U.S.-Mexico water treaty under scrutiny as drought persists

HOUSTON – The Houston Chronicle reports farmers in South Texas celebrated earlier this month when the Trump administration announced it had struck a deal with Mexico to increase water releases into the Rio Grande. But it was nowhere near what Texas farmers were owed. With drought ongoing on both sides of the border — conditions that are only expected to worsen with climate change — the future of the more than 80-year-old treaty governing water rights between the two countries appears increasingly unstable. Some Texas lawmakers say it’s time to redraw the terms of the deal so Mexico has to release water more frequently. The river’s water is use to sustain a more than $800 million farming industry in South Texas that ships grapefruits, onions and other produce around the country.

“This has been a longstanding problem,” U.S. Sen. John Cornyn said in an interview earlier this month. “The timing of water is critical to our farmers, so it doesn’t do much good to get it at a time when frankly they don’t need it as much.” There’s still a looming question about how much water will even be available to send. Scientists are projecting that not only will rainfall in South Texas and northern Mexico decline slightly in the decades ahead, but rising temperatures caused by climate change will increase evaporation rates, reducing the amount of water that ends up in the Rio Grande. “The Rio Grande is the most vulnerable river in Texas to climate change,” said John Nielsen-Gammon, the Texas state climatologist. “When we look at projections, in most months the stream flow decreases. There’s going to be months, one or two or four per decade, where the intensity in the rainfall increases the flow, but that’s more erratic, which isn’t good for farmers.” The recent deal negotiated by the Trump calls for the release of more than 50,000 acre feet of water controlled by Mexico from the Amistad dam, along with an increase in water flows into the Rio Grande from seven tributaries on the Mexican side of the river, said Brian Jones, a farmer in Edcouch who sits on the board of the Texas Farm Bureau.