Mexican President Enrique Pena Nieto has issued a series of decrees establishing water reserves, aiming to preserve sufficient supplies for tens of millions of people.
The decrees protect defined volumes of water in nearly half of Mexico’s 756 river basins, limiting them to use for humans and nature. Business and industrial access to the reserved volumes will be prohibited.
Pena Nieto and the nonprofit World Wildlife Fund group announced the reserves Tuesday.
The organization worked with Mexico’s government the past 12 years to map the country’s rivers and determine how much water is necessary to sustain life there as well as provide water for growing human populations during
There are about 42 main rivers in Mexico that run in three areas: western or the Pacific Ocean, eastern or Atlantic Ocean (the Gulf of Mexico and the Caribbean Sea) and interior, whose rivers flow into interior lagoons.
On the Pacific side, the basins of the Yaqui, Fuerte, Mezquital, Lerma-Santiago and Balsas rivers stand out; on the coast of the Gulf of Mexico, the basins of the Bravo, Pánuco, Papaloapan, Grijalva and Usumacinta rivers.
The Nazas River stands out among the endorheic basins. Some coastal plains have strong drainage deficiencies due to their low slopes, such as the areas of Baja California, Sonora, Tamaulipas, Nayarit, Tabasco and the lower parts of the Pánuco and Papaloapan basins in Veracruz. Some basins that collect waters from distant humid areas are relatively large, such as those of the Nazas, Aguanaval and Casas Grandes rivers. Others are small, such as those that together form the so-called Bolsón de Mapimí in Coahuila, Durango, and Chihuahua, or the Bolsón del Salado that encompasses the states of Zacatecas, San Luis Potosí, Nuevo León,
Due to the climatic regime of the country, in almost all rivers there is a notable difference between the volume of water carried in the dry season and the rainy season. This variation is accentuated by the water retention works and their use for irrigation, in such a way that many of the rivers that were originally permanent now become intermittent, at least in some sections of their route. In large areas, deforestation and soil erosion produce an increase in surface runoff and a decrease in rainwater infiltration.
In the Mexican territory the rivers are found in three slopes: Western or Pacific, Eastern or Atlantic (Gulf of Mexico and Caribbean Sea) and Interior, in which the rivers have no outlet to the sea.
Eastern or Gulf Slope
It is constituted by 46 important rivers, among which Usumacinta, Papaloapan, Grijalva, Coatzacoalcos, and Pánuco stand out.
Río Bravo.- It has a length of 2,001 km. It is in the Rocky Mountains and has most of its route in the United States. Half of its course is part of the border between Mexico and that country; it empties into the Gulf of Mexico. In the United States, they call it the Rio Grande.
Pánuco River.- Its length is 600 km, in the eastern basin of the Anáhuac Plateau and empties into the Gulf, in the port of Tampico.
Papaloapan River.- Its name means “river of the butterflies”; It has a length of 900 km. It is born from the junction of the Tehuacán River, which falls from the mountains of Puebla and Quiotepec, which comes down from the Sierra de Ixtlán; It passes through the Sierra Madre Oriental and receives several tributaries. It drains into the Gulf of Mexico at the height of the port of Alvarado.
Coatzacoalcos.- It is also called Rio del Istmo. It is a very large river that is nourished by the waters coming from the mountains of the Isthmus of Tehuantepec. It is born in the Sierra Atravesada and flows into the port of Coatzacoalcos.
Tonalá River.- It is the natural limit between the states of Veracruz and Tabasco, it is 325 km long.
Grijalva and Usumacinta.- The is in Tabasco and the other in Guatemala. The two irrigate the plains of Tabasco, which are the lowest in the country, together they have a length of 600 km. The most important hydroelectric plants in the country have been built in its channel. The Usumacinta is divided into three streams at the end, but retains its name; it also serves as a frontier in its middle course between Mexico and Guatemala.
Western or Pacific slope
There are around 100 rivers, including the Balsas, Lerma-Santiago, and Verde rivers.
Río Balsas.- It has a length of 771 km. In this river, there are important electricity generating plants such as the Infiernillo power station. Its basin forms a depression, of the same name, and empties into the Pacific Ocean with the name of Zacalutla River.
Río Lerma.- It is the longest river in Mexico, 965 km long. It originates at the foot of the Nevado de Toluca and in its basin, the most populated region of the country is located. Its waters are used for irrigation and electricity generation. It drains into the Chapala Lake, where the Santiago River originates and flows into the Pacific Ocean, near the port of San Blas.
Río Mayo.- It forms with the currents that move through ravines to the deep mountain ranges of the state of Chihuahua where it receives the name of Moris and descends towards Sonora, where it joins the Cedros River, whose waters feed the dam Mocúzari before going down to the valley. On one side of the river is the city of Alamos, known for its famous silver mines. The Mayo flows into the Gulf of California, near Tabaré.
Río Yaqui.- It is 554 km long, low of the Sierra Madre Occidental and meanders until it ends near the port of Guaymas. This river is used to irrigate the land that forms the Yaqui Valley, of 450 thousand hectares.
Colorado River.- It is born in the Rockies and most of its route is in the United States, it is 2,730 km long. In its low course, it serves as a border boundary between the two countries. In the national territory, it passes through the states of Sonora and Baja California to empty into the Gulf of California.
Interior Shed
It is formed by large closed basins. The most important system is that of the Nazas-Aguanaval River.
Río Nazas.- It is located in the state of Durango and its flow is used in its entirety. To improve the irrigation system, two dams were built to store their water; Lázaro Cárdenas and Francisco Zarco. This river is 560 km long and flows into the Mayrán lagoon.
Río Aguanaval.- It is the most important river in the interior or endorheic basin. It consists of three slopes that are the Chico, Lazos and Trujillo rivers. This river crosses the semi-desert zone until it penetrates into Durango and, finally, deposits its waters in the Viesca lagoon, in Coahuila. It is 500 km long.
Río del Carmen.- Originally known as Santa Clara. Before it ended in the Laguna de Patos but was dammed along with other rivers. Its length is 250 kilometers.
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