TOKETEE — Spawning salmon and steelhead can now jump and swim through a man-made passage over the Soda Springs Dam to a portion of the North Umpqua River the fish haven’t traveled for 60 years.
Construction wrapped up this month on PacifiCorp’s $60 million fish ladder, and salmon already are using it. The ladder’s completion after nearly three years of construction also concludes a 17-year debate on whether to build a fish passage or tear out the dam 60 miles east of Roseburg
Monte Garrett, who led the project for PacifiCorp, said the fish passage balanced competing interests. The dam will continue to produce clean hydroelectricity for customers, while the ladder will enhance fish runs and protect wildlife, he said.
Removing the dam would have cost as much as the fish passage and would have raised electric rates because of the lost hydropower, Garrett said.
“Clearly, the studies showed that the best thing for the fish is to not have the dam here, but on balance the best thing for the fish and renewable energy is to have the dam in place but have a fish passage,” he said.
In 2003, federal regulators renewed PacifiCorp’s license to operate the Soda Springs Dam for the next 35 years, but the utility was required to build a fish passage.
PacifiCorp hired Douglas County contractors to build the ladder. At the peak of construction, about 100 workers were employed. The primary contractor, Todd Construction, started in Douglas County and now has headquarters in Portland. The other contractor, Weekly Bros. Inc., is based in Idleyld Park.
While impressed with the engineering feats that made the Soda Springs fish ladder possible, conservationists who attended a public tour of the dam this month expressed lingering skepticism.
“I think the best thing would be to take the dam out,” said Stan Vejtasa, conservation chairman for the Umpqua Valley Audubon Society. “If they knew how much (the fish ladder) would have cost, they wouldn’t have kept the dam.”
Since PacifiCorp doesn’t plan to remove the dam, Vejtasa said he attended the field trip to check out the fish ladder.
“I just want to make sure the fish survive their passage,” he said.
As construction drew to a close on the Soda Springs ladder, fish began safely traveling through it to new habitat, which includes three miles of Fish Creek and three miles of the North Umpqua River.
Workers finishing the project reported seeing large fish swimming upstream of the dam. Salmon have been spotted spawning above the dam near the confluence with Fish Creek.
“Coho salmon have already made it up the ladder,” said Weekly Bros. co-owner Todd Weekly. “As soon as we opened it up, we saw them a mile and half up (from the dam) the next day.”
PacifiCorp will conduct a yearlong evaluation of the ladder to make sure fish are making it through the passage’s 59 compartments, PacifiCorp aquatic scientist Rich Grost said.
The company will then monitor for 24 years the success of the ladder, which consists of a series of 10-foot wide concrete pools. Fish advance through the pools by swimming through holes 18 inches wide or leaping over a foot-high walls.
Chinook and coho salmon, steelhead, trout and Pacific lamprey are expected to use the 600-foot passage to traverse the dam, an obstacle fish encounter after swimming 180 miles from the Pacific Ocean to spawn.
Dave Harris, southwest hydropower coordinator for the Oregon Department of Fish and Wildlife, said it’s thrilling that fish can now get past the dam.
“Fish are going to be able to get into an area they haven’t been able to get to since the ’50s,” he said “It’s a pretty big deal to get those fish up there.”
By opening up more spawning habitat, the fish ladder should raise fish populations on the North Umpqua, Harris said.
Spawning fish are territorial and when crowded may dig up eggs of other fish, he said. So the more places they have to spawn the better, Harris said.
“You increase the number of juveniles that survive that go out to the ocean and come back for anglers,” he said. “There’s this overall upgraded survival of species above and below the dam.”
Grost said PacifiCorp estimates the fish ladder will increase adult populations on the river by between 200 and 600 chinook salmon and steelhead.
The Soda Springs Dam was opened in 1952 as part of the North Umpqua Hydroelectric Project, a network of generators in the Umpqua National Forest that creates enough power for 40,000 homes.
The dam regulates the natural flow of the river to generate electricity during times of peak demand, but it also prevented fish from swimming upstream to historic spawning grounds. Conservation groups pushed for the dam’s removal, arguing that it not only blocks spawning grounds, but also keeps gravel and woody debris from replenishing downstream spawning beds.
The Soda Springs fish ladder is part of a slew of PacifiCorp projects totaling $120 million aimed at mitigating harm to wildlife across the entire hydroelectric project, Garrett said.
The company has restored wetlands and added rocks and logs to the river to create better spawning habitat for salmon above the dam, he said.
“Fish are going to be coming over the dam, so we want to make sure the habitat is there for them,” Garrett said.
Spill gates on dams also let gravel and woody debris continue downstream to spawning beds.
These efforts helped the company win certification of the North Umpqua Hydroelectric Project as renewable energy, Garrett said. The certification came from the Low Impact Hydropower Institute, a nonprofit environmental organization based in Portland, Maine.
A state mandate that passed in 2007 requires utility companies to have 15 percent of their energy come from renewable sources by 2015 and 20 percent by 2020.
Hydroelectricity makes up about 8 percent of the energy Pacific Power produces, Garrett said. The majority of Pacific Power’s electricity comes from burning coal, but to meet state regulations to reduce carbon emissions the company plans to rely far more on renewable energy sources, such as wind and solar, he said.
Other PacifiCorp projects to decrease harm to wildlife include barriers to divert fish around hydroelectric generators and 39 bridges so animals can cross canals that channel water to the generators. Before the bridges were installed, between 15 and 20 deer and elk died drowned each year in the canals, Garrett said. Now fewer than five perish in the canals, he said.
Umpqua Valley Audubon Society President Diana Wales said the bridges don’t prevent smaller wildlife from drowning in the canals because they can’t walk as far as deer and elk to find a crossing. The canals should be fully covered, she said.
“We refer to it as the Great Wall of China because it’s impossible to get past,” Wales said.
Construction on the fish ladder began in May of 2010, and the weather, confines of the canyon and the geology of the North Umpqua River put the project a year behind schedule and increased costs many times above the original estimate
PacifiCorp estimated in the mid-1990s that a fish ladder would cost between
$8 million and $10 million.
Garrett described building the fish ladder as squeezing “tried and true concepts in a confined setting.”
“Originally, we had 17 different designs,” he said. “All of them were thrown away.”
After a peak of 100 workers last summer, about 20 Weekly Bros. employees helped put the finishing touches on the ladder this month, Weekly said.
“It was the largest project in the history of our company and the toughest,” he said.
The project required diverting the North Umpqua into a pipe away from the construction site, drying up about 400 feet of riverbed, he said. The remote location of the dam also meant the contractor had to build roads to bring in heavy construction equipment, Weekly said.
Winters were especially challenging, with floods slowing progress, he said.
“It’s an accomplishment, and I’m very glad to be done with it,” Weekly said. “I’m glad to not to have to spend another winter in that narrow canyon.”
Besides the $60 million fish ladder, PacifiCorp estimates that over the 35-year license period, it will spend another $1.2 million on maintenance and other capital improvements on the North Umpqua project.
Still, PacifiCorp estimates the fish passage will increase rates by less than 1 percent, utility spokesman Monte Mendenhall said.
Wales, who pushed for the dam’s removal, said she’s disappointed it remained, but hopeful the fish ladder will serve its purpose.
“It ended up being a compromise,” she said. “At this point, it’s like, I just hope it works because it’s what we have for another 35 years.”
• You can reach reporter Inka Bajandas at 541-957-4202 or email at firstname.lastname@example.org.