Restoring the Colorado River Delta

This once-mighty river is drying up, but smart solutions exist

Photo of the Delta

The Colorado River has been dammed and diverted so many times that it no longer flows regularly into the Gulf of California, leaving its once-fertile Delta on life support. Despite its current state, the Delta can be restored.

Photo credit: Blue Legacy

The Colorado River as it existed a century ago, running free from the Rocky Mountains to Mexico, is a distant memory.

This symbol of the American West sustains life in the dry states through which it passes. However, healthy water flows are being compromised by current management practices and policies, as well as a warming climate and a growing Western population.

A remnant of its former self

The Colorado River Delta used to stretch over two million acres, with vast wetlands and waterways extending from the southwestern tip of the U.S. to the Gulf of California in Mexico. Life thrived in the region.


But now demand outstrips supply. The river doesn’t even reach the ocean anymore — it dries up on the U.S.-Mexico border.

Not only have plants, animals and marine life disappeared, but native people including the Cocopah and Cucapa — who have lived on the Delta for thousands of years — are now deprived of the landscape and river they used to hunt and fish.

The situation is serious, but there is good news: Efforts are underway to restore the river’s flow, including reconnecting it to the Gulf.

Two nations work together

Since the late 1990s, organizations have been working to restore the Delta with some binational government and foundational support. But until recently, they lacked the ability to acquire and manage water to restore habitat at a significant scale.

That changed in November 2012, when EDF’s Colorado River Project Director Jennifer Pitt helped federal officials from the U.S. and Mexico broker a deal to sign Minute 319 — an historic binational agreement to guide management of the Colorado River through 2017. The agreement — an amendment to a 1944 treaty between the United States and Mexico — delivers important benefits on both sides of the border to water users and the river itself.

“Now there’s a willingness to listen,” said Pitt. “For the first time, the two countries trusted each other enough to do something about this vital ecosystem.”

Significantly, the agreement allows the two nations to share Colorado River surplus water in times of plenty, and reductions in times of drought — rules that heretofore did not exist. It also lays the foundation for environmental restoration of the Delta.

A bird flies over the waters of the Cienega de Santa Clara

A bird flies over the waters of the Cienega de Santa Clara.
Photo by: Blue Legacy

EDF is working with government agencies and conservation organizations in the United States and Mexico to provide 158,000 acre-feet of water for the Delta over the next several years. With this small amount of water, approximately one percent of the river’s annual flow, we hope to physically reconnect the Colorado River to the Gulf during a limited-duration “pulse flow,” while also providing water year-round to support the restoration of 2,300 acres of forest and marsh habitat along a 70-mile stretch of river.

We are now applying lessons learned from the delta to the entire seven-state Colorado River Basin. “Flexibility is key in managing water,” says Pitt. “We’re moving away from the old framework of ‘who gets what’ and instead establishing cooperative river management whereby countries work together to achieve desired outcomes, both for water users and for the environment.”

Changing how the West views water

We are launching an ambitious plan to reform management along the entire length of the Colorado River. Bringing together groups that have not always cooperated with each other, we want to reduce pressure on the river by:

  • Protecting and restoring healthy flows for rivers throughout the Colorado River Basin. We need to determine the amount of water the Colorado River system needs to remain healthy and revive natural seasonal floods and low flows.
  • Creating incentives that promote conservation and efficiency in cities.
  • Ensuring that agriculture remains vital in this region, while creating incentives for ranchers and farmers to modernize irrigation infrastructure that increases their productivity and allows them on a voluntary basis to share the saved water with other users.

“Irrigated agriculture in the West uses up to 80% of surface water, and this is not sustainable,” says Pitt. “EDF is working on solutions that allow ranchers and farmers to prosper and at the same time maintain viable rural and urban communities as well as healthy rivers.”

In untangling the web of competing water interests, our partnerships with The Nature Conservancy, Trout Unlimited and local conservation groups will be pivotal.

Flexibility is key in managing water.

Jennifer Pitt Director, Colorado River Project

With the river already over-allocated and populations growing, there’s no time to lose. Reservoirs along the Colorado River are already barely half full, and as scientists have gotten better at assessing regional impacts of climate change, they predict a further 10-15% decline in its flows by midcentury.

Still, we and our partners remain hopeful. “A new generation of Western water managers is looking at water differently,” says Pitt. “They understand the way to keep rural economies strong is to maintain the health of the river ecosystems.”

“We are helping update water management to the realities of the 21st century. If we don’t do this right, we risk losing some of our nation’s most iconic ecosystems.”

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Healthy flows for the Colorado River Basin

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  • 36 million

    people depend on the Colorado River for their water supply