Two Of Oregon's Worst Dams For Fish Are Coming Down

Aug 10, 2015

It can be tough for salmon and steelhead returning to spawn in Northwest rivers and streams. High water temperatures, parasites, and predators all pose natural threats.

But the fish also encounter man-made obstacles – like dams - that make getting to the best spawning habitat difficult.

Southern Oregon is getting a reputation as a place where efforts to improve fish passage are succeeding. Two significant dams in the Rogue watershed are coming down this summer.

Demolition crews knock out first notch in Wimer Dam on Evans Creek, a tributary of the Rogue River.
Credit River Design Group

Evans Creek is barely a trickle. A dry summer means the important salmon and steelhead creek disappears below the gravel bed in places, leaving isolated pools.

Normally, this wouldn’t be considered a good thing. But right now, Brian Barr will take it.

Brian Barr: “Believe it or not, we got lucky from the perspective of not having a lot of water. We’re in the middle of the second year of a really bad drought here in Southern Oregon, and it just happens to be the year that we're constructing.”

By “constructing,” he actually means demolishing the Wimer and Fielder Dams, near Grants Pass. Barr is overseeing the dam removal project for GEOS Institute.

Brian Barr: “Water is an incredibly powerful force.”

He says managing it is perhaps the most challenging aspect of any dam removal project.

The Wimer Dam site is about 9 miles upstream of where Evans Creek hits the Rogue River. Crews have removed about half the 11-foot tall concrete structure. But instead of the drama of explosives, the chosen demo method is jackhammer.

Threatened coho salmon jump up against the Wimer Dam.
Credit ODFW

Brian Barr: “Most dams don’t go in a puff of smoke with a giant stream of chocolate milk coming out the downstream side. Usually you very carefully route water around or through the structure and then you slowly and methodically, like with a dull butter knife, take the concrete down and gently on the side of the bank and into a dump truck.”

The work is slow, but the result will make a huge difference for fish.

Both the Wimer and Fielder Dams have fish ladders, but they don’t work particularly well. In fact, when Oregon Department of Fish and Wildlife Biologist Jay Doino went to clear out native fish like baby coho before demolition began, he didn’t find any.

Jay Doino: “What we found was were all non-native species, we found red-side shiners, bull frog tadpoles, actually only one of those, and a whole lot of ringed crayfish.”

Bob Hunter is a WaterWatch of Oregon Boardmember. He says removing the dams will open up Evans Creek for steelhead, fall Chinook, and federally protected Coho salmon.

Bob Hunter: “By doing the two projects together, we get the sort of synergistic benefits of removing two of the remaining barriers to access this habitat for fish. We’re talking about 70 miles of good salmon and steelhead habitat.”

ODFW lists Wimer and Fielder as two of the 10 worst barriers to fish passage – out of more than 40,000 manmade obstacles on Oregon waterways.

Back at the Wimer dam site, demolition crews are basically on schedule. They’re required to have both dams removed by mid-September.

Brian Barr: “Nothing is left behind. We will take every piece of concrete that we can find out of the river.”

But after a 20-year career working on dam removal projects, Barr says he doesn’t expect personal satisfaction to come immediately.

Brian Barr: “Honestly, where I kind of tear up, or well up, or get really excited is when I go back in about a year. It's when I have to go back and take repeat photos and I'll look at the picture I have. Okay I was standing on this rock and that tree was in the middle of the frame and there's a big piece of concrete. And then I set it down and I frame up that same image, and it's a creek. That's where I feel it. ”

By that time, with a little luck and heavy rains this winter, nearly 100 years of sediment buildup will wash away. Then the fish will move in, increasing Rogue River salmon runs for centuries to come.

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