A few miles below the PGE facility called Oak Grove Powerhouse, a stretch of the Clackamas River was just a trickle for more than 80 years. Now a person could wade in about hip deep.
“None of that water would be flowing here. There would be some water from tributaries and seeps and springs, but maybe only a tenth of what you see here,” U.S. Forest Service biologist Tom Horning explains.
In late 2011, following a relicensing process for its dams in the Clackamas River Basin, PGE started releasing water back into this stream.
“It looks like a river again. We’re hoping to see chinook salmon, which haven’t been present here. We’re hoping to see them start returning,” Horning said.
Three species of threatened wild salmon and steelhead spawn in the Clackamas River Basin. To get here from the ocean to spawn, they have to swim up the Columbia River, and through the city of Portland in the Willamette. Then they start the trek up the lower Clackamas, which is lined with urban development, agriculture and commercial timberland.
The Oregon Department of Environmental Quality has listed much of that lower stretch as impaired. DEQ says the temperature is higher than it should be to protect fish in the river.
But if the fish make it through that stretch — and around PGE’s dams — colder water and better habitat await them upstream. The upper Clackamas runs through a wild and scenic stretch in the Mt. Hood National Forest.
“The upper Clackamas and the lower Clackamas are radically different,” according to Patrick Barry, a biologist with the Oregon Department of Fish and Wildlife.
He says as the Forest Service has reduced the amount of logging on its land and left large buffers of older trees along the riverbanks, the habitat for fish has dramatically improved. The water’s colder and clearer. There are more places for fish to hide.
“Forest practices have changed in the last 50 years. And the Clackamas shakes out as one of the most pristine and rehabilitated habitats that we have really in Oregon,” Barry says.
So the state decided the upper Clackamas would be an ideal place to reintroduce a cold water predator: Bull trout.
It’s a major vote of confidence for the river and its salmon and steelhead populations, which bull trout actually eat.
“They’re kind of the top dog. They eat everything in sight and they eat themselves. They will eat a fish that is half it’s size and they’ll attempt to eat fish that are even bigger than half it’s size. We’ve come across fish that have gorged themselves and died because they couldn’t swallow their prey,” Barry says.
Over the past two years, Barry has brought more than 100 bull trout from the Metolius River to the upper Clackamas. Each one is tagged with a device that transmits a unique signal.
Barry can hear some of their signals while sitting in his office.
“You have to listen to a few cycles before you can figure out how many fish you’re listening to. It may be four,” Barry explains.
Barry also takes the radio receiver into the upper basin, to find out exactly where the bull trout are spending their time.
One place he’s finding them is that formerly dry stretch of river below PGE’s Oak Grove powerhouse.
“We just had one in there earlier this week. It’s pretty neat to see because we’ve had this trickle of cold water. And I thought ‘well, I don’t know if bull trout are ever going to use that’.”
Barry is now hoping to see bull trout spawning there. August is spawning season. So he will be checking to see how many of these newcomers have laid eggs to produce the river’s next generation of fish.
View Clackamas: A River In High Demand in a larger map