Western Creeks and Streams Will Continue to Dry Up, Study Says

A new study reports that drying climates in the American West will lead to a decrease in annual stream flow. In the Salt Lake City region, for example, researchers report the region could see as much as a 6.5 percent drop in the annual flow of streams that provide water to the city.

Writing in the journal Earth Interactions, a research team reports that by the middle of the century some of the streams that provide water to Salt Lake City will dry up several weeks earlier in the summer and fall.

"Many Western water suppliers are aware that climate change will have impacts, but they don't have detailed information that can help them plan for the future," said lead author Tim Bardsley, with NOAA's Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder. "Because our research team included hydrologists, climate scientists and water utility experts, we could dig into the issues that mattered most to the operators responsible for making sure clean water flows through taps and sprinklers without interruption."

The team relied on climate models and historical data to make their observations, as well as NOAA streamflow forecasting models.

"Many snow-dependent regions follow a consistent pattern in responding to warming, but it's important to drill down further to understand the sensitivity of watersheds that matter for individual water supply systems," said Andy Wood, of the National Center for Atmospheric Research.

The study focuses on which specific creeks and streams would be affected and how soon.

"We are using the findings of this sensitivity analysis to better understand the range of impacts we might experience under climate change scenarios," said co-author Laura Briefer, water resources manager at the Salt Lake City Department of Public Utilities. "This is the kind of tool we need to help us adapt to a changing climate, anticipate future changes and make sound water-resource decisions."

Salt Lake City Mayor Ralph Becker said: "Water emanating from our local Wasatch Mountains is the lifeblood of the Salt Lake Valley, and is vulnerable to the projected changes in climate. This study, along with other climate adaptation work Salt Lake City is doing, helps us plan to be a more resilient community in a time of climate change."