific American. Retrieved from: http://blogs.scientificamerican.com/extinction-countdown/giant-otters-da….