San Juan River (Argentina)
Encyclopedia
The San Juan River is, together with the Jáchal
, the most important river of the Argentine
province
of San Juan
. Both join the Desaguadero
/Colorado
system that end at the Atlantic Ocean
.
The river starts near the town of Calingasta, in the southwest of the province, from the confluence of three main rivers: the Calingasta River, the Castaño Viejo River, and the Río de los Patos
. These rivers are born at an altitude of around 4,000 metres above mean sea level
in the west and southwest of the province (in contrast, the Jáchal receives its Andean
tributaries from the north of the province).
From Calingasta the river flows eastwards feeding the Quebrada de Ullum Dam
(Embalse Quebrada de Ullum) located near San Juan
city, from which it continues south-eastwards receiving a few more tributaries, including the Mendoza River
, to later join the Desaguadero River
near the Salina Pampa de las Latas (or Salina Bermejo), at the common border of the provinces of San Juan, Mendoza
and San Luis
.
The river has an average flow of 56 m³/s. Its course is 500 km long, and its drainage basin
covers an area of 39,906 km². The Ullum Dam, at 768 m AMSL, covers an area of 32 km² and has a volume of around 440 million m³. The upper course of the river is used for water sports such as rafting
and fishing
, and windsurfing
and swimming at the Ullum Dam. Along its whole length, the San Juan River is heavily used for irrigation
.
Jáchal River
The Jáchal River is a river in the province of San Juan, Argentina. It is part of the Desaguadero River basin, and one of the most important permanent watercourses in the province, with an average flow of 9 m³/s...
, the most important river of the Argentine
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
province
Provinces of Argentina
Argentina is subdivided into twenty-three provinces and one autonomous city...
of San Juan
San Juan Province (Argentina)
San Juan is a province of Argentina, located in the western part of the country. Neighbouring provinces are, moving clockwise from the north, La Rioja, San Luis and Mendoza. It borders with Chile at the west....
. Both join the Desaguadero
Desaguadero River
The Desaguadero River is the general name of a river in western Argentina that receives a number of different names on its path of 1,515 kilometres, with its most important section named Desaguadero proper.-Spring:...
/Colorado
Colorado River (Argentina)
The Colorado River is a river in the south of Argentina.The Colorado river marks most of the political limit between the provinces of Neuquén and Mendoza, and between Rio Negro and La Pampa...
system that end at the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
.
The river starts near the town of Calingasta, in the southwest of the province, from the confluence of three main rivers: the Calingasta River, the Castaño Viejo River, and the Río de los Patos
Río de los Patos
-References:* Rand McNally, The New International Atlas, 1993.*...
. These rivers are born at an altitude of around 4,000 metres above mean sea level
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
in the west and southwest of the province (in contrast, the Jáchal receives its Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
tributaries from the north of the province).
From Calingasta the river flows eastwards feeding the Quebrada de Ullum Dam
Quebrada de Ullum Dam
The Ullum Dam is a dam on the San Juan River, in Province of San Juan, Argentina. It is located at the gorge of the Quebrada de Ullum, 18 km upstream from the provincial capital San Juan, and creates a reservoir with an area of 32 km², a volume of 440 million m³, and average and maximum depths of...
(Embalse Quebrada de Ullum) located near San Juan
San Juan, Argentina
San Juan is the capital city of the Argentine province of San Juan in the Cuyo region, located in the Tulúm Valley, west of the San Juan River, at above mean sea level, with a population of around 112,000 as per the ....
city, from which it continues south-eastwards receiving a few more tributaries, including the Mendoza River
Mendoza River
The Mendoza River is a river in the province of Mendoza, Argentina. It is formed in the Andes range between the Aconcagua and the Tupungato, by the confluence of the Vacas, the Cuevas and the Tupungato Rivers, the last being its major tributary....
, to later join the Desaguadero River
Desaguadero River
The Desaguadero River is the general name of a river in western Argentina that receives a number of different names on its path of 1,515 kilometres, with its most important section named Desaguadero proper.-Spring:...
near the Salina Pampa de las Latas (or Salina Bermejo), at the common border of the provinces of San Juan, Mendoza
Mendoza Province
The Province of Mendoza is a province of Argentina, located in the western central part of the country in the Cuyo region. It borders to the north with San Juan, the south with La Pampa and Neuquén, the east with San Luis, and to the west with the republic of Chile; the international limit is...
and San Luis
San Luis Province
San Luis is a province of Argentina located near the geographical center of the country . Neighboring provinces are, from the north clockwise, La Rioja, Córdoba, La Pampa, Mendoza and San Juan.-History:...
.
The river has an average flow of 56 m³/s. Its course is 500 km long, and its drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
covers an area of 39,906 km². The Ullum Dam, at 768 m AMSL, covers an area of 32 km² and has a volume of around 440 million m³. The upper course of the river is used for water sports such as rafting
Rafting
Rafting or white water rafting is a challenging recreational outdoor activity using an inflatable raft to navigate a river or other bodies of water. This is usually done on white water or different degrees of rough water, in order to thrill and excite the raft passengers. The development of this...
and fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
, and windsurfing
Windsurfing
Windsurfing or sailboarding is a surface water sport that combines elements of surfing and sailing. It consists of a board usually two to four metres long, powered by the orthogonal effect of the wind on a sail. The rig is connected to the board by a free-rotating universal joint and comprises a...
and swimming at the Ullum Dam. Along its whole length, the San Juan River is heavily used for irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
.