By Kate Prengaman
The Yakima Herald-Republic
ELLENSBURG — The settlers who founded Ellensburg in the 1870s were likely drawn by the plentiful water in creeks crisscrossing the valley, but as the city expanded, it grew right over those streams.
Look at a Google map of downtown Ellensburg and you’ll see Wilson Creek wind across Main Street. Walk the block, however, and there’s no sign of flowing water.
The creek, one of many in the valley that once supported salmon, now flows in culverts below the streets for about half a mile. Several blocks to the northwest, Mercer Creek runs below a motel parking lot. Across town, the creek briefly surfaces and then runs back underground, looking on a map like scattered stitches on a quilt.
Today, the sections of creeks trapped in concrete are one of the reasons that the wild salmon that used to swim here are extinct.
What exactly the creeks look like beneath the city remains a bit of a mystery. But Central Washington University scientists have discovered juvenile salmon can still survive in the city’s urban creeks.
Biology Professor Paul James and his former student, Kelsey Martin, hope their findings remind Ellensburg residents that the creeks exist and that with some restoration, salmon might be able to spawn in their midst.
Ellensburg isn’t alone. Cities around the country were built on top of small creeks and streams, but a growing number are now choosing to uncover them. Advocates say the practice, known as “daylighting,” can be cheaper than repairing aging culverts, create desirable waterfront parks or property, provide wildlife habitat, and improve water quality and flood control.
Seattle, Port Angeles, and Vancouver, British Columbia, are among the cities that have undertaken daylighting projects.
Culverts can be metal pipes or concrete tunnels of various shapes and sizes that contain and convey flowing water below roads, buildings and yards. On Central’s campus, removing an old dorm created the opportunity to daylight Wilson Creek for a block by replacing a culvert with a winding channel and planting native vegetation to make a small park.
Planners and engineers for the city of Ellensburg say that the city built over the creeks in lots of small projects over time and that records for what kind of culverts were used in long-ago construction are scarce. Records show that Wilson Creek was routed through a concrete culvert in 1914 below Water and Main streets.
Along Fifth Avenue, the sidewalk was built over section of creek in 1950, but the water still runs in a gravel bed below, not a concrete or metal culvert, according to city records.
The city does have a separate stormwater system, said senior planner Lance Bailey, but the system also discharges into creeks at points.
To study the viability of salmon in Ellensburg’s buried creeks, Martin and James released 6,000 coho into the creeks. They dumped the fish in two creeks, north of the city before the creeks go underground and south of the city, and then tracked them for a year until the surviving fish headed for the Pacific Ocean.
“This wasn’t some crazy idea I just had, fish biologists have been wondering for years about what is going on in these creeks under the city,” James said. “Once you get above the city limits, there’s some really nice stretches for spawning and rearing.”
Fish from the creeks were recorded at McNary Dam on the Columbia River, but far more Mercer Creek fish survived than Wilson Creek fish.
Out of 1,500 fish released above the buried sections in each creek, about 140 Mercer Creek fish made it to the Columbia, compared to just 75 Wilson Creek fish.
Yakama Nation coho biologist Todd Newsome said that James and Martin’s findings will help him plan future efforts to reintroduce coho to the region.
The Yakama Fisheries plans to develop a coho hatchery program in Ellensburg, which, like its spring chinook hatchery in Cle Elum, would be designed to specifically breed salmon that have adapted to survive the challenges of today’s Yakima Basin.
Figuring out in advance which creeks have potential habitat and which do not will help the eventual reintroduction succeed, Newsome said.
Each fish Martin released was raised at the Yakama Hatchery in Prosser and carried a tiny, injected tag. The tags, known as PIT tags, are programmed with identification codes that can be read by a scanning device. Martin spent the summer with that device, dodging spiderwebs to climb through 15 above-ground sections of the creeks around town to look for her fish, or their remains.
Living fish swim around, so Martin recorded the signal from their tags in different locations. But if a fish gets eaten, the rice-size tag will eventually pass through the predator and continue to give off a signal whereever it gets deposited. Tags from fish that die will settle on the creekbed with the bones.
On the university campus, a restored section of Wilson Creek flows below the shade of lush wetland plants, providing what James called great fish habitat. But no salmon swam up here to take advantage of it.
Newsome said that typically, juveniles wander both up and downstream, looking for a good place to feed and hide and grow for a year. But Martin found that none of the fish she released below the buried sections ventured upstream and survived.
At the end of the small campus park, the water flows into a grate and under Seventh Avenue, not to surface again for half a mile.
When the water emerges again, it spills into the sunlight from a dark concrete channel in a back alley behind a Main Street restaurant, looking less like a creek and more like runoff. Martin says she found a pile of PIT tags there, suggesting that the underground section is bad news for the young fish.
“There were like 66 tags right there,” Martin said. “What we don’t know is if there’s a bird here that’s eaten them or if they died under there.”
The parking lot seemed like unlikely habitat for a fish-eating bird, but if the fish died somewhere inside concrete culverts, it would make sense that their tags would be washed out to the pool below, Martin said. As far as why the fish could swim downstream but not up through the buried creek, she and James could only speculate.
James said he has requested a cost estimate from industrial scuba divers to survey the buried creeks, but he’s not sure if such a study would be feasible.
Newsome interpreted the data to suggest that further study should focus on Mercer Creek, where there appears to be better habitat.
“Just looking at the first year of data, Wilson Creek in the city is no good,” Newsome said. “Either it’s blocked by physical debris or there is a whole bunch of big brook trout in there. Usually dark means predators.”
About 5 percent of the fish released above that buried section survived swimming through it and made it to the Columbia River, Newsome said. That’s less than half the normal 10 to 15 percent survival he has seen in previous studies in lower Wilson Creek, outside of town, and what Martin and James recorded in Mercer Creek, which has several shorter buried sections.
Overwinter survival of juveniles is just one piece of the puzzle for successfully reintroducing coho, Newsome said. Spawning and rearing habitat are just as important, and they don’t always occur in the same streams, he added.
“Mercer Creek needs more investigation,” Newsome said. “It could be that part of it’s really good habitat and we could load it up with fish.”
That’s down the road, he adds. Releasing 6,000 fish might sound like a lot, but Newsome said from all those fish, the odds are that only a few adults will survive to return to spawn this fall.
Those that do make it will likely alter their course — there’s few gravel beds for spawning in the concrete channels of the urban creeks. Yet.
Looking down at creek pouring out from the culvert in the downtown alley, James spotted a small fish. Not a salmon, but a fish.
“Even as unnatural as it is, it’s still a functioning stream,” he said. “I think it would be so cool in a few years to see a coho salmon run in Ellensburg.”