This article was published on: 10/8/15 12:00 AM
Both at levels not seen in more than 20 years
By Dylan J. Darling / The Bulletin
Wickiup Reservoir south of Bend is lower now than it has been during fall in more than 20 years .
Low snowpack last winter and ongoing drought this summer combined to cause the low levels at Wickiup, a main source of water for farmland irrigation in Jefferson County.
As of Wednesday afternoon, the 200,000-acre-foot reservoir was 9 percent full, according to U.S. Bureau of Reclamation data. An acre-foot is enough water to submerge an acre of land a foot deep in water, or 325,851 gallons. Typically, this time of year Wickiup is about 32 percent full.
“There was just lower than natural flows (into Wickiup this year),” Kyle Gorman, region manager for the Oregon Water Resources Department in Bend, said Tuesday.
The last time the reservoir, which releases water into the Deschutes River upstream of Bend, was this low was in 1994.
That year also saw statewide drought.
This year, irrigators relied more on water drawn from Wickiup, Gorman said, because of the low flows in natural streams, such as the Little Deschutes River flowing at about half of normal.
While irrigation season is coming to a close and the rainy, snowy season is ahead, Gorman is not optimistic about the chances of Wickiup filling before the next growing season.
“I doubt it does,” he said. “I really doubt it.”
Groundwater typically helps fill the reservoir, but springs are not producing water as normal because they are not being recharged by snowpack.
Wickiup is not the only reservoir in Central Oregon with low water. As it was a low pool to begin with, little inflow this spring and summer have left 148,640-acre-foot Prineville Reservoir at 30 percent full.
The reservoir supplies water to the Ochoco Irrigation District, which delivers water to 20,000 acres in Crook County, as well as other water users downstream along the Crooked River. The last time the reservoir southwest of Prineville was this low was in 1992, Gorman said. That was another statewide drought year.
Amid drought, the Crooked River upstream of Prineville Reservoir ran dry this summer, hitting zero cubic feet per second at a state gauge at Post, Gorman said. This week, the gauge still shows just a trickle.
“It is still well below 1 cfs ,” he said Wednesday.
Gorman expects Prineville Reservoir to refill before next growing season, unlike Wickiup, due to differences in the Deschutes and Crooked river systems. Groundwater does not flow into Prineville Reservoir, which is fed by a more flashy river system based solely on rainfall and snowmelt.
Forecasters predict a strong El Niño this winter, meaning Central Oregon likely will see a warm winter like the last one, said Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University in Corvallis.
A weather phenomenon in the Pacific Ocean with ramifications for the entire West Coast, a strong El Niño would lead to a dry winter in Washington and a wet winter in California. As for precipitation in Oregon, Dello said it could be average, dry or wet — with more rain expected than snow because of the warm wintertime temperatures.
“Nothing is pointing to a big snow year,” she said.
— Reporter: 541-617-7812,