‘We … let the river do the work’

A river restoration project is doing more than helping salmon thrive in a spot they once called home; it is potentially helping prevent future wildfires from wreaking havoc on the area. 

The McKenzie River Trust launched the first phase of a restoration on Oregon’s McKenzie River in 2021, and $1.7 million in funding came through in 2022, as NOAA Fisheries reported. In 2023, Chinook salmon spawned eggs in the new habitat, according to the agency.

Prior to that, years of development altered streams, which harmed the fish by affecting reproductive cycles and threatening the survival of juveniles.

The 150-acre restoration undertaking by the McKenzie River Trust at Finn Rock Reach reconnected a channel and expanded wet areas, slowing the flow of water and creating pools of protection. 

The salmon use gravel from the river bottom to create redds, or nests, for their eggs. But the narrow stream washed away the eggs and flushed young salmon downriver.

The 2020 Holiday Farm Fire had a severe impact on the watershed and its ecosystem, increasing erosion of the river’s banks. This pushed sediment downstream, which made it harder for fish to breathe — and lowered water quality. Eugene and other cities get their drinking water from the river.

The McKenzie River Trust announced the completion of the restoration work at Finn Rock Reach in 2023 — with the river more connected to the flood plain three years after the fire.

“We used a cut-and-fill operation to reconnect the river to the flood plain, dramatically increasing the wetted area where water can flow across the site,” McKenzie River Trust restoration projects manager John Trimble said, per NOAA Fisheries. “We then let the river do the work of rearranging the sediment into preferred flow paths.”

Another $7.6 million is set to finance a similar restoration of Quartz Creek, which feeds the McKenzie River. Chinook salmon and bull trout haven’t been seen there for decades, partly because an old bridge constricted the flow of water so much it gushed “like a fire hose,” according to the June report.

“Slowing down the water flow will keep juveniles from being flushed out and help keep spawning gravels in place,” NOAA marine habitat resource specialist Larissa Lee said. “Salmon need a certain size gravel to cover and protect their eggs.” 

Now, the flood plain will give the salmon and other wildlife a place to go when they’re seeking refuge from wildfires, and the salmon can head there if the water moves too fast as well. They can also feed there on nutrient-rich organic matter and insects. Felled trees and other woody debris create logjams that slow the water, spread it out, and filter it, forming a natural firebreak.

Join our free newsletter for good news and useful tips, and don’t miss this cool list of easy ways to help yourself while helping the planet.