Day 5: Mexico-U.S Water Agreements, Colorado Delta, Wetlands Restoration

Morelos Dam
Good Rivers Make Good Neighbors? The U.S., Mexico, and the Colorado River

It’s fair to say the United States and Mexico have had better relations than they’re having now, and plenty of evidence can be found by looking at how the two nations work together on the Colorado River. Through a treaty signed in 1944 and updated numerous times, Mexico is entitled to 9 percent of the Colorado River’s water. Most of that water is diverted at the Morelos Dam and fuels agriculture in the Mexicali Valley, and much has been made of the fact that the Colorado River is so oversubscribed before it even reaches Mexico that it no longer reaches the Gulf of California. Minute 323, which became finalized in late 2017, is a commitment by the U.S. and Mexico to work together to solve water scarcity issues through 2026. It calls for Mexico to leave more water in Lake Mead and the U.S. to fund $31.5 million in water conservation projects in Mexico. It also sets a goal of increasing the 1,000 restored acres of riparian habitat in Mexico more than four-fold, continuing the restoration of the Colorado River Delta. We heard about the background of this agreement, the on-the-ground impacts, and how it’s imperative that the two countries continue working together.

Laguna Grande

Some 70 miles of riparian habitat still exist along the Colorado River in Mexico (even though the water’s gone), and a 2014 “pulse flow” that sent water all the way to the Gulf of California revived a long-desiccated river corridor. Beginning in 2006, the Sonoran Institute and partner ProNatura Noroeste began the work of establishing a 1,200-acre nature preserve along the river. So far the Sonoran Institute and its partners have restored more than 1,000 acres and planted more than 200,000 trees; its largest restoration site is Laguna Grande. We hiked through the site and heard about restoration efforts, community involvement, and future plans.

La Ciénega Santa Clara

La Ciénega Santa Clara began as a happy accident, when water too salty to deliver as Mexico’s allotment of fresh water was diverted through the 60-mile-long Wellton Mohawk Irrigation Canal and dumped on dry ground that was once the eastern part of the Colorado River Delta. That water has flowed for more than 45 years now at a rate of roughly 100,000 acre-feet per year, creating the largest wetland in the Lower Colorado basin at more than 40,000 acres. It’s home to thousands of birds and a critical stop along the Pacific Flyway. But with every drop of Colorado River water under scrutiny, talk of firing up the desalination plant in Yuma just won’t go away. Doing so would deprive La Ciénega of its water source and could undo decades of habitat restoration. We visited the wild moonscape that is the Colorado delta, and ventured aboard boats for a quick tour of the wetlands.