IV.

Rivers and Lakes

The rivers flowing toward the Pacific are short and small in volume because the rainfall on the western slopes of the mountains is limited. The streams to the east are long and supplied with an abundance of water from the trade winds, which deposit precipitation as they approach the mountains. These mountain streams are the source of the major headstreams of the three great river systems of South America: the Amazon, which flows through Peru and Brazil; the Orinoco of Colombia and Venezuela; and the Parana-Paraguay-Uruguay river system, which empties into the Rio de la Plata, a large marine estuary along the Atlantic coast between Uruguay and Argentina.

There are many large mountain lakes, particularly in southern Chile and Argentina. Lake Titicaca, on the Altiplano along the border between Peru and Bolivia, is the highest large navigable lake in the world. It lies in a watershed that has no outlet to the ocean. The lake covers an area of about 8,300 sq km (about 3,200 sq mi). Its surface lies 3,800 m (12,500 ft) above sea level.