San Luis Rio Colorado Flow Restoration II

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, a water sharing agreement was reached between the U.S and Mexico that paved the way for restoring flows to the lower Colorado River and its delta. Through this agreement, there is an historic 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.

Working with Pronatura Noroeste, the Colorado River Delta Water Trust and National Geographic, this work consists of a series of base flow restoration projects that restore over a billion gallons of water during the dry summer months to help restore native vegetation and habitat throughout the delta.

* Project supports voluntary transactions to change, reduce or stop water use – either temporarily or permanently – to protect or restore water for environmental benefit


Sonora, Mexico

Start Up Date:


Project Benefits:

Groundwater Conservation & Replenishment

Securing Water for Communities & Food Production

Water Quality Improvement

Wildlife & Habitat Protection

Project Type:

Flow Restoration Transaction *


Fully Funded

Project Partners

Pronatura Noroeste, Colorado River Delta Trust and National Geographic