South America’s paddle-place river ranks third by discharge
At 2,140 kilometres the Orinoco is among South America’s longest rivers, yet its real claim is volume: about 39,000 cubic metres per second at the delta, third worldwide. The Orinoquia basin covers roughly a million square kilometres—sixty-five percent in Venezuela, thirty-five in Colombia—and its name comes from Warao words for a place to paddle.
Together with its tributaries, of which the Guaviare is the largest, the river is the main transport artery of eastern and interior Venezuela and the Colombian Llanos, and its basin supports extremely varied wildlife. Its source, at 1,047 metres on Cerro Delgado-Chalbaud near the Sierra Parima, was pinned down only in 1951 by a French-Venezuelan expedition under Frank Risquez Iribarren.
The course bends in a broad arc around the Guiana Shield in four uneven stretches. The upper river runs 286 kilometres north-west through mountains to the Guaharibos rapids. The middle section, 805 kilometres long, heads west to San Fernando de Atabapo, where the Atabapo and Guaviare join, then turns north along the Colombia-Venezuela border between granite outcrops that prevent a floodplain, reaching the Atures rapids near the Meta confluence. The lower river flows 959 kilometres north-east across a broad alluvial plain to Barrancas, and the delta, some 22,500 square kilometres and 370 kilometres across at its widest, spills into the Gulf of Paria and the Atlantic.
Columbus recorded the Atlantic mouth on 1 August 1498 on his third voyage. In the sixteenth century German expeditions under Ambrosius Ehinger probed the eastern Llanos, and Diego de Ordaz sailed upstream in 1531. Alexander von Humboldt and Aimé Bonpland explored parts of the river in April and May 1800, seeking proof that Amazon and Orinoco waters connected, and described pink river dolphins.
In 1968 a British hovercraft left Manaus, climbed the Rio Negro, crossed via the Casiquiare canal, rode the Maipures and Atures rapids and reached Port of Spain, filming a BBC programme aired in 1970. At Ciudad Bolívar the Angostura Bridge opened in 1967, and a 1,200-metre power-line crossing followed in 1981.
Source: Orinoco
