Water, a ticking time bomb for Mexico

Water management has become a ticking time bomb for the Mexican government, which is simultaneously battling on both the international and domestic fronts to prevent it from exploding. The Trump administration is pressuring Mexico with more tariffs to force its southern neighbor to settle its water debt of nearly one billion cubic meters, of which Mexico has committed to delivering 249 million before the end of January. Meanwhile, the high demand for water from the agricultural sector is forcing President Claudia Sheinbaum to perform a balancing act to avoid jeopardizing access to water for irrigation systems in the north of the country. With international reservoirs at critically low levels, the president must resort to sources outside the 1944 treaty, a temporary measure that helps alleviate the emergency but does not solve the problem in the long term. “From a practical standpoint, Mexico can comply, but at what cost? It is giving away everything it has,” experts summarize. The complications will begin on February 1.

The dams stipulated in the 1944 bilateral agreement, La Amistad and La Falcón, are currently at 24.1% and 11.5% capacity, respectively. They receive water from the six rivers that supply the water deliveries across the border — 2.158 billion cubic meters every five years. The Conchos River typically absorbs the majority of this water, but the prolonged drought has rendered it insufficient to meet Mexico’s obligations. Attention is now focused on the Lower Bravo region in Nuevo León and Tamaulipas, through which the San Juan River flows and where the Marte R. Gómez Dam is located. “That area is much wetter and receives more rainfall than Chihuahua currently and in recent years,” notes Alfonso Cortez, director of El Colegio de la Frontera Norte (Colef) in Mexicali, who believes that the 249 million cubic meters to which Mexico has committed are at the “limit” of what it can deliver.

This isn’t the first time this dam has been used to cover the debt, notes Mario López Pérez, an expert on the subject with decades of experience at the National Water Commission (Conagua): “It’s the emergency measure Mexico uses when it can’t complete its deliveries [...] In the last 10 years, it has been used at least three times.” Using this reservoir is highly unusual, as it contains water considered entirely Mexican and therefore not subject to any obligation to the United States.

The treaty, however, has long taken into account this possibility, with the first trace found in 1947 in Minute 186, a type of document that functions as an annex and has the same legal force as the treaty itself. “We understand that Mexico intends to divert the water discharged from the Marte R. Gómez Dam into the Rio Grande only during periods when it is not delivering water from the same source for use in the United States,” reads the engineers’ memorandum. Minutes 234 and 331, from 1969 and 2024 respectively, formalize the possibility of transferring Mexican waters northward.

This reservoir is currently at 111% capacity, according to daily monitoring by Conagua, but its use starting this week is complicated by the beginning of the irrigation season in District 026, which covers a very large area supplied by it. The small La Fragua, Las Blancas, or Luis L. de León dams could also be used, at their respective costs. “It’s an option that [the government] will have to discuss with the states involved, to see if there’s a possibility of affecting the uses for which they already have water allocated,” says Rodrigo Israel, a specialist at the College of Public Education (Colef). “It all depends on whether Mexico has the political will to deliver as much water as possible, perhaps by telling farmers: ‘This year I’m not going to deliver as much water, but I’m going to pay you for it,’ or by making an investment in infrastructure.” For example, they could invest in desalination plants or irrigation technology.

There are some precedents in this regard, in Chihuahua and especially in the Colorado River basin, where responsibilities are reversed: the United States is obligated to deliver 1.85 billion cubic meters of water to Mexico each year, sometimes with great difficulty. Since 2012, successive agreements have included — as a preventative measure — the possibility of using certain formulas to optimize water conservation through infrastructure investments, and since 2020, land-rest programs have been implemented: compensatory mechanisms to prevent farmers from harvesting in exchange for a payment that makes up for the money lost due to the work not carried out.

The United States used this mechanism in 2024 and 2025, and it is also planned for next year, explains Cortez, who believes something similar should be done in the other basin. “It’s a monumental task, but it was here too, and it’s been underway for the last five years,” the expert argues. “These mechanisms exist to address emergencies, but we can’t keep putting out fires every five years because they are very costly. You have to make structural changes to flatten the water demand curve.”

For about a quarter of a century, the lines of water supply and demand have intersected, experts say. The volume required has long exceeded what is available, and there is little control over the latter because it depends on weather conditions. The only solution is to reduce demand. “The Rio Grande basin is over-allocated. If you add drought to that, the problem is exacerbated. What you need is for there not to be the deficit we have today under normal conditions,” summarizes López.

Problems will pile up in February, the day after the first debt payment is due. If the government manages to fulfill its commitments, another 737 million cubic meters will still need to be delivered, in addition to the 431 million cubic meters that Mexico must release annually, on average, to its northern neighbor to enter the next cycle without accumulating debt. This implies an average of 53 million cubic meters per month for the next year, assuming a uniform rate of release. “If there aren’t significant changes in binational water policy, a conflict could erupt by 2030, and that’s what we need to avoid,” says Cortez. “This means that farmers in Texas and Chihuahua will have to change their production methods. I don’t see any other solution for the future, or we’ll continue to accumulate debt,” he concludes.

There are two clocks attached to the ticking time bomb that Sheinbaum must manage with extreme care. One is controlled by Trump, who has threatened to impose 5% tariffs on Mexican goods if the first 250 million cubic meters aren’t delivered next month, even though the country has until 2030, at the end of the current cycle, to comply: 2026 is a midterm election year, and this has become a central issue for Texas Republicans, where the crucial support of workers is at stake. To the south, the second ticking clock is controlled by a sector with a deep sense of grievance and in the middle of a tug-of-war with the president over low prices and the new national Water Law. Farmers have just reached an agreement with the government to avoid further blockades at Christmas, but nothing guarantees that the truce will be permanent. Pressure is mounting on both sides of the border, and time is running out.

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