The hydrography in Argentina, is of exceptional richness. Argentina has over its territory many rivers, and also has lakes, wetlands, lagoons, ice fields and groundwater. A large number of rivers which are, for the most part, navigable, traverse the country. Some of these are extremely important in hydroelectric terms.
The most important hydrographic systems in Argentina belong to the Atlantic Slope. They are the Plata Basin and the Patagonian System. Argentina also has other water systems as endorheic basins, the slope of the Pacific and the lakes and lagoons.
You can see the complete hydrographic system on the map below:
Physical map of Argentina with the main rivers and tributaries
It comprises a total surface of 1,196,916 sq. mi. (3,100,000 km2). It is regarded as the most relevant basin of hydrography in Argentina. It has an international significance: it is made up of rivers whose source is outside the Argentine territory; besides, it represents a waterway for Argentina, Paraguay and Brazil.
The Plata basin collects water from the rivers that descend from the Puna, the Subandino System, Sierras Pameanas ,Plain Pampas and Chaco, and Mesopotamia. For further information on these areas we suggest to see, Argentina: Geographical Regions (link)
The main rivers belonging to it are: Paraná, Uruguay, Paraguay, Salado, Carcarañá, Iguazú and the Río de la Plata.
The Río de la Plata (Plata River) is 25 mi. (40 km) wide as measured at Colonia (Uruguay) and 124 mi. (200 km), as measured between the extremes of its mouth. Besides, it is the river which gives its name to the basin and to the geographical region for which it sets the east boundary.
Some examples of the Plata Basin hydrographic systems are:
One of the most outstanding examples of hydrography in Argentina, are Cataratas del Iguazú (Iguazu Falls) are located on the Iguazú River on the border between the province of Misiones, Argentina, and the Brazilian state of Parana. They are a protected area and is one of the seven natural wonders of the world.
The Iguazú River originates in Brazil.
The Yacyretá Binational Hydroelectric Dam is a hydroelectric plant on the rapids of Apipé on the Parana River, near the island of Apipé Grande and Yacyretá Ituzaingó, in the Province of Corrientes, Argentina, and the Department of Itapua, Paraguay. The Paraná River rises in Brazil and in Argentine territory covers 1710 Km.
The Salto Grande Bridge, is a rail and road bridge across the Uruguay River , and is part of Salto Grande hydroelectric complex.
Binational Hydroelectric Central Salto Grande Dam and hydroelectric plant located on the site of Ayu, in the middle reaches of the Uruguay River, about 15 km north of the cities of Salto, Uruguay; and 18 Km from Concordia, Entre Ríos, Argentina.
The Uruguay River from Brazil, runs 1170 km in Argentina and empties into the Rio de la Plata.
Embalse de Cabra Corral called General Manuel Belgrano Dam, rises in the river meeting Guachipas and Arias. The Guachipas River is the continuation of Calchaqui River born on the eastern slope of the Andes, then take the name of Pasaje o Juramento, Salado River, Paraná River and finally empties into the Río de la Plata. With its 2355 km length is probably one of the waterways, longest in Argentina and belongs to the Atlantic slope.
The Embalse de Río Tercero in Calamuchita, called Embalse Ministro Pistarini is on the Río Tercero, originates in the Pampa de Achala, Córdoba. Runs west-east direction, flows into the Paraná with the name River Carcarañá , and together with the Río Cuarto, are the only rivers of Córdoba tributaries of the Río de la Plata Basin.
The Río de la Plata, belonging to hydrography in Argentina, extends from the confluence of the Paraná and Uruguay, to an imaginary line connecting the Cape San Antonio, Argentina; with Punta del Este, Uruguay. Its length is 275 km and its estuary has 35,000 km2. The Rio de la Plata has a width of 40 km off Colonia, Uruguay; and 200 km between the end points of its mouth. It is also the name given to the basin as the geographical region to which bordered on the east.
The Río de la Plata is an estuary that empties into the Argentine sea. It is precisely called an estuary to the confluence between a river of great width and flow and the sea. Here we show you the place where the Río de la Plata meets the Atlantic Ocean:
The rivers belonging to the Atlantic Slope, which traverse Patagonia, compound this system. All of them are born in the cordillera and their flow is increased twice a year, in winter due to the rainfalls and in spring due to the snow thawing. The lowest level occurs in the fall.
For more details about climate in Argentina click in to Types of Climate in Argentina
The most important rivers of this system are: Chubut, Santa Cruz and Río Negro. Chubut, Santa Cruz and Río Negro.
An example of the Patagonian System, is the hydroelectric complex The Chocón Cerros Colorados located in the region called Comahue, which are part of the Argentine provinces of Río Negro, Neuquén, south of the provinces of Buenos Aires and La Pampa. The Hydroelectric Complex comprises the central El Chocón and Arroyito on the Limay River, about 80 km upstream of its confluence with the river Neuquén.
The Río Negro is the most important river in the Patagonia and its flow is regulated by the Chocón. Then travels through a narrow valley plateau whose average width is 15 km., at the widest part of the river is the island Choele Choel. The river empties into the Atlantic Ocean, after traveling 730 km, and not receives any tributary.
The Chubut River is born in the Andes, in the Cerro de las Carreras, near Rio Negro province. Chubut River crosses the Province of Chubut from west to east along 810 km, and flows into the Atlantic near the city of Rawson. At its confluence with the Chico River is the Florentino Ameghino dam, which benefits the towns located along its course.
The Santa Cruz River rises in Lake Argentino. Which brings its waters from Lake Viedma through the River La Leona. The water is glacial, from the melting of the glaciers of Glacier National Park home. The river has an average width of 150 m, and covers 385 km, or 543 km including its sources, from the east of Santa Cruz province up to the Atlantic Ocean, ending in a deep estuary, shared with the Chico River.
Within hydrography in Argentina, the classification of Endorheic Basin are all the rivers not flowing into the sea, the waters end within the territory through filtration or evaporation.
This basin has a great hydroelectric and irrigatory significance and is considered temporary because in times of great freshets, its waters can reach the sea.
It includes the following rivers: Jáchal, Mendoza, Tunuyán, Diamante and Atuel. The Desaguadero River is the collector.
The Agua del Toro Dam is a hydroelectric dam for irrigation and flood control on the Diamante River, in the province of Mendoza, Argentina.
The Diamante River, born from glaciers on the Maipo volcano, in the Andes on the border with Chile, and flows east before emptying into the Desaguadero River. It is a fast river, snowy regime, carries a low flow of water but at high speed.
The Atuel River is another Desaguadero River tributary that runs reaching approximately 790 Km south of the Province of Mendoza.
The Tunuyán River it is located in the province of Mendoza. Born in the Tupungato volcano in the Andes, and passes through the city of Tunuyán. Until the dike El Carrizal is the “upper Tunuyán”, and starting from there the “lower Tunuyán” runs in total 220 km to the Desaguadero River.
The Ullum Dam is located on the San Juan River in south central province of San Juan, Argentina.
The San Juan River is a permanent watercourse, glacio-product of snowmelt in the Andes. Its course is 500 km long and the longest river in the region of Cuyo and the Desaguadero River Basin.
Basin of Pampa Sierras
In hydrography in Argentina the Basin of Pampa Sierras comprises streams of great relevance, hydroelectric and for irrigation. It includes the following rivers: Salí, Primero, Segundo, Quinto and other minor rivers.
Some examples of rivers, of the Basin of Pampa Sierras.
The Dique La Viña or Embalse Ing. Luis Antonio Medina Allende, is on the river the Sauces. This river is formed on the edge of Villa Cura Brochero and Mina Clavero from the confluence of the rivers Panaholma and Mina Clavero. Both are natural water channels Traslasierra Valley, from streams of Pampa de Achala, Córdoba hills.
The San Roque Dam, collects water from the Río Primero caused by rainfall, regular magnitude, running through the valley of Punilla.
Los Molinos Dam is on the Rio Segundo, which lowers the from highest sector, of the Sierras Grandes mountains.
The rivers that cross the Puna, make up a closed basin, minor.
Also part of the river system in hydrography in Argentina, we find the Pacific Slope.
The Futaleufú Hydroelectric Complex, whose official name is Gral. San Martin, is on the Futaleufu River, Chubut province.
The Futaleufu River (also known as Grande) is a fluvial channel, fed by glacial lakes belonging to the Los Alerces National Park, in the province of Chubut, Argentina. The river crosses the Andes to Chile and flows into Lake Yelcho.
Lakes and Lagoons
All the Argentine lakes are in the Patagonia, both in the cordilleran and in the extra-cordilleran areas. Some of the cordilleran lakes are shared with Chile: General Vintter, Buenos Aires, Pueyrredón, San Martín y Fagnano; whereas the rest are exclusively under Argentine sovereignty.
The lakes of the cordilleran area, exclusive sovereignty Argentina are: Lago Argentino (1.415 km2), the biggest in Argentina; Viedma (1.088 kmz), Nahuel Huapi (550 km2) and other minor lakes.
The most important lakes from the extra-cordilleran Patagonia are: Colhué Huapi (803 km2) y el Musters (434 km’), both in Chubut Province.
The lagoons are scattered along the whole Argentine territory:
There are some of marine origin, which tend to disappear and become salt-pits and others are water collections from rainfall or thawing.