Paraná River

The Paraná River flows for roughly 4,880 kilometers through Brazil, Paraguay, and Argentina, making it the second-longest river in South America after the Amazon. It joins the Paraguay River, then later the Uruguay River, to create the Río de la Plata, which empties into the Atlantic Ocean. The Venetian explorer Sebastian Cabot, sailing for Spain, became the first European to navigate the river in 1526. In 2021, a drought caused water levels to drop to their lowest point in 77 years.

The river’s name comes from the Guarani language, where “para-” or “parana-” elements appear in many regional river names, meaning “river” or “sea.” Attempts to give this specific river a more precise translation, such as “kin of the sea,” have been dismissed.

The Paraná begins at the meeting of the Paranaiba and Rio Grande rivers in southern Brazil. From there, it flows southwest for about 619 kilometers to the site of the former Guaíra Falls (Sete Quedas), a series of seven cascades once compared to Iguazu Falls. These were flooded after the Itaipu Dam began operating in 1984. For the next 200 kilometers, the river forms the border between Paraguay and Brazil until it meets the Iguazu River. Upstream from that confluence, the Itaipu Dam—the world’s third-largest hydroelectric plant, after China’s Three Gorges and Baihetan dams—creates a large, shallow reservoir.

After merging with the Iguazu, the Paraná becomes the natural boundary between Paraguay and Argentina. From Encarnación, Paraguay, one can see downtown Posadas, Argentina, across the river. The river flows south for about 468 kilometers, then gradually turns west for another 820 kilometers before meeting the Paraguay River, its largest tributary. Before that confluence, the Yacyretá Dam—a joint project between Paraguay and Argentina—forms another massive reservoir, which has caused problems for low-lying areas of Encarnación, flooding parts of the city and displacing poorer residents and merchants.

From the Paraguay River junction, the Paraná turns south again for roughly 820 kilometers through Argentina, curving east near Rosario for the final stretch of less than 500 kilometers. It then merges with the Uruguay River to form the Río de la Plata, which flows into the Atlantic. Downstream from Diamante, Entre Ríos, the river splits into multiple arms, creating the Paraná Delta.

The Paraná’s drainage basin covers much of south-central South America, including all of Paraguay, much of southern Brazil, northern Argentina, and southeastern Bolivia. If the Uruguay River is counted as a tributary, the watershed also covers most of Uruguay. The volume of water reaching the Atlantic through the Río de la Plata is roughly equal to that of the Mississippi River delta. Major cities within this basin include São Paulo, Buenos Aires, Rosario, Asunción, Brasília, and La Plata.

The river and its tributaries support fishermen who rely on it for income and food. Commercially important fish like surubí and sábalo are harvested for local consumption or export. The Paraná Delta is also a top destination for bird-watching. Much of the river is navigable as part of the Paraná–Paraguay and Tietê–Paraná waterways, linking inland cities in Argentina and Paraguay to the ocean and providing deepwater ports. Large hydroelectric dams have blocked shipping to upstream cities, but their economic benefits offset this loss. The Yacyretá and Itaipu dams have made Paraguay the world’s largest exporter of hydroelectric power. Water level measurements, taken since 1904 for oceangoing ships, correlate with the sun’s solar cycle.

A dispute over navigation rights in 1966 arose partly because Argentina wanted to build a bridge across the Paraná near Asunción or further south, while Paraguay opposed it unless navigation issues were settled. Argentina also sought an agreement for a major hydroelectric facility at the Apipé Rapids. Paraguay, meanwhile, had already completed the Acaray Dam, which met the country’s energy needs for ten to fifteen years and produced a surplus for export.