Utah's climate a challenges to water supplies

Global warming may be a worldwide phenomena, but the warming trend experienced in the West is already on Utah's doorstep, posing immediate challenges for those who predict annual water resources and those who have to live with the realities.

Some grim news as well as ways to meet the dilemma were presented Tuesday at a first-of-its-kind conference bringing together scientists, hydrologists, water supply managers and user associations.

The daylong Salt Lake City Library symposium on climate change and water supplies in Utah was an attempt to view climate change and its impact through the nonbiased view of science, said senior hydrologist Brian McInerney with the National Weather Service in Salt Lake City.

"This is the first time anybody from the National Weather Service has done anything like this," he said, adding the symposium grew out of repeated requests by water managers to chart temperature and its impact on water resources.

A presentation by Robert Gillies, a Utah State University professor and state climatologist, pointed to a warming trend in the western United States that is increasing faster than the global average. For the past 50 years the West has had:

Longer frost-free growing seasons

Earlier and warmer springs

Earlier spring snowmelt and runoff

Greater fraction of spring precipitation falling as rain instead of snow

Those impacts play out in a variety of ways, from droughts that lead to longer and more intense fire seasons to moisture-deprived trees susceptible to insect infestation. While such warming decreases snowpack totals and poses challenges to the state's water supplies, experts warned that the climate shifts that Utah may experience don't necessarily mean less precipitation — it just comes in a different form and at a different time.

More springtime rain, less overall snow and an earlier runoff is frightening proposition to water managers.

"Our existing infrastructure under the more-rain-less-snow scenario is insufficient," said Tage Flint, general manager of the Weber Basin Water Conservancy District.

Keith Denos, Provo River Waters Users Association general manager, likened Utah's snowpack totals as a "reservoir" that sits on top of the mountains.

"We're used to it being full the first week in June. If it becomes full in April that is a concern," he said.

Managing those shifts of when Utah's snowpack melts is compounded by population growth, which puts more strain on water resources.

"Will (water supply) be a growth limiter when it comes to planning?" Flint said. "If the inherent amount of water becomes less over time, we will enter that debate a lot more quickly than we thought. Should supplies to agricultural users be cut before municipal users? Do we short our lawns for farms? Do we not take showers so our crops can grow? There are all sorts of debates coming from this."

E-MAIL: amyjoi@desnews.com