River (Spanish pronunciation: [oɾiˈnoko]) is one of
the longest rivers in
South America at 2,140 kilometres
(1,330 mi). Its drainage basin, sometimes known as the Orinoquia,
covers 880,000 square kilometres (340,000 sq mi), with
76.3 percent of it in
Venezuela and the remainder in Colombia. It
is the fourth largest river in the world by discharge volume of water.
River and its tributaries are the major transportation
system for eastern and interior
Venezuela and the llanos of Colombia.
River is extremely diverse, and hosts a wide variety of
flora and fauna.
2.1 Major rivers in the
4 Economic activity
4.1 El Florero iron mine
4.2 Tar sands
5 Eastern Venezuelan basin
6 Recreation and sports
7 See also
10 External links
Map of the Lower
Orinoco River, 1897
The mouth of the
River at the
Atlantic Ocean was documented by
Columbus on 1 August 1498, during his third voyage. Its source at
the Cerro Delgado–Chalbaud, in the Parima range, was not explored
until 1951, 453 years later. The source, near the
Venezuelan–Brazilian border, at 1,047 metres (3,435 ft) above
sea level (2°19′05″N 63°21′42″W / 2.31806°N
63.36167°W / 2.31806; -63.36167), was explored in 1951 by a joint
Orinoco Delta, and tributaries in the eastern llanos such as the
Apure and Meta, were explored in the 16th century by German
Ambrosius Ehinger and his successors. In 1531 Diego
de Ordaz, starting at the principal outlet in the delta, the Boca de
Navios, sailed up the river to the Meta. Antonio de Berrio sailed down
the Casanare to the Meta, and then down the
River and back to
Coro. In 1595, after capturing de Berrio to obtain information while
conducting an expedition to find the fabled city of El Dorado, the
Sir Walter Raleigh
Sir Walter Raleigh sailed down the river, reaching the
Alexander von Humboldt
Alexander von Humboldt explored the basin in 1800, reporting on the
pink river dolphins. He published extensively on the river's flora and
The first bridge across the
River was the
Angostura Bridge at
Ciudad Bolívar, Venezuela, completed in 1967. In 2006 a second
bridge was completed near Ciudad Guayana, Venezuela, known as the
Orinoquia Bridge.
The first powerline crossing of the
River was completed in
1981 for an 800 kV TL single span of 1,200 metres
(3,900 ft) using two towers 110 metres (360 ft) tall. In
1992, an overhead power line crossing for two 400 kV-circuits was
completed just west of Morocure (between the cities of Ciudad Bolivar
and Ciudad Guayana), north of the confluence of Routes 1 and 19.
It had three towers, and the two spans measured 2,161 metres
(7,090 ft) and 2,537 metres (8,323 ft),
The course of the
Orinoco forms a wide ellipsoidal arc, surrounding
the Guiana Shield; it is divided in four stretches of unequal length
that roughly correspond to the longitudinal zonation of a typical
Orinoco — 242 kilometres (150 mi) long, from its
headwaters to the rapids Raudales de Guaharibos, flows through
mountainous landscape in a northwesterly direction
Orinoco — 750 kilometres (470 mi) long, divided into two
sectors, the first of which ca. 480 kilometres (300 mi) long has
a general westward direction down to the confluence with the Atabapo
and Guaviare rivers at San Fernando de Atabapo; the second flows
northward, for about 270 kilometres (170 mi), along the
Venezuelan - Colombian border, flanked on both sides by the
westernmost granitic upwellings of the
Guiana Shield which impede the
development of a flood plain, to the Atures rapids near the confluence
with the Meta
River at Puerto Carreño
Orinoco — 959 kilometres (596 mi) long with a
well-developed alluvial plain, flows in a northeast direction, from
Atures rapids down to Piacoa in front of Barrancas
Delta Amacuro — 200 kilometres (120 mi) long that empties into
Gulf of Paría
Gulf of Paría and the Atlantic Ocean, a very large delta, some
22,500 km2 (8,700 sq mi) and 370 kilometres
(230 mi) at its widest.
View of the
River in Mariusa National Park (Delta Amacuro)
River at its confluence with the Caroní
River (lower left)
Rapids of the
Orinoco River, near
Puerto Ayacucho airport, Venezuela
Orinoco River, here in Amazonas State, Venezuela
Orinoco River, in Amazonas State, Venezuela
At its mouth, the
River forms a wide delta that branches off
into hundreds of rivers and waterways that flow through
41,000 km2 (16,000 sq mi) of swampy forests. In the
rainy season, the
River can swell to a breadth of 22
kilometres (14 mi) and a depth of 100 metres (330 ft).
Most of the important Venezuelan rivers are tributaries of the Orinoco
River, the largest being the Caroní, which joins it at Puerto Ordaz,
close to the
Llovizna Falls. A peculiarity of the
Orinoco river system
is the Casiquiare canal, which starts as an arm of the Orinoco, and
finds its way to the Rio Negro, a tributary of the Amazon, thus
forming a 'natural canal' between
Orinoco and Amazon.
Major rivers in the
Venezuela through the east into the Orinoco
Venezuela east into the Orinoco
Atabapo: from the
Guiana Highlands of
Venezuela north into the Orinoco
Caroní: from the
Guiana Highlands of
Venezuela north into the Orinoco
Casiquiare canal: in SE Venezuela, a distributary from the Orinoco
flowing west to the Negro River, a major affluent to the Amazon
Caura: from eastern
Venezuela (Guiana Highlands) north into the
Colombia east into the Orinoco
Colombia southeast into the Guaviare.
Meta: from Colombia, border with
Venezuela east into the Orinoco
Ventuari: from eastern
Venezuela (the Guiana Highlands) southwest into
Colombia east into the Orinoco
See also: Casiquiare canal-
River hydrographic divide
The boto and the giant otter inhabit the
River system. The
Orinoco crocodile is one of the rarest reptiles in the world. Its
range in the wild is restricted to the
More than 1000 fish species have been recorded in the river basin and
about 15% are endemic. Among the fish in the river are species
found in brackish or salt water in the
Orinoco estuary, but also many
restricted to fresh water. By far the largest orders are Characiformes
and Siluriformes, which together account for more than 80% of the
fresh water species. Some of the more famous are the black spot
piranha and the cardinal tetra. The latter species, which is important
in the aquarium industry, is also found in the Rio Negro, revealing
the connection between this river and the
Orinoco through the
Casiquiare canal. Because the Casiquiare includes both blackwater
and clear- to whitewater sections, only relatively adaptable species
are able to pass through it between the two river systems.
The river is navigable for most of its length, and dredging enables
ocean ships to go as far as Ciudad Bolívar, at the confluence of the
Caroní River, 435 kilometres (270 mi) upstream.
carry cargo as far as
Puerto Ayacucho and the Atures Rapids.
El Florero iron mine
In 1926, a Venezuelan mining inspector found one of the richest iron
ore deposits near the
Orinoco delta, south of the city of San Felix on
a mountain named El Florero. Full-scale mining of the ore deposits
began after World War II, by a conglomerate of Venezuelan firms and US
steel companies. At the start in the early 1950s, about 10,000 tons of
ore-bearing soil was mined per day.
River deposits also contain extensive tar sands in the
Orinoco oil belt, which may be a source of future oil production.
Eastern Venezuelan basin
Union of the
Orinoco with the Caroní River
Encompassing the states of Anzoategui-
Monagas states, the
Interior Range forms the northern boundary and the
Guayana Shield the
southern boundary.:155 Maturin forms the eastern subbasin and
Guarico forms the western subbasin.:156 The El Furrial oil field
was discovered in 1978, producing from late
Oligocene shallow marine
sandstones in an overthrusted foreland basin.:155
Recreation and sports
Since 1988, the local government of
Ciudad Guayana has conducted a
swim race in the rivers
Orinoco and Caroní, with up to 1,000
competitors. Since 1991, the Paso a Nado Internacional de los Rios
Orinoco–Caroní has been celebrated every year, on a Sunday close to
19 April. Worldwide, this swim-meet has grown in importance, and it
has a large number of competitors. The 26th meet was held in
Sun in the mythology of the
River at GEOnet Names Server
^ Helferich, Gerard (2004) Humboldt's Cosmos: Alexander von Humboldt
and the Latin American Journey that Changed the Way We See the World,
Gotham Books, New York, ISBN 1-59240-052-3.
^ Scott, R. (2001). In the Wake of Tacoma: Suspension Bridges and the
Quest for Aerodynamic Stability. American Society of Civil Engineers.
p. 184. ISBN 9780784470732. Retrieved 2015-04-13.
^ a b "Experience". SAE Power Lines.
^ "Critical Path" (PDF). PEI. June 2005. pp. 105–111, page 107.
Archived from the original (PDF) on 23 September 2006.
^ "Pylons of the
Orinoco High-Voltage Crossing". International
Database for Civil and Structural Engineering. Archived from the
original on 13 October 2015.
Orinoco Powerline Crossing". Skyscraper Source Media Inc. Archived
from the original on 13 October 2015.
^ "Ciudad Guayana, Venezuela : Image of the Day".
earthobservatory.nasa.gov. Retrieved 2009-10-31.
River Basin, South America. Retrieved 24 May 2014
^ Reis, R.E.; J.S. Albert; F. Di Dario; M.M. Mincarone; P. Petry; and
L.A. Rocha (2016). Fish biodiversity and conservation in South
America. Journal of Fish Biology 89(1): 12–47.
^ Hales, J., and P. Petry:
Orinoco Delta & Coastal
Drainages. Retrieved 24 May 2014.
^ Seriously Fish: Paracheirodon axelrodi, Cardinal Tetra. Retrieved 24
^ Staeck, W.; Schindler, I. (2015). "Description of a new Heros
species (Teleostei, Cichlidae) from the Rio
Orinoco drainage and notes
on Heros severus Heckel, 1840" (PDF). Bulletin of Fish Biology. 15
^ "Venezuela's Magnetic Mountain" Popular Mechanics, July 1949
^ Forero, Juan (1 June 2006). "For Venezuela, A Treasure In Oil
Sludge". The New York Times. 155 (53597). pp. C1–C6. Archived
from the original on 12 December 2016.
^ a b c Prieto, R., Valdes, G., 1992, El Furrial Oil Field, In Giant
Oil and Gas Fields of the Decade, 1978-1988, AAPG Memoir 54, Halbouty,
M.T., editor, Tulsa: American Association of Petroleum Geologists,
^ "Antecedentes y Sumario Paso a Nado Internacional de Los Rios
Orinoco/Caroni" Paso Nado Internacional de Los Rios
Orinoco y Caroní"
[Antecedents and Summary of the International Swim Meet of the Orinoco
and Caroni Rivers] (in Spanish). Archived from the original on 17
^ "26 edición Paso a Nado de Ríos
Orinoco y Caroní 2016". Roberto
Muñoz Natación Venezuela. Archived from the original on 9 November
Stark, James H. 1897. Stark's Guide-Book and History of Trinidad
including Tobago, Granada, and St. Vincent; also a trip up the Orinoco
and a description of the great Venezuelan Pitch Lake. Boston, James H.
Stark, publisher; London, Sampson Low, Marston & Company. (This
book has an excellent description of a trip up the
Orinoco as far as
Ciudad Bolívar and a detailed description of the Venezuelan Pitch
Lake situated on the western side of the Gulf of Paria opposite.)
MacKee, E.D., Nordin, C.F. and D. Perez-Hernandez (1998). "The Waters
and Sediments of the Rio
Orinoco and its major Tributaries, Venezuela
and Colombia." United States Geological Survey water-supply paper,
ISSN 0886-9308 /A-B. Washington: United States Government
Weibezahn, F.H., Haymara, A. and M.W. Lewis (1990). The
as an ecosystem. Caracas: Universidad Simon Bolivar.
Rawlins, C.B. (1999). The
Orinoco River. New York: Franklin Watts.
Wikimedia Commons has media related to
Church, George Earl (1911). "Orinoco". Encyclopædia Britannica.
20 (11th ed.). pp. 275–276.
Orinoco in a Canoe at
Project Gutenberg (Transcription of
book from 1902)
Tributaries of the Orinoco
From the Guiana Highlands