The Deschutes River has trouble. Is this PGE water tower to blame?

Water temps are increasing. Insect populations are declining. Algae are blooming. A local group is pointing a finger at electric utility operations

Strategic withdrawal: Critics say PGE’s Selective Water Withdrawal Tower on the lower Deschutes River isn’t being properly operated. Photo: The Last 100 Miles/Peterson Hawley Productions

By Nathan Gilles. July 8, 2024. In summer 2010, retired fish biologist Steve Pribyl was on a three-day fishing trip with his wife on central Oregon’s Deschutes River.

While putting their boat in the water, his wife waded out alongside.

“I had noticed the river was kind of a funny yellow color. It didn’t look right. It wasn’t clear by any means,” remembers Pribyl. “Then as my wife wades out, she says, ‘What the hell is wrong with the river? It’s warm.’”

Pribyl previously worked for the Oregon Department of Fish and Wildlife, where he spent 23 of his 30 years at the agency studying and managing salmon and steelhead populations on the Deschutes River.

He says that around 2010 the quality of the water in the lower Deschutes—his longtime fishing haunt—changed for the worse.

In the years that followed, Pribyl learned that other anglers were also concerned by what they said was the river’s declining quality.

Among their complaints, they said the water was the wrong color and there was far more algae.

The local insects, they suspected, were less abundant, while snails had become more abundant.

Even the fish they pulled from the water had started to look unhealthy.

And they said the water was too warm.

All of this, they suspected, had to do with something happening upstream.

That something was a device that went into operation in December 2009 at the massive Pelton Round Butte Hydroelectric complex near Madras, Ore.

The hydroelectric complex, which consists of three dams and several reservoirs, sits along a 20-mile stretch of the Deschutes River Canyon. It provides power to an estimated 150,000 homes.

The device in question was and is the Selective Water Withdrawal Tower.

The 273-foot-tall tower was engineered to help out-migrating salmon find their way through the Lake Billy Chinook reservoir and out of the hydroelectric complex. It does this by changing water currents.

Still working it: Retired ODFW fish biologist Steve Pribyl. Photo: Eli Zatz

Widely hailed by the hydroelectric industry as an engineering success, even critics like Pribyl admit the tower has increased the number of anadromous fish leaving the hydroelectric complex.

But Pribyl and others say the tower has also increased the amount of warm, nutrient-rich water being sent downstream.

This, they say, has led to a series of unintended negative consequences to the ecology of the lower Deschutes River. Changes they have documented for over a decade.

Pribyl is a board member of the Deschutes River Alliance. Composed of anglers and scientists, DRA seeks to restore “colder, cleaner water in the lower Deschutes River” for the benefit of redband trout, salmon and steelhead and the people who fish them.

Formed in 2013, the DRA has been the leading critic of the Selective Water Withdrawal Tower.  

The group’s efforts opposing the tower and documenting what they say are its negative impacts are the subject of The Last 100 Miles: The Fight For the Lower Deschutes River, a new documentary that will debut at Cinema 21 in Portland on July 9. [Read Columbia Insight‘s review of The Last 100 Miles here.]

The documentary repeats a claim made by DRA members that the tower could be operated differently to lessen those impacts.

For the past four decades the Pelton Round Butte Hydroelectric Complex has been jointly owned and managed by Portland General Electric and the Confederated Tribes of the Warm Springs Reservation of Oregon.

Both PGE and the Warm Springs Tribes were sued by DRA in 2016 over alleged water quality violations downstream of the tower.

In 2018, a district court ruled in favor of PGE and the Tribes, finding, according to a tribal spokesperson, that the DRA “failed to establish that the project is operating in violation of its water quality certification from DEQ.”

The DRA’s appeal was later dismissed at the U.S. Court of Appeals for the Ninth Circuit on the grounds of tribal sovereign immunity. 

PGE disputes both the claim that the tower has negatively impacted the lower Deschutes as well as DRA’s claim that the tower should be operated differently.

Although PGE disputes DRA’s claims, the scientific know-how behind them can’t be so easily dismissed.

Warmer water, declining insects

Since joining DRA, Pribyl has put his background as a fish biologist to work for the organization. This includes writing a massive and extensively researched tome on the river published by DRA in February.

The report includes publicly available data from the US Geological Survey showing that river temperatures below the tower have increased sharply and are coming earlier in the year since the tower went into operation in 2009.

While not conclusive, the research is nonetheless compelling.

Along with tracking temperature, DRA actively monitors the Deschutes’ pH and dissolved oxygen levels. Both have changed since the tower began operating, according to DRA research.

The group has also been monitoring what it says are troubling declines in local insect populations that are tied to the tower.

“Some of the insect species that were quite common before [2009] have become less abundant than they used to be,” says DRA board member and retired scientist Rick Hafele.

The Selective Water Withdrawal Tower is part of the Round Butte Dam complex in the Deschutes River Canyon. Google Maps

Hafele formerly worked in the laboratory division at the Oregon Department of Environmental Quality, where he managed the agency’s statewide water-monitoring and bioassessment-monitoring programs.

He says he also helped develop the methods used to assess the health of aquatic life as it relates to water pollution, which involved working with the Environmental Protection Agency.

DEQ is responsible for enforcing the Clean Water Act in Oregon. DRA has based its water-monitoring program on DEQ protocols.

Antony Vorobyov, a spokesperson for DEQ, responded to Columbia Insight in an email: “DEQ and state and federal fish agencies are concerned about water temperatures and overall water quality on the Deschutes.” He added that the operation of Pelton Round Butte Hydroelectric complex project is “consistent” with the water quality standards monitored by DEQ.

In addition to working for DEQ, Hafele has taught fly-fishing for years and written eight books on the subject.

Like Pribyl, Hafele has spent his retirement fishing the Deschutes.

Local insect species that are now declining include the summer crane fly, the mahogany dun and the pale evening dun, according to Hafele.

“The warmer water has not been good for the river. The way they changed the temperature regime has really altered life cycles of the aquatic insects,” says Hafele.

Or is it just climate change?

The problem, says Hafele, is that the water being pulled by the tower and released into the Deschutes River is both warmer and richer in nutrients than the water that was released prior to the tower.

This, he says, has led to an increase in the local algal community, which he refers to as “nuisance algae.” He says as insects have declined and algae have increased, so have snails and worms.

Hafele says the overall ecology of the lower Deschutes is transitioning to a “more eutrophic, nutrient-rich” ecosystem due to the warm, nutrient-rich water being released upriver by the tower.

“What we’ve seen [on the lower Deschutes] is a shift from more sensitive pollution-intolerant, or pollution-sensitive, insects, to more pollution-tolerant invertebrates, primarily worms and snails, which have become much more prevalent,” says Hafele.

In addition to this, a disease called black spot appears to be affecting local fish populations. Snails, which feed on algae, are intermediate hosts for black spot.

New marks: Trout with black spot disease in Oregon’s lower Deschutes River. Photo: The Last 100 Miles/Peterson Hawley Productions

Megan Hill, hydro environmental manager at PGE, acknowledges that algae can be a problem on the Deschutes, but in general she says the river’s fish are doing well in the water downstream of the tower.

“I don’t think it’s an issue for the fish,” says Hill. “All the ODFW studies I’ve seen have shown that the actual fish population is doing well. They’re growing well, they’re eating well. We’re seeing similar densities to what we saw before the SWW [Selective Water Withdrawal Tower].”

Austin Smith, general manager of the Branch of Natural Resources of the Confederated Tribes of the Warm Springs Reservation of Oregon, agrees with Hill.

“I know timing-wise it doesn’t look great,” says Smith about the documented changes in temperatures since the tower went into operation. “But you can see the fact that there are fish returning due to the water withdrawal tower being in place.”

Smith says rather than being due to the tower, the warming on the lower Deschutes is more likely the result of climate change.

“There are a lot of different areas where there are bodies or water that over time with climate change have increased in temperature. Look at the Snake [River]. It’s also happening on the Columbia [River]; a lot of reservoirs, too. So, I wouldn’t tie [warming on the Deschutes] to the tower,” says Smith.

On the topic of black spot, he says although the disease can clearly be tied to nuisance algae, nuisance algae and black spot have been a problem in Deschutes River tributaries that flow into the river below the hydroelectric complex. This includes the Warm Springs River, which flows through the Warm Springs Reservation.

Aiding fish passage, collecting awards

The Selective Water Withdrawal Tower was created to meet a clear need.

In the early 2000s, the Pelton Round Butte Hydroelectric complex needed the Federal Energy Regulatory Commission (FERC) to issue it a new license to continue operating. This meant creating fish passage for both out-migrating juveniles and returning adults.

While returning adults could be trapped and trucked over the dam on their way to their spawning grounds, juvenile fish had difficulty finding their way to the ocean via the complex’s juvenile bypass system at Lake Billy Chinook.

At the bypass system, fish are collected and then hauled by tanker trucks past the complex to the open waters of the lower Deschutes.

The issue was the dams had altered the natural flow of the impounded sections of the river. Instead of flowing to the ocean, the cool current the outbound fish were following was flowing back up into the reservoir.

The current was sending the fish the wrong way.

To get its new operating license from FERC, PGE and the Warm Springs had to fix this problem.

To do so, the complex’s owners decided to try a revolutionary idea: attempt to alter the flow of the impounded water still more, this time intentionally and in a way that would send the young migrating fish to the juvenile bypass system.

Thus, the Selective Water Withdrawal Tower was born.

The tower works like a large straw.

In fact, “tower” is something of misnomer.

By design, the tower is almost entirely submerged in Lake Billy Chinook. By selectively sucking water from the reservoir and then releasing that water, the tower alters the reservoir’s currents, helping draw migrating juvenile salmon downstream to the bypass.

The withdrawal tower helped satisfy the requirement to ensure fish passage, and FERC issued PGE its new operating license.

The tower could also be used to manage temperatures downstream.

In 1998, the Oregon Department of Environmental Quality listed the lower Deschutes as impaired, meaning it frequently violated the Clean Water Act. This included temperature violations.

To receive its FERC license, the hydroelectric complex also needed to receive a 401 Certification from DEQ to come into compliance with the Clean Water Act.

The tower satisfied this need. The tower could be used to help restore a more natural “pre- project” temperature regime, according to documents filed with FERC.

Another plus: the tower could be used to help generate power.

Industry awards followed.

In 2011, the tower won an Edison Award from the Edison Electric Institute as well as an award from the American Council of Engineering Companies.

That same year, PGE and the Warm Springs won an Outstanding Stewards of America’s Waters award from the National Hydropower Association for the tower.

DRA members, however, claim the tower isn’t being operated as well as it could be.

Proposed changes

The Deschutes River Alliance’s beef has to do with where the tower pulls in water from Lake Billy Chinook.

DRA claims the tower is pulling too much warm water from the surface of the reservoir and not enough cool water from the bottom.

According to both PGE and DRA, the tower can pull only 60% of its water from the reservoir’s cool depths. The other 40% comes from the warmer surface.

The two different sources are then mixed to create a desirable temperature.

Saving grace: The Deschutes River was designated an Oregon Scenic Waterway in 1970 and a Federal Wild and Scenic River in 1988. Photo: BLM

This engineering constraint, says DRA, means the water released into the lower Deschutes is often too warm.

To overcome this constraint and solve what it says are quality issues downstream, DRA has proposed a simple solution: only pull surface water during the night when water temperatures are cooler.

PGE, however, doesn’t think this will work.

“The night blends that they’ve proposed and that we evaluated when we ran it through the models have not been shown to provide the benefits DRA thinks it will,” says Hill.

Smith declined to comment on DRA’s proposal, saying he hadn’t read it.

Smith, however, said that the Confederated Tribes of the Warm Springs Reservation understand the ecological trade-offs dams can create, as well as the negative impact that dams have had on native fish populations and the people who depend on them.

Smith added that the Warm Springs government has been working to address those impacts through its Branch of Natural Resources, and that its efforts are bearing fruit.

“We’re starting to see steelhead coming back,” says Smith. “We’re having record numbers of coho are coming in. Spring chinook are one of the most key iconic species of the Columbia, and they’re returning too. So, I just want to bring that up that we’re working for that.”

Hill says making any new operational changes to the tower will also require negotiating a new license with FERC, which would be a lengthy process.

Pribyl disagrees, saying the tower’s operation is most likely covered by the power provider’s ability to do “adaptive management,” that is, make small operational changes as needed.

“I think they may be able to sit down with FERC, say, ‘we’re going to exercise adaptive management here and here’s what we’re going to do,’” says Pribyl. “And I would bet a tall stack of dimes that FERC’s going to shrug their shoulders and go, ‘yeah, that sounds good.’”

Even if they’re wrong they might be right

What’s largely missing from the discussion of how to operate the tower is climate change.

Although it’s unclear what role climate change might currently be playing in warming the water of the lower Deschutes, climate change will most certainly warm the river in the decades ahead.

To help cool these warming waters, ideally, the tower should be operated differently.

This would mean, as DRA has recommended, avoiding pulling warm surface water until the sun has gone down and the water in Lake Billy Chinook has cooled.

But when I brought this up in my interview with Hill, she was largely dismissive of the notion of using the tower to adapt to climate change, saying “we can’t make cold water, so we have a limitation there based on the water coming in.”

Yet the idea that engineering solutions at reservoirs can be used to change water temperature and quality downstream isn’t exactly a stretch.

The tower was created in part to do just this.

What’s more, a growing body of scientific research into what are called “managed flows” has been exploring how to use reservoirs to help cool rivers and streams as climate change ratchets up.

This suggests that even if DRA is wrong and climate change, not the tower, is chiefly responsible for the changes observed on the lower Deschutes, the tower should still be operated differently.

If not now then in the future.

And this will mean taking a closer look at DRA’s claims and recommendations, both of which should not be so easily dismissed.