Fish runs slowly returning
More than a decade after Portland General Electric and the Confederated Tribes of Warm Springs announced a joint project at Round Butte Dam to restore fish runs above the dam, officials are encouraged by their progress.
"In total, since adult returns began in 2012, we've transported 1,467 returning salmon and steelhead and released them into Lake Billy Chinook," said Steve Corson, PGE spokesman. As a result, they have seen spawning activity on all three of the upper tributaries — the Deschutes, Crooked and Metolius rivers.
"We had 17 fish transported upstream in the 2017-18 summer steelhead run, last fall and this past winter," said Corson, noting that two spring Chinook had already returned this year, "but it's still early. The sockeye won't start coming back 'til mid-July."
Below the Round Butte Dam, progress has also been made. "Heading downstream, we've transported a total of just under 1.3 million juvenile salmon and steelhead through the selective water withdrawal collection facility and into the lower river since the project began in 2010," said Corson.
"The numbers vary considerably from year to year due to conditions beyond our control, like snowpack and runoff," he continued. "In 2017, we had a record 450,000 fish pass downstream, boosted by high water. This year, with much lower flows, we've transported about 71,000 fish downstream."
"What it illustrates for our project is there are things we can control, but Mother Nature is still the controlling partner here — whether it's precipitation and water levels on the Deschutes or ocean conditions," he said.
Restoration of fish passage was the primary goal of the construction of the $108 million selective water withdrawal tower, which was started in late 2007, and completed two years later, with the system going live on Dec. 2, 2009.
The 18-story underwater structure blends the cooler water from the bottom of Lake Billy Chinook with the surface water, to improve water quality and attract migrating salmon for collection and transport around the project.
Fish are drawn into two V-shaped intakes near the reservoir's surface. Screens on the sides of the intakes drain the water, but keep fish moving through the system to the fish collection facility, where they are sorted by size and species.
"We're in our eighth year of operation, but in terms of fish life cycles, we're only about three life cycles in," said Corson.
There are four main species of fish in the rivers targeted by the project: sockeye salmon, spring Chinook salmon, summer steelhead and fall Chinook. "Of those, the only one that wasn't cut off by dams was the fall Chinook.," said Corson. "They spawn in the Middle Deschutes, below our project, and don't pass upstream above our project."
The sockeye, spring Chinook and steelhead are all anadromous — hatching in fresh water, migrating to the ocean, and then returning to fresh water to spawn.
"They'll spend a couple years rearing as juveniles — from fry to smolts in upstream tributaries — and a couple years in the ocean. It's a long-term process," said Corson.
Not everyone has been satisfied with the changes brought about by the selective water withdrawal tower and the reintroduction progress.
In 2016, the Deschutes River Alliance filed a lawsuit against PGE in the U.S. District Court in Portland, alleging violation of the Clean Water Act below the Pelton-Round Butte Hydroproject.
Both sides have filed motions for "summary judgment," asking District Judge Michael Simon to decide the case based on its merits, without a full trial. Simon is scheduled to hear oral arguments in the case on July 17, in Portland.
"We have a difference of opinion here about what's going on in the river, and what some of the causes may be," said Corson, pointing out that the selective water withdrawal tower was intended to change the temperatures in the lower rivers.
"The temperature patterns in the river, from when the dams were built in the late 1950s and early 1960s, were unnaturally cold in the early spring and summer, and then unnaturally warm in the late summer and early fall," he explained.
"So, in addition to fish passage, the selective water withdrawal system lets us mix cooler water from the bottom of the reservoir with warmer water from the surface of the reservoir to mimic the natural temperatures," said Corson. "We use a formula that looks at the temperature of the water that's entering the reservoir from the Deschutes, the Metolius and the Crooked rivers and then factors in ambient temperatures to calculate what the temperature would have been just below the project if the dams weren't there; that's our target, to release water that's about that temperature."
"The effect of that is to correct that problem that the dams have created, so temperatures are a little warmer in the early spring and summer than they were," he said.
"Probably the most direct benefit of the temperature is that it helps the fall Chinook; by warming things up, it changes the timing of the insect hatches — makes them a little earlier — and changes the feeding habits for the juvenile Chinook, letting them grow a little," he said. "With this change, these fish tend to be a bit bigger when they migrate out to the ocean, which improves their survival. Also, they get down to the Columbia a little bit sooner, when it's not as warm during the summer season."
In order to address the concerns of anglers and other stakeholders, PGE has been conducting an ongoing water quality study to determine the impact the program has had on water quality, both above and below the project.
"The selective water withdrawal is not the only factor that's changed on the river in the past eight years," said Corson. "We've had some of the hottest weather on record; we've had high water years and low water years; and then of course, Central Oregon is growing rapidly, and that has an impact on water quality, as well."
From 2015-17, PGE gathered water quality data at numerous sites, both above and below the project. "The study is being conducted by an independent consultant; we're sending it out for another independent review by a different expert before we release it," he said. "We hope to have a report available this fall. Our goal is to have good information and be transparent about sharing it with our stakeholders."
PGE is optimistic that the project is moving the partners closer to their objective.
"The goal of our project was to restore fish passage, so we could have wild fish, not just hatchery fish, above the project and throughout the Deschutes Basin," said Corson. "We're really in the early stages of the reintroduction program. We're encouraged by the progress we've made to date, but we're certainly not declaring victory."