The Trump administration’s unprecedented decision to deny a delivery of water to Mexico is raising alarm among experts, who fear it could jeopardize future cross-border negotiations in an increasingly thirsty region. The refusal, which marked the first such rejection in 81 years, pertained to a special request from Mexico for the transfer of additional Colorado River water to the city of Tijuana. Defending this decision, the U.S. State Department accused Mexico of failing to uphold commitments to Texas included in a 1944 water-sharing treaty. Stephen Mumme, a political scientist at Colorado State University, characterized the move as both irrational and potentially harmful. Mumme, who is also a nonresident fellow at Rice University’s Baker Institute for Public Policy, said that if he was one of the seven Colorado River basin state commissioners, he would be “really ticked off right now,” as those states are in the throes of long-term renegotiations with Mexico regarding their shared resource. “This is not designed to encourage Mexican cooperation, and Mexico can drag its feet in any number of ways,” he added. Through the 1944 treaty — which focused on the “utilization of waters of the Colorado and Tijuana rivers and of the Rio Grande” — the U.S. pledged to convey Colorado River water to Mexico, while Mexico agreed to make deliveries to the U.S. from the Rio Grande.  The treaty also created the joint International Boundary and Water Commission (IBWC), which is responsible for managing shared water deliveries and associated infrastructure. Mexico is entitled to 1.5 million acre-feet of Colorado River water each year, in line with the artery’s historic flow of from Colorado to the Gulf of California in the Mexican state of Sonora. For context, U.S. Colorado River basin states are entitled to 15 million acre-feet, and the average American household consumes about 1 acre-foot of water annually. Regarding the Rio Grande, the 1944 treaty directs Mexico to deliver 1.75 million-acre feet to the U.S. over the course of a five-year distribution cycle — with the proviso that Mexico can carry over deficits from one cycle to the next. Over the years, the country has accrued considerable Rio Grande water debt and has fallen behind on its water-sharing payments.  The U.S. State Department harped on this point last week, posting on the social platform X that Mexico’s shortfalls “are decimating American agriculture.” But Mumme maintained Mexico is “absolutely compliant with the treaty,” which allows for “extraordinary drought” and enables the countries to agree on mutually acceptable emergency measures.  As of December, about 55.4 percent of the Rio Grande basin was experiencing what the North American Drought Monitor classifies as “moderate to exceptional drought.” Data from the IBWC shows that from the October 2020 beginning of the current five-year cycle to present day, Mexico has delivered 488,634 acre-feet of water total. This amounts to just 28 percent of Mexico’s total requirement. Given the fact the current five-year cycle ends this October, Mumme recognized “that there's no chance in hell that they're going to meet it.” “This would be the second time that we've been in this situation,” he said, noting that the first time was in 1997. “The treaty provides that the U.S. can extend forbearance and allow Mexico to roll over its debt into a second cycle.”  Gabriel Eckstein, a professor at the Texas A&M University School of Law, agreed that “there’s no way they’re going to meet the obligation” and that “Texas is going to blow its gasket.” “Unless a hurricane comes in and dumps a ton of water, this is going to be the new reality for years,” Eckstein told The Hill. On Friday, record-breaking rainfall brought flash floods to the Rio Grande Valley, leading to what Texas Agriculture Commissioner Sid Miller described in a statement as “a devastating tragedy” amid widespread community destruction. “While rain was desperately needed, the sheer volume that has fallen in this region has caused severe harm,” Miller said. “The rain also fell downstream of the Rio Grande River and is unlikely to replenish water levels in Falcon Reservoir, where relief is still urgently needed.” In November, the U.S. and Mexico signed the Minute 331 agreement, which focused on improving the reliability of Rio Grande water deliveries — in part by suggesting two alternative tributaries through which the transfers could occur. Maria-Elena Giner, the U.S. commissioner for the IBWC, referred to the “overstretch water resources” in a statement at the time, adding “that the status quo was not acceptable.”  Minute 331 also promoted the development of tools that could improve conservation and efficiency, including new control infrastructure, water reuse technologies, irrigation modernization and desalination projects. Mumme said he views the signing of Minute 331 as “very positive,” while acknowledging that “it’s not going to meet the demands or expectations of South Texas irrigators.” While Texas has recognized the impacts of drought, the state also has maintained Mexico is hoarding water in upstream dams, according to a September analysis written by Mumme. Mexico, on the other hand, has agreed it must comply but also has reiterated the complications associated with persistent drought, the analysis explained. “To be clear, Mexico — which bears the greater compliance burden — is currently treaty-compliant,” Mumme wrote. “But its erratic pattern of compliance over the past decade has cost Texas farmers.”  Texas Gov. Greg Abbott (R) last week on X accused Mexico of breaching the treaty, while stressing that this “blatant disregard of water obligations must not be allowed to continue.” Miller, the agriculture commissioner, meanwhile hailed the state Senate’s passage of a resolution seeking to pressure federal officials on Mexico’s water obligations. Calling upon the Texas House to grant approval as well, Miller described farming as “the backbone of the Rio Grande Valley’s economy.” Separately, the U.S. Department of Agriculture recently approved a $280 million grant between the federal agency and the Texas Department of Agriculture, with the goal of providing economic relief to eligible Rio Grande Valley farmers.  Although Mumme recognized that the status quo has hardly been ideal, he stressed that there were plenty of proactive steps that the partners could have taken to improve current circumstances — such as agreeing on parameters for defining extraordinary drought. This is precisely what the seven U.S. Colorado River states and Mexico have done regarding water distribution and management of shortages in that basin, he explained. “That's what hasn't happened on the Rio Grande — Texas has not agreed to take any hits,” Mumme said. Eckstein, from Texas A&M, offered a similar perspective, expressing his wish that “they would do this on the Rio Grande.” “It worked really well on the Colorado, but you’ve really got a great grassroots effort on the U.S. side to do this,” Eckstein said, questioning whether any Texas players would be willing to act accordingly.   “This whole thing that they just did in trying to muscle Mexico by denying conveyance water to Tijuana — that's ridiculous,” Mumme said of the Trump administration’s denial of Colorado River water based on Rio Grande debts. “That's really a misuse of the treaty,” he continued. “It's mean spirited on the U.S.’s part, and it's an act of desperation on the Texans’ part.” Eckstein described the situation as “awkward politics,” because the Trump administration is “using one basin to try to leverage the other side on a different basin.” Responding to the U.S. delivery refusal last week, Mexican President Claudia Sheinbaum described the issue  as “important” but said it would be addressed by the IBWC and Conagua, Mexico’s national water utility. Evaluating the current stance of Mexico’s leadership, Eckstein said he believes “they’re willing to listen,” but that they might not respond well to threats. He also said he wouldn’t be shocked if Mexico sought out other markets for its agricultural products due to waning trust in the U.S. To Mumme, another sticking point is the notion that Trump’s decision won’t likely bring Texas farmers any more water — and that this “may, in fact, make it more difficult for them to negotiate the next agreement.” Mumme described the move as “typical Trump administration bullying,” criticizing the idea of conducting diplomacy via intimidation. Eckstein shared this perspective, stressing that “Mexico is not an adversary — it's a partner.” “You don't negotiate with an adversary in the same way as with a partner,” he said. “And we're treating Mexico as an adversary.” ...read more read less