SPRINGVILLE — Water sources in Utah this year aren't producing as much as in past years, but it has nothing to do with global warming, a Natural Resources Conservation Service researcher said.
In short, Utah water supplies are above average in the southern part of the state, but they diminish as one travels north, Randy Julander said Thursday at the 2010 Irrigation Conference and Expo at Sprinkler World.
The Virgin River Basin has collected 162 percent of the average snowpack this winter, Julander said. However, with the exception of southeastern Utah, the rest of the state is dry by comparison, with much of the state falling below average.
The Utah Lake, Jordan River and Tooele Valley areas are about 74 percent of normal based on expectations by April 1, he said.
Spring runoff likely will be diminished because soil saturation throughout the state is below 40 percent. However, the trend in reservoir water storage is better this year than the previous year, Julander said.
The floods in southern Utah that washed homes downstream and caused havoc in the St. George area five years ago happened because twin 10-inch storms saturated the earth leading to tremendous runoff. That likely won't happen this year, he said, although the Virgin River Valley is flush with water.
"We could have a wet spring," Julander said. "It's possible, but the probability is we're headed down the tank."
Utah is drier now than it has been in the past five years, he said. Some areas are so low in snowfall this year that if they had the most snow ever in coming weeks, they still wouldn't achieve an average snowpack by April.
Spring runoff has little to do by itself as a global warming indicator, Julander said. The U.S. Department of Agriculture officially recognizes global warming, but in Utah it hasn't manifested, he said.
Among the factors for determining if the Earth is getting warmer is climate change, reduced snowpack and early melting. However, other factors also could cause those effects, and they're not related to global warming, Julander said.
Changes in vegetation, including trees and forest canopy growth, results in reduced snowpack, he said. Switching sensors from stainless steel to a synthetic material also has resulted in false readings favorable to global warming.
A snow researcher, Julander said he has found no statistical difference in snow melting earlier now than in past years.
"There is no pattern of early melt," he said, looking back to 1939.
Research dating from 1950, however, does show a pattern, though Julander says it isn't a long enough time period to get accurate data.
He also has found no difference in stream flow except for cyclical trends over the past 80 years.