A new study finds that there is a 50-50 chance all of the Colorado River reservoirs — in California, Arizona, Nevada, Utah, and Arizona — will run completely dry by the year 2057 if currents trends and practices continue.
The study looked at a range of possible scenarios regarding stream flow and reservoir levels and identified that different management practices could prevent reservoirs from running out of water by this time. They also modeled climate change using current trends and population changes. The lead author of the study, Balaji Rajagopalan of the University of Colorado in Boulder, says, “water managers should begin to re-think current water management practices during the next few years, before the more serious effects of climate change appear.”
Currently, about 30 million people rely on these reservoirs for drinking water and irrigation purposes. The population has swelled in recent decades in these areas. Population growth in these areas is another factor that will increase the chance that the reservoirs will run dry by this time. However, population growth will have a much smaller impact than water management practices and climate change, according to the study.
According to Rajagopalan, “On average, drying caused by climate change would increase the risk of fully depleting reservoir storage by nearly ten times more than the risk we expect from population pressures alone.” The risks of running dry due to management practices remaining the same is seven times greater than the risks from population growth, according to this study.
The drought causing the Colorado River to run dry started 10 years ago. At that time, the reservoirs were at about 95% capacity. Due to this and the fact that the reservoirs can store over 60 million acre feet of water, there is not serious threat of the reservoirs running dry until 2027.
The biggest recommendation from the authors of the study is that water management practices must change now to address concerns about the future.
For more information on the study, which will soon be published in Water Resources Research, click here.
Image credit: Wolfgang Staudt via flickr under a Creative Commons license.