The U.S. Army Corps of Engineers wants to right a fish-induced wrong. And doing so means costly and deadline-sensitive work at dams in Oregon’s Willamette River basin.
As salmon and other fish face declines as they struggle to return—past dams up to 400 feet tall—to original spawning grounds, the corps hopes to remedy some of those issues by constructing new fish-collecting facilities at four dams, according to an article in Oregon’s DJC.
The Willamette River-area dams, also used as flooding barriers in some locations, pose massive hurdles for spawning fish working to get upstream. A traditional fish ladder simply won’t do because of the size of the dams and fish are often put through a series of gates, slides and pipes before getting pumped into a truck for delivery to their ground.
All this non-natural movement throws off the fish and the handling of them can certainly injure them. Plus, fish prove sensitive to water levels and will sometimes jump when engineers don’t want them to, potentially injuring or killing the fish. Reports claim that up to 90 percent of fish don’t make it back to spawn, with much of that blame put on the dams’ crude systems.
To help the process, crews will upgrade the facilities, but do so in tight timelines, careful not to harm the fish they hope to protect. Those small windows mean that construction bids have heavy penalties for work not completed on time.
Last year the four-dam project kicked off with a $24 million project near Detroit Dam, standing at 463 feet tall, on the North Santiam River in the Cascade mountain range. This fall expect a project at Foster Dam and Reservoir Adult Fish Facility in Lane County. Two more projects, both on the middle fork of the river, are being designed. In all, according to the local article, $42 million has been allocated to these fish-helping projects in fiscal year 2012.
The biggest changes expected is in how fish are sorted and moved. The current process is highly intrusive, especially when it comes time to sort breeds, and the new process hopes to ensure a smooth transition and take the human element as far from the procedure as possible. As officials throughout the Pacific Northwest discuss—and participate in—the ripping out of aged dams, upgrading fish-sorting facilities will be just one model discussed as a way to return wild fish to the area’s rivers and streams.
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