A creek runs through it
The dam has been notched and water has started to find its way. Now all that’s needed is for the fish to return
Timeline of Elk Creek Dam
Elk Creek Dam was originally authorized as part of the Rogue Basin’s trio of dams meant to control winter floods and release stored water in the summer to enhance fish habitat. Lost Creek and Applegate are the other two. Here’s a brief history:
1986: Construction begins.
1987: Court injunction over fishery and water-quality concerns halts construction.
1988: Work on the dam ends Jan. 5.
1989: The U.S. Army Corps of Engineers proposes finishing the dam but with a hole in its base so Elk Creek could flow through it and fish could swim past it under most water conditions. The dam could still be used to curb flooding during high-water events.
1992: The Corps begins trapping and hauling fish around the dam.
1996: After continued resistance from environmental groups, the Corps decides not to pursue the environmental studies needed to get a court injunction lifted.
2006: The Corps plans to notch the dam before a permit to trap and haul threatened coho expires that year.
2007: The Corps has spent $113.9 million on the project as of Sept. 30. If the dam had been finished as planned in the late ’80s, the total bill would have come to $121 million.
2008: Blasting crews detonate their first load of dynamite under the $7.9-million contract to notch the dam on July 15. The final blast is detonated Aug. 17.
TRAIL — One unceremonious turn of a valve washed away a piece of Elk Creek’s history Friday as the first trickles of creek water tumbled down a newly built channel and through a giant notch in Elk Creek Dam.
The water is laying the foundation this weekend for a fall phenomenon not seen in this major upper Rogue River tributary since 1986, when the first bulldozers began scraping rock to make way for the dam, construction of which was later halted by lawsuits.
This fall the first wild coho salmon and steelhead will swim unimpeded past the U.S. Army Corps of Engineers dam again, ending 16 years of trapping adult fish at the dam’s base and trucking them to upstream spawning grounds.
“That’s really a great moment to see, the creek running back into its original channel,” said WaterWatch attorney and dam opponent Bob Hunter, who peered through smoky skies Friday at the damp channel from a viewing area off Elk Creek Road.
“It’ll be done in time for coho coming up this November,” he said. “That’s wonderful.”
Fish runs are at the crux of the $7.9 million notching of the dam, which the Corps concludes is the best and least expensive way to allow fish migration while the project remains mothballed.
Construction crews must wrap up work within the
creek late Monday, the end of the summer in-stream work period, and make way for spawning salmon to arrive.
Crews have finished building a new creek channel about 2,200 feet long, which stretches about 1,000 feet above and below the 200-foot-long notch created by the blasting of concrete from the abandoned dam.
The new streambed follows the original channel and consists of a series of soon-to-be riffles and pools aimed at giving migrating salmon their best shot at traversing a somewhat steep gradient on their way to upstream spawning grounds.
“It’s almost like a natural fish ladder they’ve constructed through that reach,” said Mike Evenson, a former Oregon Department of Fish and Wildlife biologist who ran the winter trap-and-haul program for the Corps the past five years.
“It’ll be interesting to see how things go here,” said Evenson, who visited the dam overlook Friday.
Since lawsuits forced construction workers to walk away from the project in 1988, the creek has flowed through a long concrete tunnel at the base of the dam. That tunnel proved too steep and flat for regular upstream passage of adult salmon and steelhead, including the Rogue Basin’s coho, which were listed in 1997 as a threatened species.
Five years earlier, while federal biologists mulled wild coho protection, seasonal crews built a metal weir across the creek below the dam to funnel upstream-migrating adult fish into a trap. Juveniles, however, were able to flush through the tunnel on their own.
That trap-and-haul effort ended last spring, opening the door for so-called “passive fish passage” this fall.
To create that passive passage, however, construction crews had to actively reload the channel.
This weekend’s efforts amount to recharging the channel’s soil and rocks, saturating the ground to trigger surface flow.
Until Friday, the creek flow, which was 6 cubic feet per second, had been piped around the demolition site. Then crews opened a valve that spilled half that flow into the new channel, effectively reconstituting the creek above the dam.
The remaining 3 cfs was piped around the dam to ensure that the creek below it did not dry up during the saturation process.
Through the weekend, flows were expected to creep downhill and reach 1.5 cfs at the fish weir at the downstream end of the project as early as tonight.
“If it all flows as we predict, we’ll push in the next 3 cfs for the full water-up Monday or Tuesday,” said George Miller, the Corps’ project manager.
Though notching the dam effectively ensures that threatened coho will swim freely past, steelhead likely will benefit the most, said Tom Satterthwaite, an ODFW fish scientist who worked on the project.
Satterthwaite’s studies on early trap-and-haul efforts concluded that the program worked “reasonably well” for coho, but not for steelhead, he said.
The Elk Creek Basin represents about 10 percent of the upper Rogue’s salmon and steelhead spawning habitat, Satterthwaite said. The numbers of returning adults and juveniles counted upstream of the dam were not judged to be largely impacted by trapping and hauling, Satterthwaite said.
“That definitely wasn’t the case for steelhead,” he said. “The steelhead production looked like it was one-fifth of what it should have been.”
The cause was never identified, he said. Suspected reasons included that steelhead that encountered the weir left to spawn elsewhere, or those trucked upstream dropped down and out of the system before spawning, Satterthwaite said.