The Paraguay and Paraná Rivers
Map of passes studied for engineering works as part of hidrovia
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The Paraguay and Paraná Rivers are the principal watercourses of what is termed the La Plata River basin, South America’s second largest after the Amazon (2,800,000 km²), flowing through Brazil, Bolivia, Paraguay, Argentina, and Uruguay. The Paraná is born in highlands in eastern Brazil, while the Paraguay flows from Mato Grosso and the Chaco region. The Paraná flows 4,695 km. (nearly 3,000 miles), emptying in the La Plata estuary near Buenos Aires and Montevideo.
There are 130 dams of more than 10 meters in height in the Paraná basin, affecting the Paraná and its tributaries (the Grande, Paranaíba, Tiete, Paranapanema, and Iguaçu). By contrast, the Paraguay has no dams, and is the central artery of the Pantanal, the world’s largest tropical wetlands ecosystem.
Principal threats to the Paraguay–Paraná system are plans by the governments of the region to channelize 2,100 miles of the rivers for an industrial waterway, or hidrovia to lower the cost of exporting soybeans, and plans for new hydroelectric dams, including the Corpus Christi dam on the Paraná River (Argentina/Paraguay), Garabí dam on the Uruguay river (Argentina/Brazil), and the raising of the Yacyretá dam reservoir (Argentina/Paraguay) to its final design level.