It’s time to restore the Colorado River

For decades, broad coalitions of government agencies, nongovernmental organizations, resource users and ordinary citizens have worked together to restore and protect some of the great aquatic ecosystems in the United States, including places such as the Chesapeake Bay, the Great Lakes and the Everglades.

For the Great Lakes, those efforts reflect our shared responsibility for that internationally significant complex of lakes and rivers, and the reality that ecosystems do not respect artificial borders. Those efforts all recognize the tremendous services provided by large aquatic ecosystems, including obvious economic resources such as fish, shellfish, water supply and recreation, as well as less apparent services such as filtering of pollution, flood control, cycling of nutrients, and the sheer intrinsic and spiritual value that have always drawn people to the water’s edge.

Notably absent from that laudable set of programs is a comprehensive, watershed-wide effort to restore the badly damaged ecosystems of the Colorado River, including its globally significant complex of wetlands and estuaries within the Colorado River Delta in Mexico. Several regional efforts are under way with a goal of addressing harm to smaller components of the Colorado River within the United States. To date, however, none of those efforts has demonstrated significant success, and none has received anywhere near the level of federal funding or support as programs in other parts of the country. Nor do any of those programs recognize U.S. responsibility to work with Mexico to restore and protect this international ecosystem.

Why has the Colorado River not commanded the same attention as large aquatic ecosystems such as the Chesapeake Bay or the Everglades? It certainly cannot be because it is any less significant ecologically. The Colorado River’s unique hydrological and ecological conditions once supported one of the world’s largest percentages of endemic fish, species found nowhere else on the planet. In its lower reaches and in the delta, the river spilled over a broad floodplain, nourishing thousands of acres of wetlands that hosted lush vegetation and a bounty of waterfowl and other wildlife.

The real reasons for the relative lack of attention to restoring Colorado River ecosystems have more to do with how we have viewed and treated the river for the past century or more. Although there were some commercial fisheries in the Colorado for brief periods of time, for the most part we treat the Colorado River as a huge bucket from which to draw water for non-ecological uses in other parts of the basin and beyond, and as a source of electricity to power city lights and air conditioners.

We value the river’s natural features mainly for recreational and aesthetic reasons, such as thrilling rides through the rapids of the Grand Canyon, and not for the unique species of fish that once thrived there or the hundreds of species and birds and wildlife that depended on the narrow riparian oasis threaded through the Sonoran Desert and into the Sea of Cortez.

The Colorado River’s artificial plumbing system contributes immensely to the human economy and lifestyle in the arid Southwest. But those benefits come with a serious price. Hundreds of miles of former flowing river now lay below artificial reservoirs, and the dams fragment the river both physically and biologically. In most places, spring flood flows are significantly smaller and flows from the dams are much higher and more uniform during other parts of the year. Especially below the Hoover Dam, hundreds of miles of river channel are imprisoned within levees or constrained by artificially fortified banks.

Water released from the dams is typically much colder and more uniform in temperature than in the natural river, and is starved of the sediment and nutrients that once flowed downstream and provided sustenance and habitat for native fish. Water quality has deteriorated due to direct releases of sewage and industrial waste; and polluted runoff from farms, roads, mines, mining wastes and other sources adds salts and other contaminants. We also introduced dozens of non-native species, some intentionally and others by accident, which prey on and out-compete native species.

As a result, once-thriving populations of endemic fish are now gone from parts of their former range. The U.S. Fish and Wildlife Service has listed four species of fish — humpback chub, bonytail chub, razorback sucker and Colorado pikeminnow — as endangered. Riparian communities once dominated by cottonwood, willow and other native plants are now overrun by tamarisk (salt cedar). For hundreds of miles, levees and other structures separate the river from its natural flood plain; reduced flows have eliminated the river’s natural spring overflows. Birds and other species that once thrived in those habitats, such as the southwestern willow flycatcher and the Yuma clapper rail, are endangered due to the loss of riparian habitat.

Nor have we accepted our international obligation to this shared ecosystem, as we have with Canada for the Great Lakes.

More than a century ago, U.S. Attorney General A.G. Harmon argued that the United States had no legal obligation to ensure that Colorado River water flowed into Mexico, thus allowing us to use the entire river within the United States. The United States formally abandoned that questionable doctrine in 1944 when it signed a treaty guaranteeing Mexico about one-tenth of the average amount of water that once flowed past the international border.

Mexico shares some of blame for the river’s plight because most of that water is diverted for irrigation and urban use south of the border, robbing the Colorado River delta ecosystem of the flows of water and nutrients necessary to sustain its former health and ecological productivity. And the U.S. government clings to remnants of the Harmon Doctrine by claiming that environmental laws such as the National Environmental Policy Act and the Endangered Species Act do not apply to U.S. actions that affect the Colorado River and its ecosystems in Mexico.

It is time to reconsider our policy toward the Colorado River, and to accept our shared obligation to protect this international ecosystem. Efforts to restore the Colorado River deserve the same level of support as the Chesapeake Bay or Everglades restoration programs, and the same international focus as the Great Lakes Initiative.

To do so, we must first abandon our vision of the Colorado River as nothing more than a giant bucket of water, and recognize it as one of the world’s great aquatic ecosystems.

Robert W. Adler, author of “Restoring Colorado River Ecosystems: A Troubled Sense of Immensity” (Island Press 2007), is associate dean for academic affairs and James I. Farr chair and professor of law at the University of Utah, S.J. Quinney College of Law.