Irrigation Season Begins Amid Continued Concern About Drought
Apr 02, 2016
Snowpack is greater than last year in Central Oregon, but effects of 2015 drought lingerDrought conditions last year and recent measures to help the Oregon spotted frog are expected to affect water availability in Central Oregon for the upcoming irrigation season.
Irrigation districts began delivering water for irrigation to ranchers, farmers and other water rights holders Friday. The irrigation season typically runs into October. Some irrigation districts opened canals earlier this week for so-called “stock runs” to fill livestock ponds.
The snowpack level for the Deschutes/Crooked River Basin is considerably higher this year compared with last.
But water managers were unable to fill Wickiup Reservoir to capacity ahead of Friday after it was drawn down significantly last year. Water is released from the reservoir into the Deschutes River. Other reservoirs in Central Oregon have also failed to fill to capacity.
Irrigation districts and water regulators also agreed to release much more water than usual last month ahead of irrigation season. The increase was meant to provide higher water levels in the river for the spotted frog to breed. The frog has been listed as a threatened species under the Endangered Species Act.
The early increased releases out of Wickiup and drawing down the reservoir last year are expected to hinder the ability for it to be replenished by snowmelt during this irrigation season.
Mike Britton, general manager of the North Unit Irrigation District, which provides water in Jefferson County, said patrons of the district will have a reduced allotment this year, which also occurred during the 2015 irrigation season. The district receives water from Wickiup.
“We’re going to be impacted by that release and the fact that we weren’t able to fill Wickiup,” said Britton.
“This year is above average,” Jeremy Giffin, the Deschutes Basin watermaster for the Oregon Water Resources Department, said about snowpack. “But for this summer we’ll be drafting down Wickiup pretty low again.”
Two conservation groups, WaterWatch of Oregon and the Center for Biological Diversity, filed lawsuits against Central Oregon irrigation districts and the U.S. Bureau of Reclamation in December and January. The suits allege the districts and Bureau of Reclamation haven’t managed the Deschutes River adequately enough to protect the spotted frog.
The groups asked a federal judge in February to impose an injunction by Friday — April 1 — which would have altered water management by restricting how much could be released during the irrigation season. The judge denied the requested injunction.
“There would be a large part of the summer we wouldn’t be able to meet the demands of our patrons and customers,” said Britton, if the injunction had been granted.
The two sides are now awaiting a possible mediation process to resolve the legal dispute. The conservation groups have asked the judge to set dates for mediation to take place.
Separate from the lawsuits, irrigation districts and water managers voluntarily agreed to gradually release up to 600 cubic feet per second of water from Wickiup leading up to the irrigation season. One cubic foot per second is equal to nearly 450 gallons per minute. Normally around 22 cfs is released from the reservoir before the season starts, according to Giffin.
The voluntary agreement with the U.S. Fish and Wildlife Service was made to provide higher river levels for spotted frogs during the breeding season.
“We went ahead and ramped it up and high enough that we are already drafting down Wickiup, which is a little sooner than normal,” Giffin said Thursday.
The reservoir was about 88 percent full before Friday, according to Giffin. The reservoir can hold up to 200,000 acre-feet of water. One acre-foot can cover an acre of land in a foot deep of water.
Crane Prairie Reservoir, which is northwest of Wickiup, reached about 75 percent of its capacity over winter, leading up to irrigation season. The water stored there is used by the Central Oregon Irrigation District and other smaller districts.
Craig Horrell, manager of COID, said in an email he expects “across the board reductions” for the district’s customers. Water from Crane Prairie is also used to improve spotted frog habitat at the beginning and end of the irrigation season.
Giffin said by the second week of April demand for irrigation water where canals divert in Bend to district customers will start to outweigh the supply from the reservoirs.
“It’s on the way down for summer,” he said.
During the height of irrigation season, every couple of years, up to 1,800 cfs is released from Wickiup for a few days to keep up with demand.
Winter provided plenty of snow to Central Oregon, but the benefit of snowmelt and precipitation isn’t expected to be fully realized this year.
According to the Natural Resources Conservation Service in Portland, snowpack in the Deschutes/Crooked River Basin is 10 percent above normal, which is based on levels from 1981 to 2010. Last year, the snowpack dipped to 92 percent below normal.
Scott Oviatt, a snow survey supervisor with the service, said the amount of snow is a good thing, but not “unusually high by any means.”
“We’re not going to jump out of the drought immediately because of last year,” Oviatt said Thursday. “It’s a good start, and if we can maintain a slow melt this spring and not have it rapidly run off, then it will help us rebound from that.”
Last year, by the end of September, 25 Oregon counties were granted drought declarations by Gov. Kate Brown, according to the Water Resources Department.
“The drought is not over necessarily, but it will start to mitigate some of that,” Oviatt said about the increased snowpack during winter.
Water managers were able to fill Wickiup Reservoir ahead of irrigation season last year, but the lack of snow last winter caused its water level to drop quickly.
“Last year was a poor winter and the snowpack was way off,” said Britton. “Wickiup filled, but we weren’t able to provide full allotment to our patrons based on that.”
Giffin said that, prior to this year, Wickiup had been filled to capacity the past seven years before irrigation season began.
The Little Deschutes River running into the Deschutes River below Wickiup could help with keeping the reservoir at a higher level as the irrigation season progresses. Giffin said as temperatures rise he expects at least 800 cfs to flow from the smaller to larger river.
“When that happens we’ll be able to cut back the outflow from Wickiup and save some of the water in the reservoir,” he said.