Eighty years ago, the United States and Mexico worked out an agreement to share water from the two main rivers that flow through both countries: the Rio Grande and the Colorado. The treaty was created when water was not as scarce as it is now.
Water from Mexico flows to Texas’s half-billion-dollar citrus industry and dozens of cities near the border. On the Mexican side, some border states like Baja California and Chihuahua rely heavily on water from the U.S. side of the Colorado River.
Now, those water-sharing systems are facing one of the biggest tests in their history. Mexico is about 265 billion gallons behind on its deliveries to the United States.
Unpredictable weather conditions due to climate change, population growth, aging infrastructure and significant water waste have left both countries short of water and increased tensions along the border.
Maria-Elena Giner is the U.S. commissioner of the International Boundary and Water Commission, the binational agency that oversees the 1944 Water Treaty and settles disputes.
Mexico is “at its lowest levels ever” in the history of the treaty, Giner said. The treaty operates in five-year cycles, and the current deadline for deliveries is no earlier than October 2025.
But “the problem is that they are so far behind that it will be very difficult, if not statistically impossible, for them to make up that gap,” Giner said.
Victor Magaña Rueda, an environmental scientist at the National Autonomous University of Mexico, said neither country can survive without the other’s water. He called the 1944 treaty a first step.
“Now we probably have to think about how to manage water and adapt in every part to the changes we are experiencing in terms of climate,” Rueda said.
Tensions rise in the United States
Already, Texas’s last sugar mill closed this year because of a lack of water, state lawmakers said. Now, officials don’t want the same thing to happen to the state’s citrus industry, centered in the Lower Rio Grande Valley, and other agricultural operations that depend on Mexican water.
Ten lawmakers from a bipartisan congressional delegation urged the U.S. Congress to withhold money and aid to Mexico, except for border control funds, until it provides the necessary water.
“South Texas farmers and ranchers remain under financial strain and could suffer a fate similar to that of the sugar industry if Mexico continues to withhold water,” lawmakers wrote in May. “Furthermore, the lack of a reliable water supply impacts municipalities and threatens the quality of life for many American citizens living along our border.”
Rep. Henry Cuellar, a Texas Democrat, signed the letter. He said it wasn’t the first time he’d seen Mexico late with water deliveries.
But the unpredictability of this cycle has created significant difficulties for members of his congressional district, in the southwestern tip of Texas, along the Rio Grande.
“Mexico hasn’t even responded to this, which to me means one thing,” Cuellar said last month of the letter. “That means the potential loss of money is probably less important than water right now for their communities. Their silence tells you they’re more interested in water than money right now.”
Texas Republican Rep. Monica de la Cruz, another Texas representative who signed the letter, spoke to Congress in May to highlight the loss of agriculture and industry in South Texas.
“If we can’t save our farmers, then Mexico doesn’t deserve to get money that’s meant for them,” the Republican said. “We want our water, we demand our water.”
Of course, Congress has not yet funded the government for the next fiscal year, which begins in October, and could pass a temporary law to avoid a shutdown. So the threat of financial losses for Mexico remains more theoretical at this point.
As urgent as getting water from Mexico may seem, it is not the only water problem for Texas. In Texas and many other states in the US, a significant amount of water is wasted due to infrastructure failures and leaks.
The state is estimated to have lost about 129 billion gallons of water in 2022, according to the latest figures available from water loss audit data submitted by public water providers to the Texas Water Development Board.
Water Policy in Mexico
To address Texas’s water shortage, officials last year proposed a solution: a “minute,” or treaty amendment, that would allow Mexico to pay for water directly to South Texas instead of first giving two-thirds to the Mexican state of Tamaulipas, as currently specified in the treaty.
But quenching the thirst of South Texas before its citizens was likely an unattainable goal ahead of this year’s presidential election in Mexico.
Negotiations on changes to the treaty have been completed and both countries were supposed to sign it last December, but Mexico has not yet received official authorization to do so, said Giner, of the International Boundary and Water Commission.
Several Mexican officials contacted for this article declined to comment on Mexico’s water supplies to Texas and future treaty negotiations.
But across the border with Mexico, the country is facing its own water problems, in addition to water battles with the United States. A crisis in Mexico City this year has left many of its 22 million residents without clean water, as the city braces for the possibility of running out.
These difficulties, coupled with rapid population growth, have caused a serious backlog in water supplies to the United States.
In April, Mexico’s current president, Andrés Manuel López Obrador, said the country would focus on ensuring water for its residents.
“We need to prioritize domestic water, which is consumed by people rather than by companies,” he said. “We are looking for ways to address the problem of drought, water shortages: we are working on it.”
According to environmental expert Rueda, the new president-elect, Claudia Sheinbaum, is expected to take a similar approach when she takes office in October.
Problems before the last elections
This five-year cycle is not the first time Mexico has fallen behind in delivering water to the United States.
By the end of the last cycle, which ended just days before the 2020 U.S. presidential election, Mexico had delivered most, but not all, of its water to the United States.
Mexico tried to pump water from a dam in the state of Chihuahua, but was unsuccessful. Three days before the official deadline, Mexico and the United States agreed to a memorandum that allowed Mexico to transfer water to the United States in the Amistad and Falcon reservoirs along the border to avoid a shortage.
But that transfer of water from the reservoir has nearly depleted all of northern Mexico’s stored water resources, making the country even more vulnerable to future disruptions.
In the current cycle, if Mexico is unable to supply all of its water, the treaty allows it to carry the water debt forward for one cycle.
So if Mexico does not recover by the end of this cycle, it can repay its debt by the end of the next cycle. Minutes 234 stipulate that neither country can accumulate a deficit for two consecutive five-year cycles.
Rueda, an environmental scientist in Mexico, said some Mexican farmers want the treaty with the United States to be dissolved because they need water for their crops.
But doing so would be disastrous for all residents of both countries.
“If we break the treaty, then it will mean a real disaster for that region, simply because of the selfishness of a few,” he said.