On Nov. 9, the International Boundary and Water Commission (IBWC) signed a new agreement aimed at ensuring more regular water deliveries between Mexico and the United States. Minute 331, titled "Measures to Improve the Reliability and Predictability of Rio Grande Water Deliveries to Benefit the United States and Mexico," provides Mexico with tools and flexibility to deliver water earlier in the five-year cycle established under the 1944 US-Mexico Water Treaty.
A key feature of the agreement allows Mexico to use the tools to reduce or prevent shortfalls in water deliveries to the United States, subject to prior US agreement. The Minute, which comes amid growing water scarcity on both sides of the Rio Grande, recognizes the importance to the United States of incorporating Texas water deliveries in the annual allocation plans of Mexico's water managers. Some of the agreement's pilot programs will end after five years unless the two governments choose to extend them.
The agreement benefits both the United States and Mexico, providing options for avoiding the recurring crises at the end of five-year water cycles. It is the result of over 18 months of negotiations, and a binational initiative dating back to October 2020. At that time, the United States and Mexico signed Minute 325, successfully concluding a five-year water cycle without a deficit, while committing both governments to developing a new Minute to ensure more predictable and reliable water deliveries.
In addition to provisions related to water deliveries, Minute 331 establishes a Rio Grande Environment Work Group to address environmental aspects in the international reach of the Rio Grande. It also formalizes the Lower Rio Grande Water Quality Initiative to address water quality concerns, especially salinity.
Over the longer term, the two governments expect a Projects Work Group created under the Minute to develop water conservation projects for the benefit of both countries, as has been done successfully in the Colorado River basin. Under the 1944 US-Mexico Water Treaty, Mexico delivers water to the United States in the Rio Grande in cycles of five years, for a minimum annual average of 350,000 acre-feet, except in the event of extraordinary drought or serious accident to its water infrastructure. During the current cycle, which began on October 25, 2020, Mexico has delivered a total of 425,405 acre-feet. Mexico's obligation under the treaty is to deliver 1.75 million acre-feet by October 24, 2025, absent extraordinary drought or a serious infrastructure accident.
