Colorado River

The River Runs to It…Again

Stand with Us to Protect the Colorado River

Nearly 36 million people rely on the Colorado River for water, food, recreation and energy.


A Pulse of Life for the Delta

The Conservancy is excited to be part of an historic event as the U.S. and Mexico release water into the Colorado River Delta.


"There is great promise for healthy rivers throughout the Colorado River Basin and around the world."

- Taylor Hawes, Colorado River Program Director

The mighty Colorado River carves out dramatic canyons through the rocky terrain of the southwestern United States, but it has not reached the sea in the Gulf of California in decades—until now. Dams and diversions along the river’s winding path have left little or no water for the region south of the Mexican border known as the Delta. 

On Thursday, May 15, during high tide, the river once again connected to the Gulf of California following a release of water on March 23. 

The water release—known as a “pulse flow”—is part of the bi-national agreement between Mexico and the U.S. designed to mimic a regular spring runoff and bring life back to the Colorado River Delta. The water was freed by conservation projects in Mexico, which made the water available for this release. The treaty amendment between the two countries also outlines how the United States and Mexico will share and store water in times of drought and surplus. 

Update: Scientists Say Pulse Flow Showing Success

“This is about a sustainable future,” says Taylor Hawes, the Conservancy’s Colorado River program director. “By beginning to restore the delta, we are demonstrating that there is great promise for healthy rivers throughout the Colorado River Basin and around the world.” 

That promise is proving true as people in the communities along the Delta rejoiced when water filled the once-parched riverbed. Children splashed while others jumped in their kayaks for fun. Frogs were seen jumping toward the water’s edge and the seeds of native trees that had laid dormant for years began sprouting in weeks. Watch a slideshow that documents the return of water to the river.

No one really knew what kind of impact the water would have on the delta. Conditions are quite different from the last time water regularly flowed in this region, around 50 years ago. Despite the existing scientific knowledge, it was very difficult to predict the environmental effects of the pulse flow. 

The science team that designed the flow—including the Conservancy’s Eloise Kendy—was aiming for healthy, self-sustaining cottonwood and willow trees to take root that would be enjoyed by flocks of local and migratory birds. The fact that the water reconnected with the sea—even if for a short time—was an incredible surprise!  

“This is what all of us scientists hoped, but never dared to predict, would happen,” said Kendy, a Conservancy hydrologist. 

Now, scientific monitoring is underway. If the historic experiment is successful, the Conservancy and its partners hope to be able to do this kind of release more regularly in the future, which could also generate rural economic activities and job opportunities for local people including river restoration, tourism and commercial fisheries.