US and Mexico Release Updated Colorado River Sharing Agreement
Leadership of the U.S. and Mexican Sections of the IBWC after signing Minute 334 in El Paso, Texas, on September 2, 2026. (Left to right) U.S. IBWC Secretary Sally Spener, U.S. IBWC Commissioner Chad McIntosh, Mexican IBWC Commissioner Adriana Reséndez, and Mexican IBWC Secretary Manuel Morales.
Image: USIBWC
Mexico has agreed to share the burden of recent Colorado River water cuts with the Lower Basin states. On September 2, representatives of the United States and Mexico signed Minute 334 of the International Boundary and Water Commission (IBWC), an agreement that supports cooperative management of the river’s water in the context of severe drought and record low reservoir levels. This agreement comes after the US Department of the Interior finalized a plan in late August requiring Arizona, Nevada, and California to collectively cut their water use by 1.25 million acre-feet over the next two years. In the new cooperative management plan, Mexico has accepted an annual 250,000 acre-foot cut to its allocation for the next two years, relieving some of the pressure on states to its north.
Minute 334 extends and replaces previous cooperative measures concerning the Colorado River in Minutes 323 (2017) and 330 (2024). It lays out water-sharing plans for high and low water elevations in Lake Mead, along with a Salinity Pilot Program to improve the quality of water sent to Mexico and the continuation of wetland restoration projects in the region.
For Adriana Reséndez, IBWC Commissioner for Mexico, the agreement is the result of a collaborative effort to craft sustainable water policy around the concepts of “proportionality and parity.” “Given scarcity conditions faced by the Colorado River, additional measures are needed to preserve the basin’s sustainability to benefit all users,” Reséndez said in a September 9 statement. “We will continue monitoring the evolution of basin conditions and working with interested parties to seek the best solutions during scarcity.”
Though relations between the US and Mexico have fluctuated throughout the years, the two countries have partnered on transboundary river management for over a century. The organization that would eventually become the IBWC was formed in 1889 and received its current name and formal responsibilities with the Water Treaty of 1944, which also allotted Mexico 1.5 million acre-feet of Colorado River water annually. Since 2022, Mexico has shared the Colorado River Lower Basin’s shortage reductions, in accordance with the shortage sharing framework agreement in Minute 323.
Chad McIntosh, US IBWC Commissioner, described the Minute 334 agreement as a significant hydro-diplomatic win. “Both countries deserve a lot of credit for agreeing to these water reductions and other measures,” he said.
IBWC Press Release & Copy of Minute 334
Bureau of Reclamation Press Release