RIO BALSAS: HISTORY, CHARACTERISTICS, ROUTE, TRIBUTARIES, FLORA, FAUNA - GEOGRAPHY - 2024

The Balsas River is located in the central region of Mexico. With 771 km in length, it is one of the longest rivers in the country, since it irrigates 8 of the 32 Mexican states with its waters.

The Balsas bathes an area of ​​approximately 117,305 km ², which represents 6% of the national territory. In 2010, a total of 10,990,154 people lived throughout the basin, representing 10% of the national population.

The average annual rainfall of the Balsas is 978 mm. Photo: Javier Alejandro Lara Bautista

The Balsas riverbed has been a fundamental engine for the development of the country, since it supplies 10% of the electrical energy requirements of Mexico; and 25% of the state needs. By 2009, 78% of the surface water in the basin was destined to the production of this important resource.

History

Prehispanic era

The oldest settlements in the Balsas river basin date back 22,000 years and are concentrated in its lower part, on the Pacific coast.

Throughout the basin, different aboriginal cultures were established, among which Mexica, Tarascan, Mixtec, Chubias, Teotihuacanas, Chichimecas, Yopes, Mezcala, Purépechas, Amuzgos, Mayans, Toltecs, Coixcas, Pantecas, Matlazincas, Tolimecas, Tlahuicas, Olmecs, Cuitlaltecas and Tlaxcalans. These cultures shaped their ways of life around the river and the natural resources present in the area.

There is bibliographic evidence that reflects the nature of the relationships that were established between these peoples, which were found at different levels in their cultural evolution. In the micro universe of pre-Hispanic Mexico alliances, conquests, subjugation and betrayals abound between the cultures that shared the region.

The basin has a great historical and cultural richness contained in the different archaeological sites. Among the most prominent are Tzintzuntzan, Tingambato, Cacaxtla, Cuetlajuchitlán, Palma Sola, Teopantecuanitlán, Tehuacalco, Xihuacan, La Soledad de Maciel, Xochipala, Cueva de Oxtotitlán and Ixcateopan de Cuauhtémoc.

Hispanic era onwards

In 1519, during the conquest of Mexican territory, the explorer Hernán Cortés went to the instance of the Tlaxcala Senate to request permission to pass his troops through his territory on the way to Tenochtitlán.

Cortés expected that his enmity with the Mexica would win their support or at least their neutrality, however, the Senate did not agree to his request by not trusting the intentions of white men from the East.

On September 2, 1519, the Tlaxcala republic faced the Spanish forces commanded by Cortés, being defeated. After the conquest of Tenochtitlán, expeditions began in 1520 to locate the mining resources available in the territory of the current state of Guerrero.

Towards 1810, after 300 years of Spanish rule, cities had been established throughout the territory of the basin. In the main populated centers, the Creoles were infused by the philosophical currents of the time with a desire for independence. This was finally achieved on September 27, 1821 with the entry of the Trigarante Army to Mexico City.

In 1937 the Mexican state government began the construction of the first hydroelectric plants in the upper basin of the Balsas River. Due to the topography of the region, the Balsas basin has great potential for hydroelectric production. For this reason, in 1940 the Federal Electricity Commission prohibited the use of its waters and its tributaries for any use other than the generation of electricity.

On March 22, 2011, the then president of Mexico, Felipe Calderón Hinojosa, lifted the ban allowing the use of the Balsas river basin for human consumption.

General characteristics

The Balsas river basin bathes 420 municipalities in the Mexican states of Guerrero, Jalisco, Michoacán, Mexico, Morelos, Oaxaca, Puebla and Tlaxcala. The river runs from west to east the depression that forms between the Neovolcanic mountain range and the Sierra Madre del Sur.

The climate in the region varies depending on the height, presenting temperate, hot and dry climates. The rainy season occurs from June to September with an uneven distribution of rainfall over the territory of the basin, with lower rates towards the east.

The average annual rainfall is 978 mm and presents minimum levels of 525 mm in the states of Tlaxcala and Puebla, registering a total annual maximum of 2,317 mm in the state of Morelos.

High daytime temperatures cause 81% of the water from rainfall to return to the atmosphere, adding a huge percentage of humidity to the region's climate. 15% of the water from rainfall feeds the flow of the Balsas River. Meanwhile, the remaining 4% seeps into the ground and into the aquifers of the basin.

Birth, route and mouth

The Balsas River is born at the confluence of the San Martín and Zahuapan rivers, in the Puebla valley between the Mexican states of Puebla and Tlaxcala in the center of the country.

The head of the Balsas is located in the Puebla valley, between the Sierra Nevada and the Sierra de Tlaxco at an altitude of approximately 1,000 meters above sea level.

Immediately after its birth it takes a southern direction. 20 km from the city of Puebla, it forms the canyon known as Balcón del Diablo and heads south west. After its encounter with the Huajuapan river, turn west.

On its way to the ocean, it crosses the Sierra Madre, heading south to form its delta near the town of Zacatula, in the state of Guerrero. The riverbed of the Balsas river is divided into three sections: high, medium and low.

The upper Balsas occupies the territory of Morelos and parts of Tlaxcala, Puebla, Oaxaca, Mexico and Guerrero. The middle Balsas occupies portions of Mexico, Michoacán and Guerrero. The lower Balsas encompasses portions of Jalisco and Guerrero. After a journey of approximately 771 km, the Balsas River empties through its delta into the Pacific Ocean.

Contamination

The nature of the Balsas River is affected by municipal, industrial and agricultural wastewater that flows into its channel.

Only 43 municipal treatment plants are installed in the basin for the 420 municipalities. This structural deficit means that most of the populations discharge their wastewater into the tributaries of the Balsas or directly into its waters.

In any case, the point of entry of organic and inorganic liquid waste of urban origin does not make a difference, since they all go to the main channel of the Balsas and compromise the quality of its waters.

Despite its small volume, industrial wastewater has a great impact on the ecological balance of the Balsas, since the main industrial centers are located in ecologically critical regions of the upper basin and delta.

Throughout the basin there are a total of 231 industrial wastewater treatment plants installed, however, the presence of polycyclic aromatic hydrocarbons and organochlorine compounds has been recorded in its waters. These compounds are very harmful to aquatic life and affect the most productive ecosystems in the region.

Added to this is the impact of agrochemicals from the return of agricultural waters and solid waste, which are dumped by the inhabitants in an irresponsible way. All these elements make the Balsas River an ecosystem with severe pollution problems.

Economy

The main economic activity of the Balsas river basin is the production of hydroelectric energy. 78% of the available surface water is dedicated to this activity, in order to cover parts of the needs of the most populated states in the region and contribute a quota for the national supply. Altogether, the hydroelectric plants installed in the Balsas riverbed have a potential of 2,330 MW.

Second is agricultural production. This industry consumes 7,909.72 mm ³ of water to irrigate 174,089 hectares of crops. The area is supplied by dams that work through canals. Among the main products of the region are sugar cane, lemon, sorghum, mango, sesame and vegetables.

Main cities that travels

The territory of the Balsas river basin is occupied by 10,990,154 people, 10% of the national population. Internally, 68% of the population lives in the upper basin.

In 1995 there were 17 populated centers with more than 50,000 people in the Balsas river basin, which accounted for 32% of the population. 35% lived in medium-sized cities with between 2,500 and 50,000 inhabitants and 33% were located in communities with less than 2,500 inhabitants.

Among the most important cities in terms of population that the Balsas crosses on its way to the sea are Puebla, in the state of Puebla, with 1,160,000 inhabitants; Lázaro de Cárdenas in the state of Michoacán with 178,817 inhabitants and Tlaxcala in the state of Tlaxcala, with 36,500 inhabitants.

Tributaries

The Balsas River collects water from rainfall and rivers located in the highlands that surround its basin, on its way to lower lands. Among the most important tributaries are the San Martín, Tacámbaro, Amacuzac, Zahuapan, Tepalcatepec, Cutzamala, Mixteco, Huajuapan, Acatlán, Iguala and Temalcatepec rivers.

Flora

The vast area of ​​the Balsas river basin shelters different types of vegetation that vary depending on the height and temperature. Among the most representative types of vegetation are tropical, thorny and oak-pine forests, xerophilous scrub, aquatic and underwater vegetation.

The tropical forest vegetation is the most widespread in the basin, located between 0 and 1,600 meters above sea level. They are dense plant populations made up of trees and bushes.

Among the most common species are copal, Spanish jaboncillo, pochota, guayacán, amate negro, higuerón, yellow saiba, noma, maguey, palo bobo, guásimo, cucharito, hawthorn, romerillo, red tree sage, white wood, castilla oak, chupandía, pink lapacho, Brazilian wood, cuachalalate, pochote boludo, papache, guanacaste, river almond, Indian bean and Mayan walnut.

The thorny forest vegetation is concentrated in the lower basin of the Balsas River. The most common species are palo verde, soft mesquite, teaspoon from the hill, palo prieto, black bow, cholulo, azulillo, and break coat.

The oak-pine forest reaches heights of up to 35 meters. In the Balsas river basin, it is located in the upper parts of the Neovolcanic mountain range and the Sierra Madre del Sur. The most common species are aguatle, avocado oak, moctezuma pine, capulincillo oak, chimonque pine, white oak, pacingo, tesmolillo oak, white ocote and ax bank oak.

The vegetation of the xerophilous scrub reaches a maximum of 4 meters in height and is abundant in the states of Puebla, Michoacán and Oaxaca. The most representative species are bitter short, turkey tail, rattlesnake, jiotilla, wild olive, spider, bearded pitahaya and broom.

In the Balsas basin, the aquatic and underwater vegetation has a distribution limited to the spaces where human activities allow them to flourish. The sites with the highest concentration are lagoons, swamps and dams.

Some of the species found in this area are cattails, rush, horsetail, lama, duckweed, Mexican mosquito fern, water hyacinth, spiky moss, water cabbage, water lilac, burdock, clavito, clover fern of water, sensitive of water and nymph of thorny water.

Fauna

In the territory of the river basin of the Balsas river there are several areas that are under different protection schemes, in order to protect the plant and animal species that inhabit them. These protection zones also fulfill the function of guaranteeing the ecological balance of the river, serving as zones to allow its purification and the self-regulation of its waters.

In the region there are species that have been cataloged under threat and in danger of extinction. The largest number of endemisms in the region corresponds to vertebrates, with 233 endemic species.

Among the fish, the presence of species that inhabit salt water stands out, these are found in the lower area of ​​the river delta, whose salinity allows their presence.

You can see crab, stork, green iguana, teal, minor boludo duck, snook, garrobo, lebrancha, olive ridley turtle, sardinita, blue-tailed cuije, mojarra, American hawk, yellow snapper, owl, red-tailed cuije, jungle hawk, sole, proboscis crocodile, mate, common boa, prawn, water warbler and tilapia.

References

1. Rafael Fernández Nava, Floristic list of the Balsas river basin, Mexico, Polibotánica Magazine Núm. 9 (1998). Taken from polibotanica.mx
2. The Balsas river basin, National Institute of Ecology and Climate Change, taken from inecc.gob.mx.
3. Juan Carlos Valencia-Vargas, Development of the hydrological region of the Balsas by modifying its closure, Technology and Water Sciences Magazine digital version, vol.6 (2015). Taken from scielo.org.mx.
4. Lower Basin of the Balsas River, website of the National Commission for the Knowledge and Use of Biodiversity (CONABIO), Taken from conabio.gob.mx.
5. The water from the Balsas river will be for human consumption, Excélsior newspaper, digital version, published on March 19, 2011. Taken from excelsior.com.mx.