Colorado River Water Demand Rises

The San Juan River carries New Mexico’s share of the Colorado River Basin’s water, which is under increasing pressure from declining flows and growing population. Photo Credit – Journal File

With population growth pushing up Colorado River Basin water demand as climate change pushes down supply, New Mexico and the other states that depend on the river face a growing gap between how much water nature provides and how much humans want to use.

New Mexico’s population that uses the river’s water, currently nearly 1.5 million people, is expected to grow to between 2 million and 3 million by 2060, according to the latest data from a U.S. Bureau of Reclamation study.

The San Juan River, a tributary of the Colorado, provides water in northwest New Mexico. In addition, the Bureau moves water through a tunnel beneath the continental divide, providing Colorado Basin water for Santa Fe, Albuquerque, and other residents of the Rio Grande Basin.

“It’s an important part of our water supply,” said David Jordan, a hydrologist with the Albuquerque office of INTERA, a water resources consulting firm.

Across the western United States, nearly 40 million people live in the region that gets its water from the Colorado. By 2060, that is likely to rise to between 50 million and 75 million, according to the bureau study.

“It’s just astounding how many people depend on it,” Estevan López, head of the New Mexico Interstate Stream Commission, said of the river system that snakes from the northern Rocky Mountains to the Gulf of California.

The amount of water it carries is declining. Flows are expected to drop 9 percent by 2060 as climate change, caused by rising greenhouse gases, raises temperatures and shifts rain and snow patterns, according to the Bureau of Reclamation.

Supply exceeded demand in the basin the late 1990s, and the region’s water users have met their needs in the years since by drawing down reserves stored in the river system’s big reservoirs, bureau data shows.

The biggest pressure is on California, Nevada and Arizona, López said. The risk is that those states might try to come after New Mexico’s water, he said in an interview.

“They’ll be looking, potentially, at our supply,” he said.

Absent changes in the law, the Colorado River water now used by Albuquerque and other Rio Grande Valley communities should be safe, Jordan said. The risk for New Mexicans, he said, would be a change in river management policy that calls for basin shortages to be shared by all the states. No change like that is currently contemplated by the basin’s leadership, but the idea is often suggested by Pat Mulroy, head of the water agency that serves water-short Las Vegas, Nev.

The new study is the most comprehensive effort in decades to quantify how much water there is in the basin and how much its residents will need in the future. Its purpose is not to suggest any particular solution, according to Carly Jerla of the Bureau of Reclamation, who is leading the effort. Rather, its goal is to lay out options for later use.

As part of the study, the bureau solicited suggestions for reducing the supply-demand imbalance. Ideas ranged from conservation and growth controls to the bizarre: towing icebergs south from Alaska. The icebergs would be dragged to a port on the California coast where the water could be melted and pumped to western water users, according to the anonymously submitted idea.

Among the most popular suggestions for adding water to the basin are canals or pipelines – from the Snake River in Idaho, the Columbia River between Oregon and Washington or the Mississippi.

Such ideas are unlikely to be practical, not only because of cost but more importantly because people in other parts of the country are unlikely to be willing to part with their water for our use, said Denise Fort, a University of New Mexico professor and co-author of a recent study of large scale water transfer proposals.

“There are very few areas of origin that regard their water as surplus,” Fort said in an interview.

Michael Cohen of the Pacific Institute, a California-based think tank, said the situation may not be as grim as the preliminary bureau data suggests.

With the real estate collapse, growth in Western cities is likely to be less than the bureau is projecting, he said. In addition, efforts in Albuquerque and other cities across the region have demonstrated greater room for water conservation than is currently considered in the bureau’s analysis.

Cohen is concerned that supersized estimates of the river’s supply-demand gap may force the region to pursue expensive solutions to a problem that may not be as large as the latest data suggests.

“It kind of creates this climate of crisis,” he said in an interview, “that we’re all doomed if we don’t divert the Mississippi River.”