Rio Conchos

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Río Conchos
Conchos basin map.png
Map of the Conchos
Map of the Rio Grande watershed, showing the Rio Conchos joining the Rio Grande near Ojinaga.
Country Mexico
State Chihuahua (state)
Physical characteristics
Source Sierra Madre Occidental
 - location Guadalupe, Chihuahua
Mouth Rio Grande
Ojinaga, Chihuahua
 - coordinates
29°35′N104°25′W / 29.583°N 104.417°W / 29.583; -104.417 Coordinates: 29°35′N104°25′W / 29.583°N 104.417°W / 29.583; -104.417 [1]
Length560 km (350 mi)
Basin size68,400 km2 (26,400 sq mi) [2]
 - location IBWC station 08-3730.00, near Ojinaga [3]
 - average24 m3/s (850 cu ft/s) [3]
 - minimum0.09 m3/s (3.2 cu ft/s)
 - maximum1,490 m3/s (53,000 cu ft/s)

The Río Conchos (Conchos River) is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte (known in the United States as the Rio Grande) at the town of Ojinaga, Chihuahua.

Chihuahua (state) State of Mexico

Chihuahua, officially the Free and Sovereign State of Chihuahua, is one of the 31 states of Mexico. It is located in Northwestern Mexico and is bordered by the states of Sonora to the west, Sinaloa to the southwest, Durango to the south, and Coahuila to the east. To the north and northeast, it has a long border with the U.S. adjacent to the U.S. states of New Mexico and Texas. Its capital city is Chihuahua City.

Rio Grande river forming part of the US-Mexico border

The Rio Grande is one of the principal rivers in the southwest United States and northern Mexico. The Rio Grande begins in south-central Colorado in the United States and flows to the Gulf of Mexico. Along the way, it forms part of the Mexico–United States border. According to the International Boundary and Water Commission, its total length was 1,896 miles (3,051 km) in the late 1980s, though course shifts occasionally result in length changes. Depending on how it is measured, the Rio Grande is either the fourth- or fifth-longest river system in North America.

United States federal republic in North America

The United States of America (USA), commonly known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.



The Rio Conchos is the main river in the state of Chihuahua and the Rio Grande's largest tributary. [4] It is one of the most important river systems in all of northern Mexico. [2] The Conchos has several reservoirs that make use of its water for agricultural and hydropower uses.


The Conchos rises in the Sierra Madre Occidental in the municipality of Bocoyna, Chihuahua, where it heads east and receives several tributaries along the way. At Valle de Zaragoza municipality, Chihuahua, it is stopped at the La Boquilla Dam, the largest in Chihuahua forming Toronto Lake. It then heads east again, forming Colina Lake and then passes through Camargo, Chihuahua, the main agricultural center in the region, where it receives the Florido as a tributary.

Sierra Madre Occidental mountain range

The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that form the western 'backbone' of North America, Central America, South America and West Antarctica.

Valle de Zaragoza Municipal Seat in Chihuahua, Mexico

Valle de Zaragoza is a settlement in the Mexican state of Chihuahua. It serves as the municipal seat of the surrounding municipality of Valle de Zaragoza. Ranchera singer Francisco Avitia was born in Valle de Zaragoza.

La Boquilla Dam

La Boquilla Dam is a masonry arch-gravity dam on the Rio Conchos in Chihuahua, Mexico. It was built in 1910 to provide hydroelectricity, irrigation and flood control, and forms Toronto Lake with a capacity of 2.903 cubic kilometres (2,354,000 acre⋅ft). The dam and the nearby town of Boquilla de Conchos are named for the abrupt narrowing of the Conchos valley where the dam was built: boquilla means "nozzle" or "mouth".

From there, the Conchos heads north, receiving the San Pedro near Delicias, Chihuahua, entering the Chihuahua Desert and cutting a path through it, before turning to the northeast. At Aldama, Chihuahua, it is dammed by the Presa El Granero, then cuts through the Peguis Canyon, before forming a last dam (Toribio Ortega) near Ojinaga. At Ojinaga, it joins the Rio Bravo (Rio Grande in the U.S.).

Delicias, Chihuahua Place in Chihuahua, Mexico

Delicias is a city in the Mexican state of Chihuahua and serves as the seat of the municipality of the same name. It is located southeast of the state capital, Chihuahua. Delicias was declared an official municipality of the state of Chihuahua on January 7, 1935. Delicias is a small industrial city and a major agricultural center located in the Conchos River Valley. As of 2015, the city of Delicias had a population of 148,045 inhabitants, while the metropolitan area had a population of 223,993 inhabitants. It was founded on 30 April 1933, making it one of Mexico's youngest cities. The municipality of Delicias is one of the smallest in the state in terms of size area.

El Granero Dam

El Granero Dam is an embankment dam on the Rio Conchos in north-central Chihuahua, Mexico. The dam was completed in 1968 to provide irrigation and flood control for the lower Rio Conchos valley.


The World Wide Fund for Nature (WWF) has included the Rio Conchos in its Global 200 Freshwater Ecoregions assessment. The Global 200 is a list of freshwater ecoregions (rivers systems and lakes, for example) that the WWF considers of global importance for biodiversity conservation. The WWF's assessment of the Rio Conchos rates its biological distinctiveness as "globally outstanding" and its conservation status as critically endangered, putting it in the "priority I" category of needing conservation attention. [5]

World Wide Fund for Nature international non-governmental organization

The World Wide Fund for Nature (WWF) is an international non-governmental organization founded in 1961, working in the field of the wilderness preservation, and the reduction of human impact on the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States.

The Global 200 is the list of ecoregions identified by WWF, the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". So, for example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.

Biodiversity Variety and variabiity of life forms

Biodiversity refers to the variety and variability of life on Earth. Biodiversity typically measures variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. Marine biodiversity is usually highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future.

The Rio Conchos contains the only free-flowing large river environment left in the Rio Grande drainage basin. Its river and spring habitat ecosystems are relatively intact and support a highly endemic fish fauna. [6] Twelve of its forty-seven native fish are endemic, as are twelve of its 46 native herpetofauna species. The strong biodiversity has survived in part because the river's ecology has not been affected by channel modifications. The Rio Conchos region is significant not only for its surface water biota, but also its specialized spring and cave habitats, which contribute to the region's high endemism. However, conditions are being damaged by industrial pollution, sewage, agricultural wastes, flow regulation, exotic species, and overgrazing. Other threats include poor land and water management practices, such as clear-cutting along the upper Rio Conchos. [5]

Endemism ecological state of being unique to a defined geographic location or habitat

Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species that are restricted to a defined geographical area.

Herpetology study of amphibians and reptiles

Herpetology is the branch of zoology concerned with the study of amphibians and reptiles. Birds, which are cladistically included within Reptilia, are traditionally excluded here; the scientific study of birds is the subject of ornithology.

River engineering

River engineering is the process of planned human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the water resources, to protect against flooding, or to make passage along or across rivers easier. From Roman times, rivers have been used as a source of hydropower. From the late 20th century, river engineering has had environmental concerns broader than immediate human benefit and some river engineering projects have been concerned exclusively with the restoration or protection of natural characteristics and habitats.

See also

Related Research Articles

Ecoregion Ecologically and geographically defined area that is smaller than a bioregion

An ecoregion is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than an ecozone. All three of these are either less or greater than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation.

Presidio, Texas City in Texas, United States

Presidio is a city in Presidio County, Texas, United States. It stands on the Rio Grande, on the opposite side of the U.S.–Mexico border from Ojinaga, Chihuahua. The name originates from the Spanish and means "jail". The population was 4,167 at the 2000 census, and had increased to 4,426 as of the 2010 US census.

Lake Chapala lake

Lake Chapala is Mexico's largest freshwater lake. It lies in the municipalities of Chapala, Jocotepec, Poncitlán, and Jamay, in Jalisco, and in Venustiano Carranza and Cojumatlán de Régules, in Michoacán.

The Rio Grande has changed course several times in recorded history, leading to a number of border disputes and uncertainties, both international and between individual U.S. states:

The Boundary Treaty of 1970 is a treaty between the United States and Mexico that settled all outstanding boundary disputes and uncertainties related to the Rio Grande border between them.

Amistad Reservoir reservoir on the Rio Grande at its confluence with the Devils River in Texas and Mexico

Amistad Reservoir is a reservoir on the Rio Grande at its confluence with the Devils River 12 miles (19 km) northwest of Del Rio, Texas. The lake is bounded by Val Verde County on the United States side of the international border and by the state of Coahuila on the Mexican side of the border; the American shoreline forms the Amistad National Recreation Area. The reservoir was formed in 1969 by the construction of Amistad Dam. The dam and lake are managed jointly by the governments of the United States and Mexico through the International Boundary and Water Commission. The name of the dam and lake is the Spanish word for "friendship". The reservoir is also known as Lake Amistad.

Orinoco Delta

The Orinoco Delta is a vast river delta of the Orinoco River, located in eastern Venezuela.

Lerma River river in Mexico

The Lerma River is Mexico's second longest river. It is a 750 km-long (470 mi) river in west-central Mexico that begins in Mexican Plateau at an altitude over 3,000 metres (9,843 ft) above sea level, and ends where it empties into Lake Chapala, Mexico's largest lake, near Guadalajara, Jalisco. Lake Chapala is the starting point of Río Grande de Santiago, which some treat as a continuation of the Lerma River. In combination, the two are often called the Lerma Santiago River. The Lerma River is notorious for its pollution, but the water quality has demonstrated considerable improvement in recent years due mostly to government environmental programs and through massive upgrading projects of sanitation works.

Grande de Santiago River river in Mexico

The Grande de Santiago River is one of the longest rivers in Mexico, measuring up 433 km (269 mi) long. The river begins at Lake Chapala and continues roughly north-west through the Sierra Madre Occidental, receiving the Verde, Juchipila, Bolaños, and other tributaries. At La Yesca, the La Yesca Dam was completed in 2012 and the El Cajón Dam was completed downstream in 2007. Below El Cajón, the Aguamilpa Dam was completed in 1993, creating a reservoir covering a large part of the territory of the municipality of El Nayar in Nayarit. From Aguamilpa, the river descends to the coastal lowlands, passing by Santiago Ixcuintla and empties into the Pacific Ocean, 16 km (10 mi) northwest of San Blas, in Nayarit. The river is viewed by some sources as a continuation of the Lerma River, which flows into Lake Chapala.

Mexican Plateau Region in Chihuahua, Mexico

The Central Mexican Plateau, also known as the Mexican Altiplano, is a large arid-to-semiarid plateau that occupies much of northern and central Mexico. Averaging 1,825 m (5,988 ft) above sea level, it extends from the United States border in the north to the Trans-Mexican Volcanic Belt in the south, and is bounded by the Sierra Madre Occidental and Sierra Madre Oriental to the west and east, respectively.

Ojinaga Town in Chihuahua, Mexico

Ojinaga is a town and seat of the municipality of Ojinaga, in the northern Mexican state of Chihuahua. As of 2015, the town had a total population of 28,040. It is a rural bordertown on the U.S.-Mexico border, with the city of Presidio, Texas, directly opposite, on the U.S. side of the border. Ojinaga is situated where the Río Conchos drains into the Río Grande, an area called La Junta de los Rios. Presidio and Ojinaga are connected by the Presidio-Ojinaga International Bridge.

Santa Cruz de Rosales Villa in Chihuahua, Mexico

Santa Cruz de Rosales is a town and seat of the municipality of Rosales, in the northern Mexican state of Chihuahua. As of 2010, the town had a population of 5,570, up from 5,377 as of 2005

Mauricio De la Maza-Benignos Mexican ichthyologist

Mauricio de la Maza-Benignos is a Mexican Conservationist, Naturalist and Zoologist. He is also a member of Mexico's National System of Researchers. In addition to his work in ichthyology, he is an agronomist and zootechnician, a jurist, an administrator, and an editor. He earned his bachelor's degree at the Monterrey Institute of Technology and Higher Education, a Master of Business Administration at The University of Lancaster, a Ph.D. summa cum laude, at the Autonomous University of Nuevo León, and studied Law, under a merit scholarship at the TecMilenio University. In 1994 he obtained the “Best students of Mexico Award” by the “National Permanent Committee for the Best Students of Mexico”, and in 2014 he was awarded first place in the “Dr. José Álvarez Del Villar” prize for his doctoral thesis, by the Mexican Ichthyology Society. He developed his doctoral thesis under the direction of Professor and Ichthyologist Ma. de Lourdes Lozano-Vilano, with whom he continues to do research. He also collaborates with geneticist and ichthyologist Dr. Evan W. Carson at UNM, mainly in the area of conservation genetics. In 2015 he was awarded the UANL Research Prize to the best scholar paper in the Natural Sciences during 2014. From 2006―2011, he served as Director for the World Wide Fund for Nature (WWF), Chihuahuan Desert Program; and from 2011― as Conservation Science Director and Chief Executive Officer for Mexican NGO, Pronatura Noreste.


  1. Rio Conchos at GEOnet Names Server
  2. 1 2 "The Rio Conchos: An Essential Ribbon of Life". Environmental Defense Fund. Archived from the original on 24 July 2010. Retrieved 20 July 2010.
  3. 1 2 "Water Bulletin Number 75: Flow of the Rio Grande and Related Data; From Elephant Butte Dam, New Mexico to the Gulf of Mexico". International Boundary and Water Commission. 2005. Retrieved 17 July 2010.
  4. Benke, Arthur C.; Colbert E. Cushing (2005). Rivers of North America. Academic Press. pp. 186–192. ISBN   978-0-12-088253-3.
  5. 1 2 Abell, Robin A.; David M. Olsen; Eric Dinerstein; Patrick T. Hurley; et al. (2000). Freshwater Ecoregions of North America: A Conservation Assessment. Island Press. pp. 93, 103, 188–189. ISBN   978-1-55963-734-3.
  6. De la Maza-Benignos, M. (ed). 2009. Los Peces del Río Conchos. Alianza World Wildlife Fund-Fundación Gonzalo Río Arronte