For the first time in 16 years, the Colorado River will flow all the way to the Gulf of California -- thanks to a temporary release of water in March designed to mimic the river’s natural spring flood phase.
Scientists monitoring the flow expect the two waters to meet during high tide on Thursday. It will be the first time water from the Colorado River has completed its journey to the Upper Gulf of California since 1998.
"It is invigorating to know that water from the Colorado River will reach its natural end," said Jennifer Pitt, Colorado River Project Director at Environmental Defense Fund (EDF). "We've been missing that connection for a long time. The prospect of the river completing its journey and reconnecting with the sea signals that, if only briefly, a fundamental disruption of nature has been made whole again."
The temporary release of water initiated on March 23 -- known as a "pulse flow" -- began at Morelos Dam, which straddles the Colorado River on the international border west of Yuma. When the gates of the dam were opened from March 23 - May 18, 105,392 acre-feet of water -- about 0.7 percent of the amount of water flowing through the river channel annually -- swept downstream into the long depleted Colorado River Delta.
The pulse flow lasted about eight weeks in total, bringing much needed relief to the habitats and communities in the delta region, according to EDF.
The pulse flow was made possible by Minute 319, an "exemplary water-sharing agreement between the United States and Mexico to provide multiple benefits for water users on both sides of the border," EDF officials said.
In addition to the pulse flow, the policy framework more broadly allows the U.S. and Mexico to share surpluses in times of plenty and reductions in times of drought, provides incentives for leaving water in storage, and conserves water through joint investments in projects from water users in both countries, EDF officials said.
"The pulse flow goes beyond the Colorado River Delta," Pitt said. "It represents a model for dealing with a changing climate in water stressed regions globally."