Texas Border Business
WASHINGTON – U.S. Senator John Cornyn (R-TX) sent a letter to United States Trade Representative (USTR) Ambassador Jamieson Greer urging him to bring up the ongoing 1944 Water Treaty issue during the United States-Mexico-Canada Agreement (USMCA) joint review to require Mexico to comply with its annual water deliveries to the United States. Excerpts of the letter are below, and the full letter can be found here.
The Senator wrote: “As you and the Trump Administration review the United States-Mexico-Canada Agreement (USMCA), I ask you to consider raising the 1944 Water Treaty during the 2026 USMCA review. As you know, the 1944 Water Treaty requires Mexico to deliver 350,000 acre-feet of water annually to the United States, in five-year cycles. However, during the past five-year cycle, Mexico continually failed to deliver its obligated water to the United States, hurting many South Texas agriculture producers.”
“Therefore, I respectfully request that you consider raising Mexico’s lack of compliance with the 1944 Water Treaty during the USMCA review process and consider any possible mechanisms to ensure Mexico complies with the obligated annual water deliveries to the United States,” he continued.
“I appreciate your leadership on the USMCA and trade relations with Mexico, and I look forward to working with you and President Trump as you examine the 1944 Water Treaty and its possible inclusion in the USMCA review,” he concluded.
Background:
Sen. Cornyn has led the charge in Congress to boost South Texas’ water supply and ensure Mexico fulfills its treaty obligations to provide annual deliveries of water to South Texas farmers and ranchers. In addition to securing more than $280 million in emergency assistance for Rio Grande Valley farmers and producers affected by the water shortage, he led a request last year to U.S. Secretary of State Marco Rubio asking for renewed efforts to force Mexico to comply with the 1944 Water Treaty while also securing Secretary Rubio’s commitment to hold Mexico accountable for delays.
In December, President Trump announced he would impose a tariff on Mexican imports due to Mexico’s failure to comply with the 1944 Water Treaty. On December 12, 2025, the United States and Mexico agreed to address water obligations under the 1944 Water Treaty, and Mexico began to repay its water deficit in Texas that month.
Previously, Sen. Cornyn sent a letter to NADBank urging for the restoration of their Water Infrastructure Fund, raised alarms after a Rio Grande sugarcane mill closed due to acute water shortages, cosponsored a resolution supporting diplomacy, and sent a letter to then-U.S. Secretary of State Blinken urging the Department to engage on Mexico’s violation of the intent of the treaty. Senator Cornyn also led a letter to the Chairmen and Ranking Members of the House and Senate Appropriations Subcommittees on State and Foreign Operations urging them to withhold designated funds from Mexico until they enter into an agreement with the U.S. to balance the deficit of the water deliveries, which the House Appropriations Committee included in their funding bill. The Senator also introduced legislation last year to hold the Mexican government accountable for not meeting its water delivery requirements.
Under the Treaty Relating to the Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande, Mexico is obligated to deliver an average of 350,000 acre-feet of water annually over a five-year cycle as its contribution to the Rio Grande’s water supply. However, Mexico has consistently delayed fulfilling its water obligation until the end of the five-year cycle, which hinders South Texas farmers’ ability to plan for and grow crops as well as ranchers’ ability to provide water to livestock.
Senator John Cornyn, a Republican from Texas, is a member of the Senate Finance, Judiciary, Intelligence, Foreign Relations, and Budget Committees.
information Source: Office of Senator Cornyn
