Oregon snowpack above average, for now
With a statewide snowpack that’s 134 percent of average, Oregon’s water outlook is healthy nearly two-thirds of the way into the snow accumulation season.
However, unless it increases from its current level, Oregon’s snowpack would still be below normal at the traditional peak in early April, said Julie Koeberle, a hydrologist with USDA’s Natural Resources Conservation Service
“The threat of rainfall in the mountains is there,” Koeberle said. “We’d rather not see it rain in the mountains. We’d rather it continue to build as snow.”
It’s been cold enough during recent storms for most precipitation to be deposited as snow, but there’s a potential for the snow level to rise to higher elevations, she said.
Rain wouldn’t likely have much deleterious effect on the snowpack in higher-elevation mountains, but it could melt snow at lower elevations, Koeberle said.
The Owyhee basin in southeast Oregon has the strongest snowpack in the state, at 160 percent of average, followed by the Willamette basin in Western Oregon, which is 150 percent of average.
The Grande Ronde, Powder, Burnt and Imnaha basin in Northeast Oregon has the weakest snowpack at a respectable 109 percent of average.
While current snowpack levels bode well for summer stream flows, it’s worth noting that Oregon was also in robust shape last winter, Koeberle said.
Record-high temperatures in April 2016, however, diminished snowpacks to the point where many streams were running below-normal in the summer, she said.
Due to low stream flows and strong irrigation demand, most of Oregon’s reservoirs were at below-average levels when the rainy season began last autumn, according to USDA NRCS.
Some reservoirs are now approaching average levels, but many have yet to catch up despite the improved water situation, the agency said in its February water outlook report.
The Hood, Malheur and Powder basins were faring the worst in early February, with reservoir levels below 35 percent of average. At 160 percent of average, the Grande Ronde basin had the strongest reservoir levels.