The Loa River (
Spanish: Río Loa) is a U-shaped river in
Chile's northern
Antofagasta Region. At long, it is the country's longest river and the main watercourse in the
Atacama Desert.
Course
The Loa's sources are located on
Andean mountain slopes at the foot of
Miño Volcano
Miño Volcano is a symmetrical cone-shaped stratovolcano located in El Loa Province, Antofagasta Region, Chile. It lies a few kilometres northwest of Aucanquilcha volcano and at its foot originates Loa River. The major settlement in its vicinity ...
. The upper Loa basin is flanked on the west by a ridge with elevations that reach above , whereas to the east lies a volcanic chain, which separates it from endorheic basins as that of
Salar de Ascotán.
The river flows south on an elevated plateau, for about , to the
oasis
In ecology, an oasis (; ) is a fertile area of a desert or semi-desert environment'ksar''with its surrounding feeding source, the palm grove, within a relational and circulatory nomadic system.”
The location of oases has been of critical imp ...
of
Chiu Chiu
San Francisco de Chiu Chiu, or simply Chiu Chiu, is a village located about northeast of the city of Calama, in El Loa Province of Chile's northern Antofagasta Region. It lies at an elevation of above sea level, close to the confluence of the L ...
(CHEE-oo CHEE-oo). The upper courses of the river are at a considerable elevation above sea level and receive a large volume of water from the Andes, mainly of two major tributaries:
San Pedro de Inacaliri River
San Pedro de Inacaliri River, or called simply San Pedro River, is a river of Chile located in El Loa Province, Antofagasta Region. It begins at the confluence of the rivers Silala and ''Cajón'', at an elevation over 4,000 m asl.
A part of it ...
and
Salado River. The former joins the Loa near Conchi
reservoir and the latter about south of Chiu Chiu. The water of its upper course and tributaries is fresh. However the lower course, as in all the rivers of this region becomes brackish.
From Chiu Chiu, the Loa flows west and north in a great curve to
Quillagua
Quillagua is an oasis in the Tocopilla Province, in the Antofagasta Region of northern Chile. It is a part of the commune of María Elena. The Loa River is crossed by the Pan-American Highway in this area.
According to the ''Dirección Meteorol ...
(kee-YAH-gwah). After flowing for in this portion of its course and having run through the city of
Calama, the Loa receives the waters of
San Salvador River at the locality of ''Chacance''. Thence the river flows north for about to Quillagua.
From Quillagua, its dry channel turns westward again and marks the border between the regions of
Tarapacá
San Lorenzo de Tarapacá, also known simply as Tarapacá, is a town in the region of the same name in Chile.
History
The town has likely been inhabited since the 12th century, when it formed part of the Inca trail. When Spanish explorer Diego d ...
and
Antofagasta. Along its lower course, the Loa flows through a canyon, which crosses the
Chilean Coastal Range. The river reaches the
Pacific Ocean in lat. 21° 26' S., a few miles south of the old port of Huanillos (Wan-EE-yōs).
The hydrologic regime of the river basin is rain-dominated. The increase of its water volume occurs mainly in January and February, as a consequence of the phenomenon known locally as
Bolivian Winter
Bolivian may refer to:
* Something of, or related to Bolivia
** Bolivian people
** Demographics of Bolivia
** Culture of Bolivia
Bolivia is a country in South America, bordered by Brazil to the north and east, Paraguay and Argentina to the so ...
.
History
Its banks have been inhabited from early times. Evidence of this is the notable number of
geoglyphs,
petroglyph
A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions ...
s and
pictographs that are found along its course and in its upper basin.
Another indication of its rich past is the
Pukará de Lasana
Lasana is a small village located northeast of the city of Calama in the Calama province of Chile's northern Antofagasta Region. It sits along the banks of the Loa River.
Pukará de Lasana, (Quechua ''pukara'' fortress), a pre-Columbian fortress ...
.
Bridges
To the south of Conchi reservoir, the river is spanned by the
Conchi Viaduct
The Conchi viaduct, or Loa viaduct, is located on the Loa River in Chile, from Calama. It was built to carry part of the Ferrocarril de Antofagasta a Bolivia (Antofagasta & Bolivia Railway). It stands above the river and is long. When opened ...
, an old railroad bridge. It is no longer used by the
Ferrocarril de Antofagasta a Bolivia, however it still holds the notability of being, at , one of the highest bridges in Chile.
[Conchi Bridge]
Needs
This river supplies many towns with water used to raise shrimp. Lately, mining companies have been polluting this river, making the water unusable.
References
*
*This article draws partially on the
corresponding article in the
Spanish-language Wikipedia, accessed July 10, 2007.
External links
EVALUACION DE LOS RECURSOS HIDRICOS SUPERFICIALES EN LA CUENCA DEL RIO LOA
{{Authority control
Rivers of Antofagasta Region
Rivers of Tarapacá Region
Rivers of Chile