Climate Disruption in the West: The Colorado River

About 30 million Westerners -- nearly one tenth of all Americans -- depend on the water of the Colorado River, most of which originates as snowfall in the Rocky Mountains. The river's water is used in seven states (California, Arizona, Colorado, Nevada, New Mexico, Utha, and Wyoming); the largest city in each of those states (Los Angeles, Phoenix, Denver, Las Vegas, Albuquerque, Salt Lake City, and Cheyenne); and 22 of the 32 cities in those states with populations over 200,000. Many of them are also among the fastest growing cities in the country.

No wonder the U.S. Department of the Interior says the Colorado River is the most important natural resource in the southwestern United States.

This valuable resource is highly vulnerable to an altered climate. One study of climate change impacts in the Colorado River basin, published in January 2004, illustrates what climate change can mean to the West. The researchers used a climate model developed by the National Center for Atmospheric Research, which predicts less drastic outcomes than many other climate models – leading the researchers to call this a “best case” prediction for the Colorado River basin. However, those predictions are hardly reassuring.

“What this work shows is that,
even with a conservative climate model,
current demands on water resources
in many parts of the West will not be met
under plausible future climate conditions –
much less the demands of a larger population
and a larger economy.”

T. Barrett, et al.,"The Effects of Climate Change
on Water Resources in the West: Introduction and Overview," Climatic Change (2004).