According to a treaty made back in 1944, Mexico agreed to send the US 1.75M acre-feet of water via the Rio Grande every 5 years. In return, the US supplies 1.5M acre-feet of water to Mexico along other parts of the US southern border.
However, Mexico is behind on its deliveries due to persistent drought in its own major reservoirs. Scant deliveries have intensified water shortages in Texas after years of drought. Back in February, the Rio Grande Valley Sugar Growers sugar mill was forced to shut down due to a lack of water from Mexico, affecting over 500 employees.
“The 1944 water treaty between the United States and Mexico obligates both countries to share water resources from the Colorado and Rio Grande rivers,” the letter said. “Despite ongoing diplomatic efforts, Mexico still fails to provide minimum, consistent water deliveries to the United States from the Rio Grande, instead waiting until the end of a five-year cycle to deliver the water owed to America.”
Currently, the treaty has no penalties in place if either party does not meet its obligations, but Mexico’s current deficit has led to rising tensions.
Texas lawmakers, led by Senators John Cornyn (R) and Ted Cruz (R), sent a letter to the Senate and House Appropriations pressuring them to withhold certain aid to Mexico until it fulfills some of its water obligations.
"Withholding funds will send a clear message to Mexico that the United States is serious about upholding the terms of our agreement and ensuring that our citizens and industries have access to the water resources they need. This measure will incentivize Mexico to take meaningful action to meet its obligations and resolve the ongoing water dispute" said lawmakers in the letter.
Similarly, Mexican farmers are struggling with water shortages due to continuing drought. In 2020, Mexican producers protested water deliveries by occupying a dam that sends water to the US.
According to data from the International Boundary and Water Commission, the organization that oversees the two countries' use of the Rio Grande water, Mexico has fallen short on its water deliveries since 1997. During the five-year water delivery cycle, Mexico has delivered as much water as the U.S. hopes to receive in a single year.
“They’re expanding their irrigated agriculture, and they’re killing ours,” said Sonny Hinojosa, a water advocate who serves on the board of the Rio Grande Regional Water Authority. “They’re growing crops with water that’s rightfully ours.”