With new administration, is decades-old treaty with Mexico in danger?

1944 Treaty stipulated how Mexico, U.S. would share water

AMISTAD RESERVOIR – The United States’ relations with Mexico continues to sour as President Donald Trump pushes back on issues like immigration. However, for places like Texas, water also remains a point of contention for the two countries.  

"This is a bad deal for the United States,” said Texas Rep. Lyle Larson, of San Antonio, who also serves on the Southwestern States Water Commission.  

With changes underway in Washington, Larson believed it might be time to tighten the screws on the country’s southern neighbor. 

"We've taken them all the way to The Hague in International Court to resolve this matter, and we can't get it done,” said Larson. 

The battle over water between Mexico and the United States is not new. A 1944 treaty, stipulating how water that flowed down the Rio Grande would be shared, has long been a point of contention.

"We're always compliant; 100 percent compliant for the last 50 years,” said Larson.

Mexico, however, who is obligated to release 350,000 acre feet annually into Rio Grande through other tributaries, has built up a debt. Some of that water debt was recently repaid to the United States, but not all. The lack of water can become evident in places like Lake Amistad.

"That lake will drop sometimes 50 ft., because the people in Mexico aren't releasing the 350,000 acre feet of water,” explained Larson.

As Rio Grande water flows south from Amistad Dam to Falcon Lake and eventually the Rio Grande Valley, if there is a deficit, it affects all of those who need the water all along the way.

"Del Rio, Eagle Pass, Laredo, all the way down to Brownsville,” Larson said, listing those affected.

Larson’s solution, if Mexico does not release its share into the Rio Grande, would be to hold back water from the Colorado River in the western United States.  Not to be confused with the Colorado River in Texas, it is a major river that feeds Lake Mead near Las Vegas.  It, too, is part of the 1944 Treaty and provides water to Mexico. 

Should that not work, Larson said he would recommend dissolving the agreement.   

"The only thing we can do is walk away from the treaty,” said Larson. 

In a recent commentary in the McAllen Monitor, a south Texas newspaper, United States Commissioner of the International Boundary and Water Commission Edward Drusina voiced opposition to Larson’s views of withholding water. Drusina said that such a move would “usher in an era of conflict that would harm water users in both countries and could spell the end of the treaty itself.”

About the Author:

Justin Horne is a meteorologist and reporter for KSAT 12 News. When severe weather rolls through, Justin will hop in the KSAT 12 Storm Chaser to safely bring you the latest weather conditions from across South Texas. On top of delivering an accurate forecast, Justin often reports on one of his favorite topics: Texas history.