Next up (down?): Gold Ray Dam

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Steve Mason, an Ashland fisheries biologist, stands by Gold Ray Dam. A sediment study to be released will bring removal or notching the dam closer.Jim Craven

July 26, 2008

By Mark Freeman

Mail Tribune

Jackson County officials will move one giant step toward notching or removing Gold Ray Dam this fall when a study begins on a century's worth of muck stuck behind the abandoned structure spanning the Rogue River near Gold Hill.

The long-awaited analysis of the sediment trapped behind the 104-year-old dam will help determine how best to proceed with creating 157 miles of free-flowing Rogue from Lost Creek Lake to the sea.

Already this summer, construction crews are in the process of removing the Gold Hill diversion dam downstream from Gold Ray Dam, and construction is well under way on a new pumping system to replace aged Savage Rapids Dam that spans the Rogue near the Jackson/Josephine county line.

With last week's initial blasts for notching Elk Creek Dam along an upper Rogue tributary, Gold Ray Dam has moved to first in line as the worst artificial fish barrier in the Rogue Basin and is considered one of the top removal priorities in Oregon.

"Right there in the Rogue it all seems to be happening at the same time," says Steve Mason, an Ashland fisheries biologist managing the project for Jackson County. "It's just boom, boom, boom. I really don't know why that is, but it helps."

Last week, the county accepted a $100,000 NOAA-Fisheries grant for the upcoming sediment study.

The money is part of a $400,000 pool of NOAA-Fisheries grants managed through Ecotrust, a Portland-based nonprofit organization.

Of that, $100,000 was earmarked for a single dam-removal project, "and this project won that," said Tamara Briggie, Ecotrust's forest-program assistant who worked on the grant.

Along with a $43,000 county match, largely in in-kind services, the money will pay HDR Engineering to drill core samples of the sediment to test for everything from mercury and pesticide levels to fine silts that could damage salmon spawning and rearing habitat or water in-takes if allowed to flow downstream, Mason said.

This study, which is required by the U.S. Army Corps of Engineers before any work can be done at the dam, should be completed by the end of 2008, Mason said. If the results lead the Corps to require further testing, the work could spill into next summer, Mason said.

The results could determine whether removal or notching could be done with a so-called "blow and go" scenario — removing the concrete and allowing the sediment to flow downstream, Mason said.

That scenario, which is how the work at Savage Rapids and the Gold Hill diversion were handled, likely would be favored over scooping out the muck and hauling it away, Mason said.

Shallow core samples dug and analyzed earlier this year by a Southern Oregon University crew found mainly sand and gravels and nothing alarming, Mason said. But that does not ensure Gold Ray could follow the downstream structures in how it gets removed, he said.

"Gold Ray is the biggest of the three dams coming out, and it has the most sediment," Mason said. "This should be very interesting."

Interest in doing something with the aged concrete dam spans the gamut of government agencies and private groups. The former hydroelectric dam was decommissioned 36 years ago.

The dam's fish ladder at times causes upstream migration blockages, and salmon and steelhead smolts heading downstream can plunge over the dam's 35-foot drop while finning toward the ocean.

The dam creates a thriving wetland for birds and other wildlife, but the impoundment warms Rogue flows and allows for predators to feed on infant salmon and steelhead.

The county, which took ownership of the dam and 29 surrounding acres in 1972 when it earmarked the area for a park, has civil liability for the structure.

"This is pretty exciting," said Lin Bernhardt, the county's natural resources manager. "Gold Ray Dam's been a liability for the county for years. This gives us an opportunity to move on that."

While notching or removing the dam is considered the county's preferred solution, it's not a foregone conclusion.

Sediment tests could show that the amount of material backed up by the dam and the potential presence of pesticides, mercury or other dangerous materials could point toward buttressing the aged concrete and improving fish ladders as better solutions.

No estimated cost or timetable for future work, including environmental studies, has been set, Bernhardt said.

Reach reporter Mark Freeman at 776-4470, or e-mail mfreeman@mailtribune.com.

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