This year's El Niño weather cycle is to blame for Idaho's poor snowpack and forecast low water supply, according to the National Resources Conservation Service.
Because current snowpacks are well below average, water users can expect low levels of runoff across the state.
"The weather pattern this year is typical during El Niño years, with good snow levels in the Southwest U.S. and below-normal levels in the Pacific Northwest," said Ron Abramovich, a water supply specialist for the service, in a press release.
According to the release, current streamflow forecasts in Idaho range from 45 to 80 percent of average.
As of Monday, the snow-water equivalent was 68 percent of average for the Big Wood basin, which includes the Wood River Valley as well as the Camas Creek drainage in the Fairfield area. Spring and summer streamflow for the basin is predicted to be 50 to 65 percent of average.
Around the rest of the state, the best snowpack is in the Owyhee basin, at 95 percent of average. The lowest are in the Coeur d'Alene, St. Joe and Palouse basins, which range from 50 to 55 percent of average.
According to the press release, the snow in the Upper Snake River basin in eastern Idaho and western Wyoming, currently 60 percent of average, is the fifth lowest in 50 years.
On the positive side, reservoir storage across the state is above average, thanks to holdover from last year.
Current storage is 92 percent of average in Magic Reservoir and 130 percent in the Mackay reservoirs. However, the release noted that more snow in the mountains or springtime rain will be needed to offset water shortages.
"[That] will help buffer impacts of below-normal streamflows," Abramovich said. "Water managers will monitor snow levels, inflows and spring weather closely when the melt season starts to ensure reservoirs fill as much as possible."
Jon Duval: jduval@mtexpress.com
