The world’s fourth largest continent, South America is largely surrounded by water in the forms of the Caribbean Sea, and the Atlantic and Pacific Oceans. It also has a plentiful supply of freshwater, being the home of some of the world’s most magnificent rivers.
These major waterways tend to be found east of the Andes, and empty into the Atlantic. What’s more, the major river systems of The Amazon – Río de la Plata, Orinoco, and São Francisco – drain two-thirds of the continent.
Some of the longest rivers of South America form part of these wider systems, but in this article, we’re looking at the rivers proper. We’ll be identifying South America’s longest rivers, beginning with the biggest one of all.
The Amazon: The Biggest River in South America
Length: 4,345 miles
Rising in the Andes, it flows for 4,345 miles, easily making it South America’s longest river. When it reaches the Atlantic, it deposits some 7,381,000 cubic feet of freshwater every single second, meaning it’s also the biggest river in South America by discharge. In fact, one would struggle to find any parameters by which the mighty Amazon River does not surpass almost every other one on the planet. It’s second to the Nile as the world’s longest river, but even here the Amazon’s river basin – at nearly 2.7 million square miles – dwarfs the Nile’s 1.29 million square miles.
It seems that everything about the Amazon is on a vast scale, including its vital role within the rainforest that shares its name. The Amazon Rainforest, which itself covers around 40% of the continent, relies on the largest river in South America to support the several-million species that call it home. Many of these species are not found anywhere else on earth and new ones are being discovered all the time. From sloths to jaguars to more than fifty piranha species, the Amazon and its river are vital to the biodiversity of the planet.
Length: 3,030 miles
The second biggest river in South America, the Paraná, stretches over 3,000 miles from its source in Brazil, through Paraguay and finally to its mouth in Argentina. There, it joins the Paraguay and Uruguay rivers, forming the Río de la Plata estuary before emptying into the Atlantic. Along the way, it flows through a diverse landscape of rainforests, swamps, and grasslands, making it one of the most biodiverse river systems in the world.
The menacing Piranha fish is just one of many aquatic species found within the Paraná River. Its ecosystem is home to a wide variety of fish, reptiles, mammals, and birds, including endangered ones such as jaguars and seven-coloured tanager birds. The river’s floodplains are also important breeding grounds for many of these animals.
Like many of the longest rivers of South America, the Paraná has several large dams, producing hydroelectricity for the surrounding region.
Length: 2,040 miles
In addition to being one of the longest rivers in South America, the Jurua is one of the world’s wonkiest waterways. Rising in Peru’s Ucayali region, it enters the Brazilian state of Amazonas, where it becomes one of over a thousand tributaries of the Amazon River.
In all, the Jurua River basin covers an area of approximately 73,581 square miles and is incredibly biodiverse. Part of its basin is protected as a wetland of international importance and counts amongst its residents the six-tubercled Amazon river turtle, the giant anteater and almost 400 fish species.
Length: 1,995 miles
The Purús River shares many similarities with the Jurua. Both rise in Peru and flow through Brazil, both are major tributaries of the Amazon, and both are exceptionally meandering. And of course, both rank amongst the longest rivers of South America. The Purus spends most of its 1,995-mile journey meandering through Brazil, including a short stretch in the Acre region that forms the boundary between the two countries.
The Purus River basin is home to a variety of different species of plants and animals, many of which are found nowhere else on Earth. Amongst these are the Purus Tiger Pleco and the Purús red howler monkey.
Length: 1,811 miles
Located entirely in eastern Brazil, the São Francisco River is the largest river entirely within its borders as well as one of South America’s longest rivers. Beginning in the Canastra Mountains, it travels approximately 1,811 miles across five states until it reaches its mouth at the Atlantic Ocean. The climate within its 243,700-square-mile basin is among the driest in Brazil.
Among the many roles played by the São Francisco River, it is an important source of food, irrigation and electricity through its many dams.
South America's Longest Rivers
As we’ve seen, the longest rivers in South America cover some of the world’s most biodiverse regions. Indeed, the largest river in South America, the Amazon, supports one of its most important natural wonders.