Río de la Plata: Estuary and Drainage Basin (Argentina, Uruguay)
Río de la Plata is a tapering intrusion of the Atlantic Ocean on the east coast of South America between Uruguay to the north and Argentina to the south. The Brazilian Highlands, the Andes Mountains, and Patagonia bound the Río de La Plata drainage basin.
Río de la Plata
Estuary
Río de la Plata is a tapering intrusion of the Atlantic Ocean on the east coast of South America between Uruguay to the north and Argentina to the south. It empties into the Atlantic Ocean, forming a funnel-shaped indentation on the southeastern coastline of South America. It forms part of the border between Argentina and Uruguay.
While some geographers regard it as a gulf or as a marginal sea of the Atlantic Ocean, and others consider it to be a river, it is usually held to be the estuary of the Paraná River and Uruguay River (as well as of the Paraguay River, which drains into the Paraná).
To those who regard the Río de la Plata as a river, it is the widest in the world, with a total area of about 35,000 sq km (13,500 sq mi).
![Map of the Río de la Plata, River Plate or [La] Plata River, between Argentina and Uruguay in South America](/sites/default/files/inline-images/plata_buenos_aires_montevideo_map_opt%20%281%29.png)
Map depicting the Río de la Plata, between Argentina and Uruguay in South America
Drainage Basin
The Río de la Plata basin is a 3,170,000 sq km (1,220,000 sq mi) hydrographical area that drains into the Río de la Plata. The La Plata River drainage basin is bounded by the Brazilian Highlands to the north, the Andes Mountains to the west, and Patagonia to the south.
The basin region includes areas of southeastern Bolivia, southern and central Brazil, the entire country of Paraguay, most of Uruguay, and northern Argentina. Making up about one-fourth of the continent's surface, it is the second-largest drainage basin in South America (after the Amazon basin) and one of the largest in the world.
The main rivers of the La Plata basin are the Paraná River, the Paraguay River (the Paraná's main tributary), and the Uruguay River.
The Paraná River's main tributaries include the Paranaíba River, Grande River, Tietê River, Paranapanema River, Iguazu River, Paraguay River, and the Salado River, which ends in the large Paraná Delta.
The Paraguay River flows through the Pantanal wetland, after which its main tributaries include the Pilcomayo River and the Bermejo River before it ends in the Paraná.
The Uruguay River's main tributaries include the Pelotas River, Canoas River, Ibicuí River, and the Río Negro. Another significant tributary to the Río de la Plata is the Salado del Sur River.
Several hydroelectric dams are operating in the basin; among them, the second largest operating facility in the world, Itaipu, is shared between Paraguay and Brazil on the Paraná River.

Map showing the Río de la Plata drainage basin, including major tributaries and cities
The plant life within the vast Río de la Plata region is diversified. To the east in the upper Paraná basin and higher elevations are forests with evergreens like the Paraná pine tree. The western region is mainly grassland used for cattle grazing.
Plants in flooded areas thrive in wetlands, such as the water hyacinth, Amazon water lily, trumpetwood, and guama. Along the rivers and streams are palms such as the murti, the carandá and various species of quebracho trees.
In the Gran Chaco, the western region of Paraguay, where the land is used mainly for cattle raising, are clusters of trees, bushes, herbaceous savannas, and drought-tolerant thorny shrubs.
Throughout eastern Paraguay are lapacho trees and the evergreen shrubs (llex paraguariensis) whose leaves make yerba maté, a stimulating tea-like beverage popular in many South American countries.
The Río de la Plata is a habitat for the loggerhead sea turtle, green sea turtle, leatherback sea turtle, the rare La Plata dolphin, and many species of fish, which include catfish, surubí, manduva, patí, pacu, corbina, pejerrey, meat-eating piranha, and the most prized species, the dorado, which resembles a salmon.
There is also an abundance of reptiles throughout the region, such as two caiman species, iguana lizards, rattlesnakes, water boas, yararás, frogs, toads, and freshwater crabs. The area is also populated with numerous game birds, herons, and storks.