When two countries – the United States and Mexico – share one river – the Colorado River – it requires almost continuous binational collaboration. Our two countries have a long history of collaboration and cooperation related to the river, as we share both the risks of drier future and the opportunities to jointly develop innovative solutions to our shared challenges. 

The recently completed “Binational Study of Water Desalination Opportunities in the Sea of Cortez” is another example of binational collaboration with the goal of developing new, collaborative solutions together. This study represents an important step forward as the U.S. and Mexico explore joint solutions to protect the Colorado River and augment our shared water supply.

The Binational Desalination Work Group, composed of United States and Mexican federal, state, water agency and non-governmental organizations, was created as part of Minute 323, an implementation agreement of the 1944 Water Treaty, administered through International Boundary and Water Commission. The Work Group was co-chaired by the Sonoran Water Commission and the Arizona Department of Water Resources. 

The Mexico and U.S. participants jointly developed a detailed scope of work to implement the study. CAWCD volunteered to procure consultants to implement the binational project.  Ultimately, the work group, with the guidance of the CAWCD procurement team, selected the binational engineering team of Black and Veatch plus Libra to conduct the study.  All meetings were conducted in English and Spanish, and all work products were provided in both languages.  CAWCD, along with ADWR, SRP, Freeport McMoran, California parties and SNWA, funded the study on behalf of the binational effort, while Mexico participants provided important research and studies. 

The study, conducted from fall 2018 to spring 2020, identified several seawater desalination opportunities along the Sonoran coast of the Sea of Cortez to benefit both countries, while respecting the environmental integrity of the region. The opportunities, if developed, could augment up to 200,000 acre-feet per year of water to benefit Colorado River water users in Mexico and the United States.

Next steps, taken over the next several years, will be to jointly explore a binational exchange framework, rights-of-way, power availability and the scope and size of a potential site.

The study represents deeper collaboration between Mexico and the United States in our attempt to jointly augment the shared resources in the Colorado River.  The study is the first step in potentially developing new supplies to address the shared risks of a drier future while providing benefits to water users in both countries. For more information, visit CAP’s desalination web page.