No, that wasn’t a mirage. It was actually water—the Colorado River—flowing through a desert riverbed that hadn’t seen it in decades.

Thanks to an agreement, Minute 319 (pdf), between the U.S. and Mexican governments, a surge of Colorado River water was released from its floodgates down into Baja California en route to the Sea of Cortez last year. The release is referred to as a pulse, somewhat mimicking the periodic spring flows that used to run in the river. It amounted to 1% of the river’s annual flow.

The Sonoran Institute is working to rejuvenate the river banks, removing non-native plants and replacing them with those that used to thrive there before the flow stopped in 1960. “It’s kind of a no-brainer for restoration as far as ecosystems go, because it is so resilient and we’re at a point right now where we can do a lot by doing a little bit,” the Sonoran Institute’s Karen Schlatter said, according to Boulder Weekly. “We can add water and do these very no-brainer restoration efforts and get really great ecosystem response, so we get habitat established, wildlife coming back.” Thousands of cottonwood and willow tree seedlings have been planted and nonnative salt cedar removed.

The efforts are paying off. Birds not seen in 50 years, such as the yellow-billed cuckoo, are returning to the area. “When you see new birds that you haven’t seen before, you know it’s working,” Guadalupe Fonseca, a Sonoran Institute field coordinator, said, according to Al-Jazeera America. “When we plant more cottonwoods and willows, more will come….along with other new birds.”

It’s unknown how much more water will be released. The agreement in Minute 319 expires in 2017, just as the drought now underway in the West could reach catastrophic proportions. That could cause the floodgates on the Colorado to remain closed for some time.

-Steve Straehley

To Learn More:

U.S.-Mexico Water Pact Brings Life Back to Colorado River’s Parched Delta (by Tim Gaynor, Al Jazeera America)

A River Running (by Elizabeth Miller, Boulder Weekly)

Mexico Owes Water to U.S. (by Noel Brinkerhoff, AllGov)

International Boundary and Water Commission, United States and Mexico (AllGov)