Chihuahua.- The historical record of the National Water Commission (Conagua) places Chihuahua with a serious annual water deficit, since an average volume of 7,275 million cubic meters of water leaves the state and only 390 million enter, which translates into barely five percent of the total.
Flows from Texas and Durango enter the state, but they leave to a greater extent to Sonora and Sinaloa without any control due to the natural shape of the currents, as well as to the Rio Grande to comply with the provisions of the International Boundary and Water Treaty.
Despite this disparity, the entity does not receive programs in return such as payment for environmental services or extraordinary investments.
In the “Analysis of different types of agriculture for the conceptualization of a new rurality. The Chihuahua case” – carried out by Víctor Quintana and Martín Solís as consultants at the subregional headquarters of the Economic Commission for Latin America and the Caribbean (ECLAC) in Mexico – is recorded as the main problem of rural production in the state.
“As befits a state as extensive but arid as Chihuahua, water currents, that is, rivers and streams, are abundant, but the vast majority are seasonal. Only a few carry water all year round, although in the dry season their flow is reduced to a minimum,” the researchers state.
The Conchos River appears as the most important in the state and also the main Mexican tributary of the Rio Grande. Its basin covers more than half of the state’s 67 municipalities. In its course are the two largest dams of the entity: La Boquilla and El Granero.
The hydrography of Chihuahua, given the large extension of the state, is distributed in several basins and hydrological regions, which are Southern Sonora and Sinaloa towards the Pacific Ocean; Bravo-conchos, towards the Gulf of Mexico; to the north and northwest, Cuencas Cerradas del Norte and, to the southeast, Mapimí.
“This is largely the problem of Chihuahua. There are many water currents in its territory, even if they are intermittent, which capture very important flows due to rain, snowfall or thaw. However, most of the water is poured into other rivers that flow to other states and irrigate fertile valleys in them,” they explain.
“In the mountains of Chihuahua, rivers arise whose waters are only partially used in the state, but which become an important source of wealth for other entities, whether on the Bravo slope or the Yaqui, Mayo and Strong”.
An unfavorable balance
The balance is unfavorable in the runoff that enters the state and those that leave each year, due to rain, snowfall and thaw, mainly from the areas most favored by precipitation.
In the north of the state, water enters Chihuahua through Texas from the Río Bravo or Río Grande, as it is called in the United States. The 2020 record establishes that a volume of 120 million cubic meters entered the entity through that region through the upper Río Bravo.
From Durango, through the Florido River, water also flows to the valleys of southern Chihuahua, for 270 million cubic meters.
In contrast, an estimated volume of five thousand 648 million cubic meters flows from Chihuahua to Sonora and 930 million cubic meters to Sinaloa, a product of natural runoff from the forested area of the entity.
In addition, Chihuahua contributes 697 million cubic meters of water to the lower Río Bravo through the Conchos River at the northeast exit of the entity, as part of the International Boundary and Water Treaty of 1944 with the United States, to pay part of the that the neighboring country sends to the valleys of Baja California and Sonora through the Colorado River.
“In exchange for this delivery (Chihuahua) does not receive compensation of any kind, no payment for environmental services, which makes the availability of water for the state very precarious and makes it largely dependent on groundwater,” state Quintana and Solís in the extensive analysis of water in the state and its potential for agricultural production, which maintains first national places in different areas, but is on the limit of sustainability.
Without rain and with dry dams
Chihuahua researchers point out that the state’s location at the latitude of the planet’s great deserts makes it especially vulnerable to the manifestations of climate change, especially droughts.
“This factor is key to understanding both the evolution of the Chihuahuan agricultural sector and the dispute over access to natural resources and capital goods that cushion said vulnerability, and, at the same time, it deepens the gaps between those who have more resources with the “have to contain or resist the effects of climate change and those who do not have them,” they consider.
Rainfall is seen as the first determining factor. In the 35 years from 1985 to 2020, in 25 of them the annual precipitation has been less than 500 millimeters and in 11 of these, even less than 400 millimeters.
“Now, the already meager volume of precipitation does not fall in its entirety during the production cycle, which makes rainwater less usable for crops. It only rains consistently for a maximum of 17 days from June to September,” they detail.
“In addition, the lack of humidity in the environment makes evaporation easier and not enough rainwater flows to fill dams and recharge aquifers (…) This rainfall regime has meant that in the last forty years “Without significant changes, the extent of the planted area in Chihuahua and the harvested area will follow the variations in precipitation.”
The current situation of the dams reported by Conagua at the end of this year’s agricultural cycle, on September 30, clearly reflects how the water problem in the state continues to worsen.
The average of the 10 dams in the state – eight of which are small compared to the large capacity of La Boquilla, the largest in Chihuahua – closed last month with just 19.3 percent of storage.
In June of this year, the average of the dams was at 25.1 percent storage, basically due to a high level of El Granero, the reservoir located in the low waters of the Conchos, at the northeast exit of the entity, due to where the water is provided for the treaty with the United States.
Previously, it had been close to 50 percent in August 2023 and August 2022, after the rains that partially alleviated the summers of those years.
But La Boquilla, located in the upper current of the Conchos, closed September with 15.8 percent storage this year, which does not guarantee the next agricultural cycle; In June of this year it had 21.9 percent; In August 2023 and 2022 it was around 50 percent.
Las Vírgenes, in the current of the San Pedro River, ended with just 11.6 percent of storage and began this year’s agricultural cycle with just 17.6 percent, a level that had ups and downs thanks to few and occasional rains in recent weeks; In August of last year it was close to 50 percent and in 2022 it reached up to 107.1 percent, thanks to the rains that favored the regions of the tributaries that flow into its basin.
This year, the low level of storage in the central-southern area of the entity, the most productive in the state primary sector, did not allow the planting of all available hectares given the lack of guarantee of greater volumes of water; This situation will worsen for agricultural and livestock production in the next cycle.
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