Underwater pipes could safely guide young salmon around damsAbout 50,000 tiny coho salmon of the Clatsop County CEDC Fisheries Project lent themselves to an experiment of a potentially ground-breaking fish passage system.
Gordon Burns used the fish to test a prototype of his dam bypass system, which he says offers a better, more efficient alternative to fish ladders, water spills, barging and other methods used to carry juvenile fish over or around dams on their downstream migrations.
On Thursday he watched as fisheries project staff at the Youngs Bay pen facility coaxed thousands of coho fingerlings from one net pen to another through Burns' specially designed water-driven "flow velocity enhancement system."
Water is pumped through a hose, creating a current that shoots fish through the 6-inch pipe.
LORI ASSA--The Daily AstorianBurns, a Montana resident and self-described amateur naturalist whose background is in pool construction and dam repair, came up with the idea after watching small fish swimming around an intake pipe at a gold-digging operation.
His idea is to set up an underwater pumping system above a dam that would create a flow of water to carry young fish away from the dam and into a man-made river channel carved around the structure.
His proposal, which he's dubbed "a dam site - better!" has caught the attention of federal agencies, including the Northwest Power Planning Council and U.S. Army Corps of Engineers, which are conducting reviews for possible funding from the Bonneville Power Administration.
Burns was put in touch with the Clatsop County fishery program through a former CEDC project employee now working for the power planning council. Fisheries Project Manager Tod Jones told Burns that the program's fish and net pens would provide a suitable setting for the experiment.
Water was pumped through the top arm of the device to simulate conditions if fish were caught through the flow velocity enhancement system. The CEDC Fisheries Project is part of the county's Community Development Department."I'm thankful for Tod and his people for making this possible," Burns said.
Thursday's experiment was intended to test the pipe arrangement - specifically, whether fish would be drawn into the pipe, and what the resulting harm would be. It's a crucial question for the power planning council's Independent Scientific Review Panel, which is studying Burns' system.
"The concept is not to suck the fish through, but create a current they will guide on," Burns said.
During the test, the fish were able to swim near the end of the six-inch-wide pipe without being drawn in. Only after fisheries workers began herding the four-inch fish toward the pipe did they start entering it, shooting out the other end in a silvery stream. Most appeared to make it through without harm.
"This has shown that the fish can swim away (from the pipe), and if they do go through, they don't suffer," Burns said.
The fish will be monitored for a month to see if they suffer excess mortality or any other ill effects from the piping process. In the spring, Burns will return and run the same test using bigger spring Chinook smolts, which will be closer to the size of migrating juvenile fish.
In actual operation on a river, the "velocity enhancement" pipes would be placed just upstream of a dam, near the bottom of the river below the normal depth of the migrating fish. The flow created by the pipes, Burns said, would direct fish into a bypass stream carved around the side of the dam.
The system has the potential for creating not only a form of passage past the dams less harmful to the fish, but one that would require far less water than is used in traditional dam spills, perhaps as little as 4 percent, Burns said. With that amount of water saved, a 10,000-foot-long bypass "river" could pay for itself in less than two years, he said.
The bypass streams themselves would be lined with shotcrete - concrete applied with a high-pressure hose - and designed to duplicate the flow and contours of a natural river, with varying grades and widths, pools, overhangs and other features. The stream would also serve as a better route for mature salmon returning upstream, he said.
Burns has proposed the system for use at the four hydroelectric dams on the Snake River in southeast Washington, which are the focus of debate over their possible removal to enhance native salmon runs.