Annual reduction of Wickiup outflow shakes up Deschutes ecosystem

Date:
October 20, 2021
Annual reduction of Wickiup outflow shakes up Deschutes ecosystem

From stranded fish to struggling surfers, the lowering of the Deschutes outflow to 105 cfs has big impacts

In Bend, autumn means piles of leaves, fleece jackets and sprinkler blowouts. Another sign of the changing season is the sudden drop of the water line in the Deschutes River after dam managers do their annual tightening of the spillway at Wickiup Reservoir.

The outflow from Wickiup Reservoir had fallen to just 125 cubic feet of water per second on Tuesday, down from 600 cfs a week ago. This adjustment is made every year to conserve water in Wickiup Reservoir for irrigation use the following year. The outflow will fall to around 105 cfs Wednesday and remain at that level until April.

Wickiup’s reduced outflow represents a perilous time for fish and wildlife as they cope with the sudden and artificial change in river level. The most visible impact occurs at Lava Island Falls where the drop cuts off water to a side channel of the Deschutes, leaving fish stranded along a 1.5 mile-long section of the river.

As they do every year, groups of volunteers descended on Lava Island Falls this week to mount a rescue effort with nets and buckets. Electroshocking equipment was used to help maneuver the fish into corners where they were captured.

Ben Briscoe, a field biologist who helped lead the rescue effort, said Tuesday the operation was going faster than expected and most of the fish would be pulled out by the end of the day. Work is expected to wrap up Wednesday.

The falling water level also impacts breeding areas for frogs and other species. Kate Fitzpatrick, executive director for the Deschutes River Conservancy, a nonprofit whose mission is to restore water to the Deschutes River, said the extreme shift in river height during fall and spring, erodes the banks of the Deschutes.

“Widening of the channel makes it harder for the river to access historic floodplains critical for river health and habitat for the Oregon spotted frog,” she said.

Fish in other parts of the river can also be harmed by the sudden drop, said Gail Snyder, founder of Coalition for the Deschutes, another nonprofit that advocates for improved river habitat.

“The annual fish kill has been happening for decades, but it doesn’t just happen at the Lava Island reach and it isn’t just fish that perish. It is a symptom of the overall poor condition of the river,” said Snyder.

The creation of Wickiup Dam and the widespread use of agriculture in the High Desert have contributed to the changing river habitat, said Snyder, who says there are new threats, too.

“Housing developments, urban runoff and recreation all affect the health of the river,” Snyder said. “We all use and rely on the river, and ultimately we all have a responsibility to care for it.”

In Bend, there are noticeable impacts in the Old Mill area and the Whitewater Park, where the dropping water level results in exposed rock and dicey conditions at the standing wave. Businesses that rely on the river are switching to their off-season mode.

“This time of year we don’t see a lot of rentals, but on nice days we will still send people out.We just won’t send them to certain sections of the river,” said Hannah Bolger, rental manager at Tumalo Creek Kayak & Canoe.

In the off-season, Bolger said, the shop stops renting bodyboards and surfboards but will still offer canoes, kayaks, and stand-up paddleboards for flat-water areas.

The standing wave will be smaller, said Bend Park & Recreation District wave shaper Ryan Richard, but still ridable.

“People will likely surf all winter with the discharge out of Wickiup at 100 cfs,” said Richard. “These people usually only surf on finless skimboard-style boards and often opt for more protective gear as the water is quite shallow over the gates.”

Further downstream, past the canal diversions, there is a different phenomenon. The water level in the Middle Deschutes actually rises because water is no longer diverted for irrigation. Over the past five days, the water in the Middle Deschutes has increased from around 75 cubic feet per second to 250 cfs.

Much of Jefferson County, home to the North Unit Irrigation District, is also keeping an eye on Wickiup Reservoir as its starts to fill with Deschutes River water. The amount of water in the reservoir doubled from a base level of 3,100 acre-feet on Oct. 11 to 6,200 acre-feet on Tuesday morning. An acre-foot of water is the amount of water to cover 1 acre of land in 1 foot of water.

The level will continue to climb at a steady pace right up to April when the irrigation season begins anew. Farmers are hoping that the reservoir can beat the level that it reached this past April when the irrigation year started with Wickiup at 115,000 acre-feet, or 58% of capacity.

But that will be a challenge as the reservoir is starting to fill from “ground zero” after it emptied in August, the second year in a row that it drained completely. Even lots of snowpack this winter doesn’t mean a return to normal as runoff first needs to replenish the aquifer before it can reach the reservoir.

Jefferson County farmer JoHanna Symons, who raises cattle near Madras, said piping projects meant to conserve more water could help farmers and aquatic life in the long run, but she acknowledges that filling the reservoir to capacity again has its challenges.

The Deschutes Basin Habitat Conservation Plan, which requires more water be left instream in winter to support frog habitat, is preventing a refill of the reservoir, she said.

“Even though piping projects are getting accomplished, we still have to release more water from Wickiup all winter long because of the HCP,” said Symons,”which makes it so Wickiup will probably never fill again.”

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