Good news for salmon. Culvert project to bring full passage back to Tumwater creek

Out on Tumwater’s east side in between subdivisions lies a tiny oasis that can make you forget you’re in the city. Percival Creek runs four miles from Trosper Lake, down and around several neighborhoods to Capitol Lake and out into Puget Sound.

But salmon haven’t been able to reach their natural habitat in the headwaters of the creek for nearly 100 years due to a culvert that runs under Sapp Road. That’s about to change.

The city of Tumwater received grant funding to replace the culvert and open up the creek to coho, chum and trout for the first time since the road was originally constructed.

Project Manager Meridith Greer Jacobo said the city has received $2.3 million in grant funding so far to replace the culvert and reconstruct the roadway over it. The project will include adding sidewalks and bike lanes to the road, along with switching out the 5-foot-diameter culvert with a 19-foot box culvert.

“We’re looking forward to seeing what this means for salmon in the area,” Jacobo said. “We’ve heard stories — a lot of landowners who have lived here for a while have told me that they remember as kids seeing the salmon come up Percival Creek.”

Jacobo said it will be a big change for the area because it will involve shutting down the road in both directions for some time. She said the project has been on the books for years, and it’s actively been worked on since 2020. Construction will start in summer 2025.

“To be able to really open this up to not only benefit fish being able to get through but ultimately be a lot more pedestrian friendly, really improving the roadway is super important,” Jocobo said.

It’s unclear how long the culvert has been a passage barrier to fish, but the U.S. Geological Survey has maps of Tumwater dating as far back as 1937 that show a road intersecting the creek.

Restoration efforts on Percival Creek

Dan Smith, director of Water Resources and Sustainability, said good water quality and salmon habitat restoration have been missions of the city of Tumwater for decades. Since the late 1990s, he said crews have worked to restore parts of Percival Creek’s environment, starting with the construction of fish ladders downstream.

The plan to replace the culvert under Sapp Road has been on the city’s books since 1999, Smith said, well before the state Department of Transportation began looking at salmon passage barriers. That’s when the city bought 12 acres of old homestead property adjacent to the culvert for restoration efforts.

Since then, invasive species have been replaced with native trees that are now 30 feet tall.

When Jacobo joined the project, she, Smith and an expert from Wild Fish Conservancy came out to the culvert to perform Environmental DNA testing. That confirmed the presence of salmon up to where the culvert was in Percival Creek. It’s been identified as the only full barrier to fish in the waterway by the Department of Fish and Wildlife.

Jacobo said it’s considered a significant culvert to replace because about a third of Percival Creek is south of Sapp Road. Its headwaters are in Trosper Lake along with a lot of its wetland complex.

WDFW rated the habitat upstream of the culvert as excellent for salmon rearing.

“We’ve got a lot of macroinvertebrates for them to eat, we’ve got good water quality, some of which is spring fed,” Jacobo said. “The water is pretty darn cold, which is really good for fish, especially during the summer. So being able to open up such a significant portion, not only in terms of length, but also in habitat quality, is really, really exciting.”

A culvert on Somerset Hill Drive has been identified as a partial barrier and will be replaced after this one. Jacobo said fish are able to get through that culvert about a third of the time.

Jacobo said the creek is almost entirely in Tumwater, so it’s a unique opportunity for the city to do everything it can to ensure there’s healthy habitat for fish and those who live around the water.

A volunteer effort

Smith said the city is developing a detailed restoration plan for Percival Creek. What people can see to date has only been the early stages of restoration.

He said there are plans to build out a public trail through what’s being called Sapp Road Park, where people can view the creek and its wetlands, and the old structures that are remnants of a cattle farm. There already are trails through the park, but they’ve become overgrown. More restoration of the habitat will be done through volunteer work.

Smith said not only is the culvert replacement an environmental project, but a community project, too.

“We want to make the road more passable, we want multi-modal transportation where people can bike and walk along here, because if you can’t bike and walk to places like this, how can you appreciate places like this?” Smith said. “You have the reconnection of salmon to its habitat and the environmental benefits that come from that. You can’t have a healthy community without a healthy environment.”

Smith said it’s going to take some time to bring Percival Creek back to its former glory. He said he’s hoping to get community members out to the site who want to get their hands dirty and learn about maintaining the habitat.

More project details

The city of Tumwater originally received a grant from the Salmon Recovery Funding Board that helped with design permitting. Since then, Jacobo said the city has received another grant from the Salmon Recovery Funding Board and construction funding from PROTECT, a Washington state Department of Transportation program. It provides funding to help make sure surface transportation is more resilient to climate change and natural disasters.

Jacobo said the city was lucky enough to receive the first round of PROTECT funding in Washington and was one of only a handful of jurisdictions to do so. Funding from the second round will go toward the Somerset Hill culvert replacement project.

Jacobo said many of the city’s volunteer restoration efforts were accomplished through the Stream Team. a county-wide volunteer program that’s funded and run by the cities of Lacey, Olympia and Tumwater and Thurston County. Each city has its own team.

She said the Stream Team hosts free educational programs, hands-on science and learning activities, restoration events and more.

“It’s a really cool opportunity for the community to connect with these awesome natural places, alongside really knowledgeable people from the cities and county,” she said.

There also have been efforts to improve the water quality in the creek. Those efforts will be heightened during culvert replacement. Jacobo said the project will have stormwater treatment in the form of mechanical treatment in catch basins.

“That’s really important as we’re learning more about 6PPD-Q, which is tire dust particles,” Jacobo said. “As they break down, they are actually really toxic in water for coho salmon specifically. Ultimately, what we don’t want to do is remove a physical barrier to fish and still have a chemical barrier from a water quality perspective.”