Río Negro (Argentina)

Río Negro (Spanish pronunciation: [ˈri.o ˈneɣɾo]; Black River) is the main river of Patagonia in terms of the size of its drainage basin, its associated agricultural produce and population living at its shores. In eastern Patagonia it is also the largest by flow rate. The river flows through the Argentine province of Río Negro which is named after it. Its name comes from the literal translation of the Mapuche term Curu Leuvu, although the water is more green than black. Formerly, it was also known as "river of the willows" because of the big number of weeping willows that grow along the bank. It is 635 km in length.

Negro Curú Leuvú, Río de los Sauces
Rio Negro near the mouth, seen from its northern bank, between the cities of Viedma, Río Negro and Carmen de Patagones, Buenos Aires
Map of the Río Negro drainage basin
Location
Country	Argentina
Provinces	Neuquén Río Negro Buenos Aires
Region	Patagonia
Cities	Neuquén Villa Regina
Physical characteristics
Source	Limay River
• location	Nahuel Huapi Lake, Neuquén
• coordinates	41°03′20″S 71°09′07″W
• elevation	770 m (2,530 ft)
2nd source	Neuquén River
• location	Near Laguna Fea, Neuquén
• coordinates	36°10′53″S 70°34′16″W
• elevation	2,800 m (9,200 ft)
Source confluence
• location	Neuquén, Río Negro
• coordinates	38°59′40″S 68°00′07″W
• elevation	250 m (820 ft)
Mouth	Atlantic Ocean
• location	El Cóndor, Río Negro
• coordinates	41°01′50″S 62°47′23″W
• elevation	0 m (0 ft)
Length	550 km (340 mi)
Basin size	102,000 km2 (39,000 sq mi)
Discharge
• location	Primera Angostura
• average	762.5 m3/s (26,930 cu ft/s)
• minimum	181 m3/s (6,400 cu ft/s)
• maximum	2,068 m3/s (73,000 cu ft/s)
Basin features
Tributaries
• left	Neuquén River
• right	Limay River

It originates from the junction of the Limay River and Neuquén River at the border with the Neuquén Province, and flows southeast incised through steppes to the Atlantic Ocean at 41.0223°S 62.7903°W / -41.0223; -62.7903, near El Cóndor beach resort some 30 km (19 mi) downstream from Viedma, Río Negro province's capital.

The river allows the Río Negro province to produce 70% of the pears and 72% the apples of Argentina. The main area of orchards lie in the middle and upper course of the river. About 48% of the Southern Hemisphere's pears are produced in Río Negro. Besides irrigation, the river is also source of hydroelectricity with small dams on its course. The river's lower 400 km are naviglable.

In 1604 the inland area of the river was reached by Spanish explorers departing from Buenos Aires in search of the mythical City of the Caesars. The river served briefly as a natural demarcation between "civilization" and the indigenous territories in the late 1870s and early 1880s during the Conquest of the Desert. In the 1900s Welsh settlers from Chubut were granted land in Choele Choel.

Valleys

Meander scars, oxbow lakes, and abandoned meanders in the broad flood plain of the Río Negro near Colonia Josefa. 2010 photo from ISS

The river is divided into three parts: The Alto Valle (High Valley) near the beginning of the river, Valle Medio (Medium Valley) near Choele Choel, and Valle Inferior (Lower Valley) near its end.

The river crosses the steppe plains of the province through a forest of around 3 km (1.9 mi) in the Alto Valle, and as wide as 20 km (12 mi) towards the Valle Inferior. In the dry plain it is possible to find seashells and pebble.

Alto Valle

The main cities in Alto Valle are: General Roca, Cipolletti, Cinco Saltos, followed by many others on the National Route #22. Together with San Carlos de Bariloche, this is the most prosperous part of the province. Most pear and apple plantations are at the Alto Valle, but many also at the Valle Medio.

Valle Medio

Next to Choele Choel is the Choele Choel Island, in which are Lamarque, Luis Beltrán and Pomona, all of them on National Route #250.

Besides apple and pear cultivation, tomato is also an important crop, being Lamarque the National Capital of the Tomato. Outside the valley, on the more arid lands around town such as Chimpay and Darwin, some cattle is also raised.

Valle Inferior

Although the term is not as used term as the previous two, Valle Inferior refers to Viedma and all the cities on the province's coast. Fruit is also produced but is not a primary activity. Onion is cultivated as well as some cereals. Alfalfa and maize is cultivated both for human consumption and for feeding cattle, which is the most important activity.

Name

In spite of its name of Negro ("black") the colour is more greenish than black. Nevertheless, the name is the literal translation of its aboriginal Mapuche name of Curú Leuvú. The river was also known by the name of Río de los Sauces ("River of Willows") for the abundant weeping willows along its lower course.

Regatta

The Regata del Río Negro (Black River Regatta), run in this river, is the longest kayak boat-race in the world with its 653 km (406 mi). The competition is divided in six stages and last 8 days (with two days for resting).

The categories are

• K1 men Senior
• K2 men Senior
• K2 men Junior (17 to 20 years)
• K2 women Senior
• K1 men Maxi (older than 36)
• K2 men Maxi
• Touring (open, non professional recreative category)

References

• Colbert E. Cushing, Kenneth W. Cummins, G. Wayne Minshall: River and Stream Ecosystems of the World: With a New Introduction. University of California Press 2006, ISBN 0-520-24567-9, S. 280ff (restricted online version (Google Books))

Attribution

• Williams, Glyn (1975). The desert and the dream: A study of Welsh colonization in Chubut 1865 – 1915. Cardiff: University of Wales Press. ISBN 978-0-7083-0579-9.

External links

• Upper Valley (English)
• Valle Medio (Spanish)
• El Valle (Spanish)
• Regatta's official site (English & Spanish)