Wickiup Reservoir at lowest level since early 1990s

September 6, 2018
Wickiup Reservoir at lowest level since early 1990s

Reservoir levels prompt concern from farmers, irrigation districts

Water levels at Central Oregon’s largest reservoir are lower than they’ve been in 27 years. And with no rain in the forecast, those water levels likely aren’t done dropping.

“I’ve never seen a season last this long without measurable rain,” said Gary Harris, a farmer living in Jefferson County.

As of Thursday, Wickiup Reservoir, which holds up to 200,000 acre-feet of water, was approximately 7 percent full, with just 14,446 acre-feet remaining in the reservoir. An acre-foot is the amount of water necessary to cover an acre of land with a foot of water.

In the last few days, the water levels in the reservoir dropped below those seen in recent famously dry years, such as 2015. According to records from the U.S. Bureau of Reclamation, the last time the reservoir dipped below 15,000 acre-feet was October 1991.

While farmers who depend on water from the reservoir are making plans now to conserve, Mickey Killingsworth, secretary treasurer of the Jefferson County Farm Bureau, said the most significant impacts of the shortage may not be felt until 2019.

“There’s a lot of concern,” Killingsworth said.

Kyle Gorman, region manager for the Oregon Water Resources Department in Bend, said the low levels were due to several factors: a low snowpack during the winter, a bone-dry summer, changes to water management due to a legal settlement for the Oregon Spotted Frog and a series of below-average water years that put farmers in the Deschutes Basin at a disadvantage going into irrigation season.

Gorman said the challenges began well before the year began. While the prior year brought a higher-than-normal snowpack, Gorman said it was the anomaly in a trend of dry winters. This reduced the amount of underground water feeding the basin, which can take several wet winters to replenish, according to Gorman.

Wickiup, as with other reservoirs on the western side of Central Oregon, entered last fall with more water than normal, but the good times didn’t last. Gregg Garnett, manager of the Bureau of Reclamation’s Bend field office, said the snow in the mountains melted more quickly than usual, resulting in less usable water for Oregon’s rivers and lakes.

“We didn’t have that continuous melt throughout the season,” Garnett said.

Those problems were exacerbated by a summer that has been dry even by Central Oregon standards. Marilyn Lohmann, hydrologist with the National Weather Service’s Pendleton office, said parts of Bend haven’t received any measurable rainfall since June, and storms have been few and far between since spring.

“It’s been extremely dry all the way since May,” Lohmann said.

Overall, Bend and other parts of Central Oregon have received less than half of the precipitation they would normally see since last October, Lohmann said.

Additionally, a settlement following a series of lawsuits around the Oregon Spotted Frog mandated that water levels on the Deschutes cannot drop below certain thresholds. For water managers, this means that once water gets released into the river from Wickiup, they need to keep water levels relatively consistent rather than allowing them to fluctuate, Garnett said.

Elsewhere in Central Oregon, the Ochoco Reservoir was 20 percent full Thursday, while Prineville Reservoir was 43 percent full. Both reservoirs were significantly below average for this stretch of the irrigation season.

Some irrigation districts — and the farmers they serve — have been hit harder than others by the water shortage. Shon Rae, deputy managing director for Central Oregon Irrigation District, said she was confident the irrigation district will be able to continue delivering water to patrons until the end of the irrigation season, typically around Oct. 10.

“It’s going to be a little tight,” she said.

Still, Rae said the district has a senior water right, and relies mostly on water from the Deschutes River, rather than Wickiup Reservoir. North Unit Irrigation District, a Madras-based irrigation district that serves about 950 patrons in Jefferson County, has a junior water right, forcing it to rely more on the reservoir.

Rae said COID’s conservation efforts have allowed it leave water in the river for the North Unit to use.

Still, Killingsworth said there has been talk within Jefferson County’s farming community that the irrigation district could stop delivering water later this month, adding that the decision will be discussed further at a board meeting next week.

In the meantime, the dry weather isn’t showing any signs of ending. Lohmann said the long-range forecast calls for drier-than-normal weather from September through October, with a possible El Niño weather pattern, which could bring more mild weather, expected this winter.

Killingsworth said most farmers in the area have cut back their water use, and are looking ahead to next year. Given Wickiup Reservoir’s current levels, Gorman said it’s extremely unlikely that it will fill completely this winter. If the upcoming winter is mild, it could contribute to dangerously low levels next year. And the water levels will continue to drop until the rain and snow comes.

“I don’t know how low it’s going to go,” Gorman said. “But it’s going to be very low.”

— Reporter: 541-617-7818, shamway@bendbulletin.com

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