Water managers and scientists tracking climate change said Friday that they hope a new $2 million study will produce strategies for dealing with Southern Nevada’s primary water source on the Colorado River if supply dwindles and demand increases during the next 50 years.
The two-year study, which is under way, will look at risks to the supply if temperatures continue to increase as they have in the past decade, said Terry Fulp, the Bureau of Reclamation’s deputy regional director for the Lower Colorado Region. The study is funded by the bureau and the seven Colorado River Basin states.
“There’s a lot of uncertainty. We know very little about next year’s runoff,” Fulp said during a symposium in Boulder City sponsored by the Desert Research Institute, the research arm of the University of Nevada system.
He said the study will consider the predictability of precipitation and snowfall on the western slope of the Rocky Mountains, which feeds the river and lakes Mead and Powell.
Scientists are looking back in time, particularly during the past 40 years, to develop climate change models around the globe that focus on temperature and precipitation in light of changes in ocean currents and greenhouse gas emissions that lead to increased surface temperatures.
“Most people believe temperatures will continue to rise over the next 50 years,” Fulp said.
The models, however, carry a great degree of uncertainty with estimates on how much the water supply will decrease ranging from 5 percent and 40 percent.
“We see it in the 10 percent range of possible decline. That means we’ve got to ratchet down demand and increase supply,” he said.
Drought conditions during the past 10 years in the Colorado River Basin have kept runoff at 68 percent of normal, causing the level of Lake Mead to drop to its lowest point since the mid-1960s when Lake Powell was filled upstream of Mead.
Kay Brothers, deputy general manager of the Southern Nevada Water Authority, said her agency is exploring ways to keep up with the demand for water. These include a possible pipeline to pump groundwater from eastern Nevada to the Las Vegas Valley and a program to desalinate ocean water in California for use there in exchange for taking more water from the Colorado River system for use in Southern Nevada.
She said the authority continues to benefit from water conservation by the local community and cloud seeding efforts to increase precipitation in the basin. In recent years, customers have been more efficient in watering lawns with more emphasis on desert landscaping.
“As we go forward in the future, we’ve got to change how we use water and power,” Brothers said.
Nevertheless, she said, “It doesn’t matter how much conservation you have. If you have an extended drought, you’re going to have to have additional water sources.”
Tom Piechota, director of Sustainability and Multidisciplinary Research at UNLV, said a future water crisis needs to be attacked on all fronts.
“There’s no one silver bullet,” he said. “It’s going to be a combination of solutions to get us through the next 25 years.”
Doug Boyle, associate research professor at the Desert Research Institute in Reno and director of the Nevada Water Resources Research Institute, said it will take time for climate models to improve. In the meantime, scientists must grapple with big uncertainties as they attempt to make observations for decision-makers.
Said Fulp: “What we really need is Mother Nature to turn around and give us some breathing room.”
Contact reporter Keith Rogers at email@example.com or 702-383-0308.