How the water treaty creates a new tension between Mexico and the US

Colorado River 

The 1944 Water Treaty, officially titled the treaty to the Utilization of Waters of the Colorado river and Tijuana  and of the Rio Grande rivers, is a landmark agreement between the United States and Mexico that governs the distribution of water from key shared rivers.

 Signed on February 3, 1944, this treaty has played a crucial role in managing water resources between the two nations for decades, until the 90s when Mexico experienced severe drought. 

Background 

 The beginning of the 20th century saw growing tensions between the U.S. and Mexico over water usage from rivers that cross or define the border, particularly in the arid regions of the Southwest.

Agriculture  and urban development expanded, so did the demand for reliable water supplies. Both countries recognized the need for a formal, equitable agreement to avoid conflict and ensure sustainability.

Key Provisions

The treaty outlines how water from three major rivers—the Colorado River, the Tijuana River, and the Rio Grande—is to be allocated:

• Colorado River: The U.S. agreed to deliver to Mexico a guaranteed annual quantity of 1.5 million acre-feet of water, with provisions for additional deliveries in times of surplus and reductions during extraordinary drought.

• Rio Grande: From Fort Quitman, Texas, to the Gulf of Mexico, the river’s water is divided based on contributions from tributaries in both countries. Mexico delivers an average of 350,000 acre-feet annually from six Mexican tributaries, while the U.S. provides water from the Pecos and other tributaries.

• Tijuana River: The treaty acknowledged the need for cooperation but left some specifics to be addressed later through implementing

Challenges

Climate change, population growth, and prolonged drought have tested the treaty's resilience. Periodic tensions arise—particularly over Mexico’s obligations to deliver water from Rio Grande tributaries—but the treaty has generally endured, thanks in large part to ongoing diplomatic cooperation and flexible management.

In recent years, both countries have signed minutes—supplementary agreements under the treaty—to address current issues, such as Minute 319 and Minute 323, which focus on environmental restoration and water conservation in the Colorado River Delta.

The situation now 

2020- 2025 cycle Mexico delivered only one year's worth of the water(400.000) acre feet, the US started pressure by suspending the USAID. 

Last march , the Trump administration refused to deliver water to Mexico for the first time, and threatened to apply the new tarrifs if Mexico failed to deliver its share.

Conclusion

The 1944 Water Treaty remains a model for international cooperation on shared water resources. Despite the challenges of a changing climate and increasing demand, it provides a legal and diplomatic framework that has helped the U.S. and Mexico navigate one of the most critical aspects of their bilateral relationship: water.