Orinoco River Basin

The Orinoco River Basin is one the three major river basins in South America, along with the Amazon, and Parana-Rio de la Plata basin. With 2,700 km in length, the Orinoco River and its tributaries constitute a major fluvial system that drains almost the whole of the Venezuela territory and part of northern Brazil. About 75% of its waters are pluvial waters from the Amazon rain forest.

The Orinoco originates in the Guiana Highlands, near Mount Delgado Chalbaud, right on the political border between Brazil and Venezuela. Then it flows in a southeast-northwest direction, meandering as it runs. When it receives the fresh waters from its first important tributary of the left hand, the Guaviare River, it turns to the right, making a large arch. Thus, at this point, the Orinoco changes its direction and now flows northwards.

In Central Venezuela, another important river of its left hand side flows into it; the Meta River. When the Apure River joins it, the Orinoco begins to run eastwards, towards the Atlantic Ocean, into which it flows. It must be said that part of the waters from both the Meta and Apure River originates from melting snow on the Andes Mountain Range. Flowing down the mountain sides, these streams and creeks flow into one another to become the basin’s tributary rivers of the left hand side that flow across the grassy plains of Venezuela, called ‘Llanos’.

The most important rivers of the Orinoco’s right hand side are the Ventuari, Caura, and Caroni, which are entirely pluvial (rain water streams from the Amazon jungle).

Below, a map of Venezuela, showing the Orinoco River Basin, with its networks of tributaries.