YAKIMA, Wash. — Mountain snowpack looks a whole lot better in Washington than it has at this time the last two years and Yakima Basin reservoir storage also is good.
Statewide snowpack was 120 percent of normal on Jan. 4 compared with 49 percent at this time last year and 44 percent two years ago.
But temperatures are about to rise and precipitation will slow down in keeping with an el nino weather pattern, said Scott Pattee, water supply specialist of the Washington Snow Survey Office of the USDA Natural Resources Conservation Service in Mount Vernon.
“If we can get maintenance storms and keep a buffer of snowpack we will be OK. If it totally shuts off and warms up, I’m not saying we will be in drought again but we would be water short in some locations,” Pattee said.
Snowpack constitutes two-third of the irrigation supply of 464,000 acres of farmland in the Kittitas and Yakima valleys. One third is stored in five lake reservoirs.
Odds are maintenance storms will come and there will be sufficient summer water, he said.
As of Jan. 4, the Spokane basin snowpack was the lowest in the state at 87 percent of normal. The upper Columbia (Okanogan and Methow rivers) was 129 percent. The central Columbia (Chelan, Entiat and Wenatchee) was 112, the upper Yakima was 113 and the lower Yakima, 120. The lower Columbia was 118, central Puget Sound (from Cascade crest to lowlands) 115 and the Olympics, 135.
All of those regions were well below 100 percent a year ago.
The first April to September streamflow forecasts will be around 100 percent of normal, Pattee said.
The 2015 drought illuminated the criticalness of snowpack, he said.
Rainfall and snowfall were down in prior state droughts, but 2015 saw ample mountain rain but little snow, he said.
“We were able to tie low streamflows directly to lack of snowfall. I don’t think any of us knew how critical it is, but the math is there now,” he said.
Meanwhile, the five reservoirs serving the Yakima Basin are 124 percent of average for this time of year. Keechelus, Kachess, Cle Elum, Bumping and Rimrock all total 55 percent of capacity as of Jan. 3, said Chris Lynch, hydrologist for the U.S. Bureau of Reclamation’s Yakima Project in Yakima.
“Things look good,” Lynch said. “We’re back into a more normal mode for now. You never know how the winds will shift, but we hope we will get some more winter and keep building snowpack.”