Extensive research on the impacts of climate change on the snowpacks of the Colorado River Basin has created a clear vision of the current future that is being witnessed today: lower water flows, more drought. While residents, institutions and governments in California, Nevada, Arizona and New Mexico race to adapt to these impacts, many headwater communities and state governments refuse to acknowledge the reality of climate change.
Megadrought in the Colorado Basin?
The Colorado River Basin provides water to millions of people in 7 states. Over 80 percent of the Colorado River Basin’s flows come from snowmelt and mostly from the headwater states of Utah, Colorado and Wyoming. These headwater states comprise just 1/7th of the watershed but produce 6/7th of the Basin’s water. This is why headwater snowpack is critical to so many Western residents. Unfortunately, increased air temperatures are expected to lower Colorado River streamflows by 9-30 percent in coming years.
Droughts events are more likely to occur in the future as the American Southwest is likely to see a long-term drying period with lower precipitation levels. Many are calling this new era a “megadrought” which could be particularly difficult for the Colorado River Basin where streams are already under great duress during summer months. Low elevation watersheds stand to suffer disproportionately from a “megadrought” because of the reduced volume of snowpacks expected at lower elevations.
Other states and communities refuse to reduce excessive water use among metropolitan users, regardless of the impacts on downstream communities that are more conscientious of their water use. Some urban residents in Southwestern Utah, for example, use two to three times the water use of Albuquerque residents (per person) even though both communities rely on flows of Colorado River water.
Headwater communities must reduce their municipal water use through basic water conservation programs that downstream communities in Las Vegas, Los Angeles, Phoenix and Tucson achieved decades ago.
Read more about climate change impacts in the Colorado Basin at the links below.
- Effects of a Carbon-Dioxide Induced Climate Change on Water Supplies in the Western United States. Roger Revelle and Paul Waggoner, 1983.
- An Assessment of Severe and Sustained Drought in the Colorado River Basin. Donald Kendall and John Dracup, 1990.
- The Colorado River Basin and Climate Change. Linda Nash and Peter Gleick of Pacific Institute, 1993.
- Pacific and Atlantic Ocean influences on multi-decadal drought frequency in the United States. Gregory McCabe, et al., 2004.
- Global pattern of trends in streamflow and water availability in a changing climate. P.C.D. Milly et al., 2005.
- Past peak water in the Southwest. Martin Hoerling, 2007.
- Stationarity is Dead: Whither Water Management? P.C.D. Milly et al., 2008.
- When will Lake Mead go dry? Tim Barnett and David Pierce, 2008.
- Response of Colorado River runoff to dust radiative forcing in snow. Thomas Painter, et al., 2010.
- Vulnerability of U.S. Water Supply to Shortage. Romano Foti, et al., 2012.
- The Holocene Dry Period: Multiproxy evidence for an extended drought between 2800 and 1850 cal yr BP across the central Great Basin, USA. Scott Mensing, 2013.