San Luis Rio Colorado II

Sonora, Mexico (Colorado River Delta)

PROJECT PARTNER(S): Pronatura Noroeste, Colorado River Delta Trust and National Geographic
PROJECT TYPE: Water Management Agreements


Once one of North America’s great desert ecosystems, the Colorado River Delta at one time provided millions of acres of freshwater, wetland, tidal and brackish habitat supporting hundreds of fish and wildlife species. This dynamic and diverse ecosystem supported indigenous human populations for thousands of years, and today it still provides critical habitat for over 350 species of birds.

However, because historical treaties between U.S. states and Mexico allocated no water to sustain the river ecosystem, the Delta has been desiccated and decimated, with its once extensive wetlands now covering only a tiny fraction (~5%) of their historical 2 million acres. In fact, in most years the mighty Colorado River no longer even flows to the sea.

In 2012, an historic water sharing agreement was reached between the U.S and Mexico that paves the way for restoring flows to the lower Colorado River and its delta. Through this agreement, there is now the opportunity to restore water to the desiccated lower Colorado River Delta with the promise that restored flows may someday support thousands of acres of wetland and river habitat.

The new agreement provides a landmark opportunity for restoration of the delta ecosystem. BEF, working with Pronatura Noroeste, the Colorado River Delta Water Trust and National Geographic, has supported several WRC pilot projects that collectively restore over a billion gallons of water to help revitalize critically dewatered areas of the delta. This water is used to restore native vegetation and habitat in wetland and riparian areas—and also supports some of the first ever restored river flows through the delta ecosystem.

Many more investments from myriad other funders and partner organizations will be needed to achieve the long-term flow restoration goals in the delta. However, BEF and our partners in this project are incredibly proud to play an early and critical role in restoring water to this once great ecosystem. Restoring flow now to the delta is a critical first step, and as we succeed in enlisting support from additional businesses and corporations through BEF’s Water Restoration Certificate® program, we expect to make additional investments in restoring Colorado River flows through the delta.

*This resource has been reviewed and found to meet the BEF Flow Program Certification Criteria for Evaluating Proposals to Secure Environmental Flows by the National Fish and Wildlife Foundation.