Argentina’s River Systems: A Comprehensive Look

Argentina’s River Systems

Types of River Systems

Argentina has three main types of river systems:

  • Exoreic: Rivers flow into the ocean through a main collector.
  • Endorheic: Rivers flow into inland lakes or lagoons.
  • Arreic: Water is lost through evaporation or seepage.

Rivers Flowing to the Atlantic

The rivers flowing to the Atlantic Ocean are extensive and form the most important basin, the Plata Basin. Its principal collectors are the Paraná, Uruguay, and Paraguay rivers, which converge to form the Río de la Plata. The deep soils and marshy areas are irrigated, forming estuaries and gaps.

In Patagonia, numerous rivers cross stepped plateaus. These rivers originate in the Andes Mountains and experience two periods of increased flow each year: during winter rains and spring snowmelt.

Rivers Flowing to the Pacific

Rivers flowing to the Pacific Ocean are shorter and faster-flowing. They originate in the Patagonian Andes and Tierra del Fuego. The Futaleufú Hydroelectric Complex harnesses the flow of the Futaleufú River in Chubut.

Closed Systems

Argentina has two closed (endorheic) systems:

  • Outfall Basin: This basin is temporarily endorheic. During periods of high water, the rivers can reach the sea. It includes the Jáchal, Mendoza, Diamante, Atuel, and Tunuyán rivers, which are tributaries of the Desaguadero River. These rivers are used for hydroelectric power generation and irrigation.
  • Pampean Mountain Basin: This basin is formed by the Dulce, Colorado, Belén, and several other rivers. These rivers flow into shallow lakes, which are used for hydroelectric power and irrigation.

Continental Ice and Glacial Lakes

Continental ice reserves constitute the principal freshwater reserves on the continent. Large glacial lakes, such as Perito Moreno, Upsala, and Viedma (Santa Cruz), are a predominant source of freshwater. Many lakes have been shaped by glaciers, such as Nahuel Huapi and Gutiérrez.