By Joanne Littlefield
As it churns its way through the arid West, people, wildlife, vegetation, and aquatic creatures depend on water from the Colorado River. Dammed throughout its length and used for recreation and power, the river also is tapped and siphoned for the agricultural and developmental uses of an increasing population. It is estimated that 25 million people in the Southwest rely on it.

For the first time in history, however, users are facing serious shortfalls and the potential that the river won't be able to meet our needs, says Kathy Jacobs, manager for a University of Arizona research project on the role of climate information in water management decisions.

The U.S. Bureau of Reclamation is responsible for regulating Colorado River water in the lower basin — the span that traverses Nevada, California and Arizona — and decides when to release water into Lake Powell and Lake Mead. Tops on the agenda is how the various states use and share water in times of shortages. UA researchers are helping the Bureau of Reclamation integrate new types of information into their river model, says Jacobs, executive director of the Arizona Water Institute. "Having a little bit more information about what is likely to happen in the next few years is of huge value to them."