Snow and irrigation: Water content of snowpack in Upper Columbia Basin is at 116% of average

MOSES LAKE — The end of 2020 brought with it the Columbia Basin’s first serious snow of the season.

While snow on the ground in the Columbia Basin is nice to look at even as it makes movement and work more difficult, what really matters is how much snow is in the Cascades and the Canadian Rockies, according to Valerie Thaler, a meteorologist with the National Weather Service in Spokane.

“Our snowpack in Washington and Idaho is running pretty close to average for this time of year,” Thaler said, “currently running pretty average for snowpack and precipitation, and over the next couple of weeks we’re expecting a wetter and snowier pattern for the whole region.”

Thaler said the culprit for the expected snowier winter is La Nina, the name given to the process where counter-clockwise winds from the Pacific Ocean just off Antarctica drive warmer water from the coast of South America to the western Pacific, churning up cooler, deep ocean water to the surface.

It results in cooler, wetter weather in parts of the Pacific Northwest and western Canada, Thaler said.

Data available on the National Resource Conservation Service’s SNOTEL website tracks the region’s snowpacks. It shows the water content of the snowpack in the Upper Columbia Basin — which covers much of the state north of Grant and Lincoln counties well into British Columbia and feeds the Columbia River — is at 116% of average.

And while there’s no official measurement for the precipitation in Grant County, Thaler said the amount of water falling from the sky in both rain and snow in Wenatchee — where the NWS has a monitoring station — is at 2.9 inches, well above last year’s 1.1 inches and just slightly more than the normal 2.8 inches.

“For the Cascades, they’re running about like 90% to 100% of normal right now, pretty average,” she said. “It’s pretty good snowpack, hopefully breaking the drought that we’ve been seeing.”

The Columbia Basin is still mired in a drought, according to the United States Drought Monitor — a joint effort of the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration and the University of Nebraska National Drought Mitigation Center.

According to Andy McGuire, an irrigated cropping systems agronomist with Washington State University Extension in Moses Lake, the rain and snow will help dryland farmers in the region, but the year’s precipitation likely won’t end the drought.

“Rain will help dryland agriculture and will help with fall-planted crops in the irrigated region, like winter wheat,” McGuire said. “Rain also helps with early spring planting, before the irrigation system is full and functioning, but that depends more on late winter precipitation and not what we receive this time of year.”

Because much of the Basin’s agriculture is irrigated, McGuire said, the drought doesn’t really matter that much.

“Even though Central Washington is still in a severe to extreme drought, the irrigation system should be just fine,” he said.

The U.S. Bureau of Reclamation diverts about 3% to 4% of the Columbia River at Grand Coulee for irrigation purposes during a typical irrigation season lasting from mid-March through mid-October, according to Craig Simpson, secretary-manager of the East Columbia Basin Irrigation District, and Roger Sonnichsen, manager of the Quincy Columbia Basin Irrigation District.

The precipitation they worry about falls far away from the Columbia Basin.

“We annually keep an eye on changes in precipitation and runoff, as well as Reclamation’s reports on water supply, but have not yet had to make any adjustments to our operations and maintenance,” Simpson said. “We feel very fortunate to have one of the most reliable water supplies in the arid West.”

The irrigation districts spend much of the winter doing maintenance and repair work on pipelines, canals, head gates and pumping stations, Sonnichsen said.

“Our winter is lots of repairs and system improvements,” he said.

Charles H. Featherstone can be reached at cfeatherstone@columbiabasinherald.com.