As the US and Mexico continue to hammer out details of a new trade deal, a problematic old deal between the two neighbors is back in the spotlight. The “1944 Water Treaty” obligates Mexico to deliver an average of 350,000 acre-feet of water annually to the US over a five-year cycle. The most recent cycle ended on October 24, with Mexico’s water deliveries falling short more than -900,000 acre feet, according to the Texas Farm Bureau.
The 1944 Water Treaty between the United States and Mexico, formally known as the “Treaty on the Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande,” is a foundational agreement for the allocation and management of shared surface waters along the US-Mexico border. The water allocations include:
Colorado River: The United States guarantees delivery of 1.5 million acre-feet (AF) of Colorado River water annually to Mexico, plus a potential additional 200,000 AF in wetter years.
Rio Grande/Rio Bravo: Water allocation is more complex, involving six Mexican tributaries and several US streams. Mexico must deliver a minimum average of 350,000 AF per year (1,750,000 AF over five years) from six of its tributaries to the US. The US receives all flows from its tributaries, while the two countries split waters from the main channel and certain tributaries according to detailed formulas.
Tijuana River: The treaty also addresses the Tijuana River but in a more limited capacity, focusing on joint sanitation and quality management.
While the treaty has been a template for cross-border water management, it faces ongoing tensions, especially regarding Mexico’s periodic shortfalls in its deliveries to the US. The US (particularly farmers and officials in Texas) accuses Mexico of “hoarding” water in upstream dams and delivering late or insufficient volumes, making it challenging for Texas growers to plan and finance crops.
The combined water levels in the South Texas’ Rio Grande Valley region’s reservoirs remain below 27%, heightening concern among growers. Farmers of all types have been forced to scale back production or sell their farms. The citrus industry is among those feeling the pain.
“The Texas citrus industry, like every other grower in the Valley, is dying without water,” said Dale Murden, president of Texas Citrus Mutual. “We’ve already watched the state’s only sugar mill close and sugarcane production disappear. Citrus is hanging on by a thread. Without dependable water, our groves and livelihoods are at risk.”
Farmers in the region are now worried about having sufficient water to plant crops this spring. Hurricane season failed to deliver any substantial drought relief, which means the region will be facing a fourth year of water shortages.
Mexico argues that extended droughts make it impossible to meet treaty requirements while satisfying domestic needs. Recurring and worsening droughts in recent decades have strained river flows in both countries. The challenge of meeting treaty requirements has also been exacerbated by expanding urban areas and agricultural demand growth on both sides of the border.
An amendment in the treaty allows water debts to be rolled over into the next cycle during periods of “extraordinary drought.” However, US stakeholders complain it is not the first time Mexico has delayed its obligations and are skeptical that the postponed water will ever arrive.
Texas lawmakers are now asking the US federal government to take more decisive action. US Rep. Monica De La Cruz wants to include enforcement of the water treaty into the U.S.-Mexico-Canada Agreement when it comes up for review next year. U.S. Rep. Henry Cuellar, who represents the western Rio Grande Valley, thinks the US should consider withholding its water obligations from Mexico.
Other lawmakers want to renegotiate the treaty altogether and fill what some see as “loopholes.” For instance, stakeholders want to ensure there are periodic, annual releases of water rather than allowing Mexico to wait until the end of the five year period to meet its obligations.
Cuellar noted that even if Mexico were to deliver all the water currently owed, hydrology data shows that the international reservoirs that store water for the region have received significantly less water over the years from U.S. tributaries.
During the decade from 2011 to 2020, total U.S. inflow into the Amistad International Reservoir was -33% less than the decade between 1981 and 1990, an overall decrease of 4.6 million acre feet. Meanwhile, Falcon International Reservoir received -21.5% less than it did in the 1980s. Currently, Amistad is at 19% of capacity while Falcon is at 12% of capacity.
“Even if we got Mexico to put all the water back, it would not be enough,” Cuellar told The Texas Tribune, adding that leaders needed to also focus on conservation efforts and looking for other sources of water – 90% of the region’s water supply comes from the Rio Grande. “We’ve got to look at secondary sources of water, because we can’t keep going this way, it’s short-sighted,” Cuellar said. (Sources: Texas Farm Bureau, El Paso Times, The Texas Tribune, Bloomberg)
