The flow of the Rio Grande River on the U.S.-Mexico border has been fundamentally changed by the buoys placed to deter migrants from crossing illegally, according to preliminary findings by Southern Illinois University Edwardsville researchers.
“The buoys are changing where flow is occurring, and anytime you change where flow is occurring, you’re changing where erosion and deposition are occurring,” said Adriana Martinez, a professor of geography and environmental sciences at SIUE and a native of Eagle Pass, Texas. “Ultimately, that’s going to change the channel shape in that spot.”
Martinez and third-year SIUE student Emma Prott have been studying the effects of the buoys placed by Texas in July 2023, which have been the subject of a legal battle between the state and federal government over who has authority over the southern border.
The SIUE professor and student visited the Rio Grande at Eagle Pass twice over the past two months, capturing drone images and collecting sediment samples to document and quantify how the buoys change the river.
The researchers say long-term implications of the river’s ecology are at question.
So far, water flow around the buoys has slowed down, causing sediment to build up underneath them. The shallower water has meant plants have started growing. As more plants grow, more sediment is displaced, setting off what Martinez calls a “chain reaction.”
“It's going to change the international boundary,” Martinez said. “We could add land to the U.S. and take it away from Mexico or vice versa. It just depends on what ends up happening more long term or how long the buoys are in place.”
Martinez believes the buoys will create a sandbar and eventually a small island in the middle of the Rio Grande.
Prott, a native of Marine, Illinois, 10 miles east of Edwardsville in the Metro East, said her trips to the border have been an eye-opening experience.
“A lot of people that don't live near the border, or live far away from it, don't even think about it,” said Prott, who’s studying environmental sciences. “These are real people that have real stories, and I think visiting definitely humanized it a lot better.”
On their November trip, Prott said they didn’t observe any migrants crossing the border.
What she did notice was the stark difference between the U.S. and Mexican sides of the river. The U.S. border has been militarized with concertina wire and fences, Prott said. Since learning the buoys have altered the river’s flow, Prott said she believes the overall approach is an ineffective way to deter illegal immigration.
“I don't think people need to get hurt to probably inhibit that or slow it down,” she said. “There's better ways. I'm not really sure what they are, but I don't think people should be getting hurt over this.”
Texas officials have argued the buoys are a low-cost effort to prevent illegal immigration in Eagle Pass, a hotspot for crossings. Gov. Greg Abbott recently placed more buoys in the river, despite the ongoing lawsuit.
The SIUE researchers hope to publish their findings in a paper in the next couple of years, but there’s more work to be done, Martinez said. Prott, who’s staying on next semester, said she’s interested in studying the border more in graduate school.
In the meantime, the two said they want to continue their work to educate the public because access has been cut off to the river.
“Somebody's watching the river,” Martinez said. “Somebody's looking at what's happening, and someone's trying to study what effect the buoys are having.”
