Owyhee Reservoir carryover portends solid 2024 supply
Published 2:13 pm Monday, October 9, 2023

- The Owyhee Reservoir near Adrian, Ore.
Even before snow season hits its stride, Owyhee Reservoir has nearly enough water to supply irrigators through next year.
Capacity in the reservoir near Adrian, Ore., is sufficient to supply irrigators for two seasons under normal circumstances. It was nearly half full as the 2023 season neared its last day, Oct. 13.
Volume to be stored between irrigation seasons is “very, very promising for next year,” said Bruce Corn, an Owyhee Irrigation District board member.
Nearly half full
Since the reservoir likely will be 48-49% full after the 2023 season, supply should be adequate for next year even if this winter’s runoff is low, he said.
“It makes it possible to plan for rotations next year, prepare ground properly and get off to a good start,” said Corn, who farms between Ontario and Nyssa.
Reservoir capacity is 715,000 acre-feet. After the 2023 irrigation season, volume of about 346,000 is expected, said Clancy Flynn, who manages the district. Postseason average volume is about 260,000 acre-feet— well above the 68,000 acre-feet a year ago and 58,000 acre-feet two years ago.
A wet winter and spring brought substantial snow and runoff that filled the reservoir and reduced early season demand.
In contrast, “when you have less than a full pool, you spend more time running around and making sure everything is really trim,” Flynn said.
Carryover ‘great’
Craig Froerer farms from Adrian to Ontario, across a 28-mile stretch that has a variety of topography and soils. His crops range from onions, sugar beets and mint to watermelon, asparagus and different types of corn.
“It’s really great for us,” he said of the good carryover in the reservoir. “It allows us to do what we really want to do.”
During low-water years, Froerer left some ground idle so available water could be used on high-value crops. But ground idled for a year can get too dry and suffer other consequences, he said.
With ample water, farmers can optimize rotations rather than planting based on water availability, said Bo Isham, a crop consultant in Homedale, Idaho.
“It just makes our lives so much easier because we can do what we’d like to do,” Froerer said.
Low-water years are “just not a win” despite moves to more efficient irrigation-delivery technology, he said. But with a healthy volume stored in Owyhee Reservoir after this season, “it is a very positive situation for us to be coming into.”
“With the good carryover we’ve got, even if we have good inflows, we should still be in pretty good shape,” said Frank Ausman, a district board member who raises feed crops and cattle about six miles south-southwest of Nyssa. He is not among district customers who also can access water from the Snake River.
Ausman’s custom hay work figures to stay steady as customers keep the crop instead of planting a lower-water alternative, he said.
An El Nino weather pattern is following three years of La Nina conditions. Historically, one is not better than the other for the Owyhee River drainage, Corn and Flynn said. The drainage includes parts of Nevada and Idaho.