How scant is the snow in Oregon’s mountain ranges?
Forty-five percent of the state’s long-term monitoring sites, including automated stations and places hydrologists visit on foot, are at or near the lowest snowpack level on record.
In many cases, the records go back 25 years or more. About a dozen of the monitoring sites are snow free for the first time on record.
At this point in the year, snowpack recovery is unlikely, said Julie Koeberle, a hydrologist with the U.S. Natural Resources Conservation Service in Portland. As elsewhere throughout the Pacific Northwest and Northern California, the winter’s meager snowfall spells trouble for streamflows and irrigation supplies this summer. In many mountain ranges, including the north to south spine of the Cascades, the snowpack is 25 percent of normal or less.
At one snow site, at 5,470 feet elevation on Mount Bachelor, near Bend in Central Oregon, surveyors measured only 6 inches of snow, 10 percent of normal for the site and a record low in 60 years of record-keeping. The previous low at that point for March 1 was in 1977. In all, 32 Oregon monitoring sites had record low snowpacks and many more were near record lows, according to the NRCS.
Only an “immense” snowstorm would make a difference at this point, Koeberle said.
“Even rain would help the early need for irrigation, but snowpack is what sustains streamflows into the summertime,” she said. “Anything would help, but we’re so far in deficit for snowpack that it would take some kind of record-breaking miracle storm.”
As elsewhere in the West, Oregon’s precipitation since the Oct. 1 start of the water year has been much closer to normal, but it fell in the form of rain rather than snow. That helps fill reservoirs, which will ease concerns for irrigators who have access to stored water, but “anything in frozen form that we can use for water later” is more crucial, Koeberle said.
Local watermasters and the Oregon Water Resources Department would oversee any irrigation restrictions that might be necessary during the summer, she said.
In six Oregon river basins, the amount of water held in the snow – called the snow-water equivalent – ranges from 8 to 23 percent of the median registered from 1981 to 2010. The basin that includes the Grande Ronde, Powder, Burnt and Imnaha rivers, in the northeast corner of the state, is the only one to record even half of the historic snow-water equivalent.
The Owyhee Irrigation District in Southeast Oregon has been particularly hard hit by drought.
“Here we go once again,” the district said on its website, “we are unable to break this dry cycle that seems to keep plaguing us.”
The district is holding its annual water users meeting March 17 in Ontario to discuss the situation.
“Our snowpack was depleted early in February,” the district announcement said. “Spring runoff was a couple months earlier than normal and time is running short for fill from the watershed. Spring storms would be very welcome prior to the start of the water season.”
Philip Mote, director of the Oregon Climate Change Research Center at Oregon State University, described the snowpack situation as “atrocious.” The winter was the second warmest on record in the Pacific Northwest, behind 1933-34, Mote said in an OSU news release. Some parts of Eastern and Southern Oregon were up to eight degrees warmer than average this winter, OSU reported.
Source: www.capitalpress.com