Rio Grande

Rio Grande
Río Bravo del Norte
Historic photo of the Rio Grande, 1899
Countries United States, Mexico
States Colorado, New Mexico, Texas, Chihuahua, Coahuila, Nuevo León, Tamaulipas
Tributaries
 - left Red River, Santa Fe River, Alamito Creek, Terlingua Creek, Pecos River, Devils River
 - right Conejos River, Rio Chama, Rio Conchos, Salado River, Rio Alamo, San Juan River
Source Canby Mountain, Continental Divide
 - location San Juan Mountains, Rio Grande National Forest, Colorado, United States
 - elevation 12,000 ft (3,658 m) [1]
 - coordinates  [2]
Mouth Gulf of Mexico
 - location Cameron County, Texas; Matamoros, Tamaulipas
 - elevation 0 ft (0 m)
 - coordinates  [2]
Length 1,896 mi (3,051 km) [1]
Basin 182,200 sq mi (471,900 km²) [3]
Discharge for Rio Grande City, Texas (average and max); min of zero at many other places
 - average 3,504 cu ft/s (100 m3/s) [4]
 - max 206,950 cu ft/s (5,860 m3/s)
 - min 0 cu ft/s (0 m3/s)
Map of the Rio Grande drainage basin

The Rio Grande (known in Mexico as the Río Bravo del Norte, or simply Río Bravo) is a river that forms part of the Mexico – United States border. Its length varies as its course changes. According to the International Boundary and Water Commission its total length was 1,896 miles (3,051 km) in the late 1980s. Depending on how it is measured, the Rio Grande is the fourth or fifth longest river system in the North America.[1] It serves as a natural border between the U.S. state of Texas and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. A very short stretch of the river serves as the boundary between the U.S. states of Texas and New Mexico. The tremendous water use of big cities and vast irrigated acreage along the river has taken a heavy toll on the river's flow; less than a fifth of its historical discharge reaches the sea today.

The Rio Grande's drainage basin (watershed) is 182,200 square miles (472,000 km2).[3] Many endorheic basins are situated within, or adjacent to, the Rio Grande's basin, and these are sometimes included in the river basin's total area, increasing its size to about 336,000 square miles (870,000 km2).[5]

Contents

Geography

The Rio Grande rises in the eastern part of the Rio Grande National Forest in the U.S. state of Colorado. The river is formed by the joining of several streams at the base of Canby Mountain, just east of the Continental Divide. From there, it flows through the San Luis Valley, then south into New Mexico, passing through Espanola, Albuquerque, and Las Cruces to El Paso, Texas. Below El Paso it serves as part of the border between the United States and Mexico. The official river border measurement ranges from 889 miles (1,431 km) to 1,248 miles (2,008 km), depending on how the river is measured.[1] A major tributary, the Rio Conchos, enters at Ojinaga, Chihuahua, below El Paso, and supplies most of the water in the border segment. Other well-known tributaries include the Pecos and the smaller Devils, which join the Rio Grande on the site of Amistad Dam. Despite its name and length, the Rio Grande is not navigable by ocean-going ships, nor do smaller passenger boats or cargo barges use it as a route. It is barely navigable at all, except by small boats in a few places.

The Rio Grande rises in high mountains and flows for much of its length at high elevation; El Paso is 3,762 feet (1,147 m) above sea level. In New Mexico, the river flows through the Rio Grande Rift from one sediment-filled basin to another, cutting canyons between the basins and supporting a fragile bosque ecosystem in its floodplain. From El Paso eastward, the river flows through desert. Only in the sub-tropical lower Rio Grande Valley is there extensive irrigated agriculture. The river ends in a small sandy delta at the Gulf of Mexico. During portions of 2001 and 2002 the mouth of the Rio Grande was blocked by a sandbar. In the fall of 2003 the sandbar was cleared by high river flows of about 7,063 cubic feet per second (200 m3/s).[4]

Millions of years ago, the Rio Grande ended at the bottom of the Rio Grande Rift in Lake Cabeza de Vaca. About one million years ago (mya), the stream was "captured" and began to flow east.

History

The Upper Rio Grande near Creede, Colorado.

In the 1800s, the river was the border which the Republic of Texas used between it and Mexico, but Mexico considered the border to be the Nueces River. The disagreement provided part of the rationale for the US invasion of Mexico in 1848, after Texas had been admitted as a new state. Since 1848, the Rio Grande has marked the boundary between Mexico and the United States from the twin cities of El Paso, Texas, and Ciudad Juárez, Chihuahua, to the Gulf of Mexico. As such, crossing the river was the escape route used by some Texas slaves to seek freedom. Mexico had liberal colonization policies and had abolished slavery in 1828.[6]

In 1997 the US designated the Rio Grande as one of the American Heritage Rivers. Two portions of the Rio Grande are designated National Wild and Scenic Rivers System, one in northern New Mexico and one in Texas, at Big Bend National Park.

In the summer of 2001, a 328-foot (100 m) wide sandbar formed at the mouth of the river, marking the first time in recorded history that the Rio Grande failed to empty into the Gulf of Mexico. The sandbar was subsequently dredged, but it re-formed almost immediately. Spring rains the following year flushed the re-formed sandbar out to sea, but it returned in the summer of 2002. As of the fall of 2003, the river once again reaches the Gulf.[4]

River modifications

View of the Rio Grande from Overlook Park, White Rock, New Mexico.

The United States and Mexico share the water of the river under a series of agreements administered by the joint US-Mexico Boundary and Water Commission. The most notable of these treaties were signed in 1906 and 1944.[7][8]

Use of that water belonging to the United States is regulated by the Rio Grande Compact, an interstate pact between Colorado, New Mexico, and Texas. The water of the Rio Grande is over-appropriated: that is, there are more users for the water than there is water in the river. Because of both drought and overuse, the section from El Paso downstream through Ojinaga was recently tagged "The Forgotten River" by those wishing to bring attention to the river's deteriorated condition.[9]

There are a number of dams on the Rio Grande, including Cochiti Dam, Elephant Butte Dam, Caballo Dam, Amistad Dam, Falcon Dam, Anzalduas Dam, and Retamal Dam. In southern New Mexico and the upper portion of the Texas border segment, the river's discharge dwindles. Diversions, mainly for agricultural irrigation, have increased the natural decrease in flow such that by the time the river reaches Presidio, Texas, there is little or no water. Below Presidio the Rio Conchos restores the flow of water.[1] Near Presidio the river's discharge is frequently zero. Its average discharge is 178 cubic feet per second (5 m3/s), down from 945 cubic feet per second (27 m3/s) at Elephant Butte Dam. Supplemented by other tributaries the Rio Grande's discharge increases to its maximum annual average of 3,504 cubic feet per second (99 m3/s) near Rio Grande City, Texas. Large diversions for irrigation below Rio Grande City reduce the river's average flow to 889 cubic feet per second (25 m3/s) at Brownsville and Matamoros.[4]

Crossings

The major international border crossings along the river are at Ciudad Juárez and El Paso; Presidio, Texas, and Ojinaga, Chihuahua; Laredo, Texas, and Nuevo Laredo, Tamaulipas; McAllen-Hidalgo, Texas, and Reynosa, Tamaulipas; and Brownsville, Texas, and Matamoros, Tamaulipas. Other notable border towns are the Texas/Coahuila pairings of Del Rio–Ciudad Acuña and Eagle Pass–Piedras Negras.

The Rio Grande at Bernalillo, New Mexico, with the Sandia Mountains

The Rio Grande flowing in Big Bend National Park.

The Rio Grande in its lower course, between Matamoros (right) and Brownsville (left)

Names and pronunciation

The Rio Grande (Rio del Norte) as mapped in 1718 by Guillaume de L'Isle.

Río Grande is Spanish for "Big River" and Río Grande del Norte means "Great River of the North". In English, Rio Grande is pronounced either /ˈriːoʊ ˈɡrænd/ or /ˈriːoʊ ˈɡrɑːndeɪ/. Because "río" means "river" in Spanish, the phrase "Rio Grande River" is redundant.

In Mexico it is known as Río Bravo or Río Bravo del Norte, "bravo" meaning "fierce" or "brave". A city on its banks in Mexico bears its name (Río Bravo, Tamaulipas) and is located 10 miles (16 km) east of Reynosa, Tamaulipas, and directly across from the Texas city of Donna.

Historically, the Pueblo and Navajo peoples also had names for the Rio Grande/Rio Bravo:

The four Pueblo names likely predated the Spanish entrada by several centuries.[10]

Rio del Norte was most commonly used for the upper Rio Grande (roughly, within the present-day borders of New Mexico) from Spanish colonial times to the end of the Mexican period in the mid-19th century. This use was first documented by the Spanish in 1582. Early American settlers in south Texas began to use the modern 'English' name Rio Grande. By the late 19th century, in the United States, the name Rio Grande had become standard in being applied to the entire river, from Colorado to the sea.[10]

By 1602, Río Bravo had become the standard Spanish name for the lower river, below its confluence with the Rio Conchos.[10]

Tributaries

The largest tributary of the Rio Grande by discharge is the Rio Conchos, which contributes over twice as much water as any other. In terms of drainage basin size the Pecos River is the largest.

Tributary Average discharge Drainage basin
cu ft/s m3/s sq mi km2
San Juan River 368 10[4] 12,950 33,500[4]
Rio Alamo 130 3.68[4] 1,675 4,340[4]
Rio Salado 354 10.0[4] 23,323 60,400 [4]
Rio San Rodrigo 130 3.68[4] 1,050 2,720[4]
Devils River 362 10.3[4] 137 355[11]
Pecos River 265 7.50[4] 44,402 115,000[12]
Rio Conchos 848 24.0[4] 26,400 68,400[13]
Rio Puerco 39.5 1.1[14] 7,350 19,000[14]
Jemez River 59.5 1.68[15] 1,038 2,688[15]
Santa Fe River 10.9 0.31[16] 231 598.3[16]
Rio Chama 571 16.2[17] 3,144 8,143[17]
Conejos River 176 4.98[18] 887 2,297[18]

See also

  • Rio Bravo, Texas
  • Rio Grande border disputes
  • List of crossings of the Rio Grande
  • List of Colorado rivers
  • List of New Mexico rivers
  • List of Texas rivers
  • Rio Grande Wild and Scenic River
  • Rio Grande Valley
  • Rio Grande Gorge
  • Rio Grande Trail

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Metz, Leon C.. "Rio Grande". The Handbook of Texas Online. http://www.tshaonline.org/handbook/online/articles/RR/rnr5.html. Retrieved 17 July 2010. 
  2. ↑ 2.0 2.1 U.S. Geological Survey Geographic Names Information System: Rio Grande
  3. ↑ 3.0 3.1 "Rio Grande NASQAN Program". United States Geological Survey. http://water.usgs.gov/nasqan/docs/riogrndfact/riogrndfactsheet.html. Retrieved 17 July 2010. 
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 "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. http://www.ibwc.gov/Water_Data/water_bulletins.html. Retrieved 17 July 2010. 
  5. ↑ Benke, Arthur C.; Colbert E. Cushing (2005). Rivers of North America. Academic Press. pp. 186–192. ISBN 9780120882533. http://books.google.com/?id=-bLMR552QBMC&pg=PA186. 
  6. ↑ "The UGRR on the Rio Grande"
  7. ↑ IBWC: Treaties Between the U.S. and Mexico
  8. ↑ Thompson, Olivia N., "Binational Water Management: Perspectives of Local Texas Officials in the U.S.-Mexico Border Region" (2009). Applied Research Projects. Texas State University. Paper 313. http://ecommons.txstate.edu/arp/313
  9. ↑ "Rio Grande Sucked Dry for Irrigation, Industry", CNN SATURDAY MORNING NEWS, (Aired June 9, 2001)]
  10. ↑ 10.0 10.1 10.2 10.3 Source for historical names: Carroll L. Riley, 1995, Rio del Norte, University of Utah Press. ISBN 0874804965
  11. ↑ "Devils River Protection Campaign, Devils River Conservation Easements". The Nature Conservancy. http://www.nature.org/success/devilsriver.html. Retrieved 22 July 2010. 
  12. ↑ Largest Rivers of the United States, USGS
  13. ↑ "The Rio Conchos: An Essential Ribbon of Life". Environmental Defense Fund. http://www.edf.org/article.cfm?contentID=2902. Retrieved 20 July 2010. 
  14. ↑ 14.0 14.1 "Water resources data for the United States, Water Year 2009; gage 08353000 Rio Puerco near Barnardo, NM". USGS. http://wdr.water.usgs.gov/wy2009/pdfs/08353000.2009.pdf. Retrieved 21 July 2010. 
  15. ↑ 15.0 15.1 "Water resources data for the United States, Water Year 2009; gage 08329000, Jemez River below Jemez Canyon Dam, NM". USGS. http://wdr.water.usgs.gov/wy2009/pdfs/08329000.2009.pdf. Retrieved 20 July 2010. 
  16. ↑ 16.0 16.1 "Water resources data for the United States, Water Year 2009; gage 08317200 Santa Fe River above Cochiti Lake, NM". USGS. http://wdr.water.usgs.gov/wy2009/pdfs/08317200.2009.pdf. Retrieved 21 July 2010. 
  17. ↑ 17.0 17.1 "Water resources data for the United States, Water Year 2009; gage 08290000, Rio Chama near Chamita, NM". USGS. http://wdr.water.usgs.gov/wy2009/pdfs/08290000.2009.pdf. Retrieved 21 July 2010. 
  18. ↑ 18.0 18.1 "Water resources data for the United States, Water Year 2009; gage 08249000, Conejos River near Lasauses, CO". USGS. http://wdr.water.usgs.gov/wy2009/pdfs/08249000.2009.pdf. Retrieved 21 July 2010. 

Sources

External links

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