A new form of fish passage is bringing hope to the Yakama Nation and other communities in the Columbia River system.
A spiral tower called a “fish helix” connects baby salmon reared in Cle Elum Lake near Roslyn with the river below the reservoir. It cost $288 million to construct, and was paid for with state and federal dollars.
Previously, the fish had a more treacherous journey over the top of the dam. But the helix is more like a water slide at an amusement park, with a tunnel at the bottom that they glide through. Diagrams of this new structure might remind you of the circular driveways at airport parking garages. It’s a similar shape, though not as large.
During a recent field trip, the helix was nearly submerged by the dam’s reservoir, Lake Cle Elum. A small group of advocates for fish and farmers gathered inside the spiral structure.
The U.S. Bureau of Reclamation was leading the tour, in collaboration with the Yakama Nation. Chad Stuart manages the field office here for the federal agency.
“I don’t know how fast it’s going — looks faster than it is,” he said as the water roared by.
Stuart said this design makes the ride past the dam much gentler for baby salmon on their way to the mouth of the Columbia River system. The fish are sockeye, which were reintroduced to the basin in 2009.
The helix is designed to nurture the instincts of the baby fish to swim upstream and to give them better control as they speed down the helix. Rather than waiting for water levels high enough to push the fish over the dam on the old spillways, the fish are pulled into the helix passages. Once inside, they instinctively swim against the strong current of water rushing downward. That means they end up moving backward down the spiral, eventually getting pushed out the bottom of the helix into the river.
This method has lead to better survival rates than when the fish were spilled over the top of the dam. Urban Eberhard manages the Kittitas Reclamation District, which supports farmers in the basin. He said this project is another good example of the collaboration that has been creating solutions for both agriculture and fish.
“Making better water deliveries, more efficient water deliveries to the farms,” Eberhard said. “At the same time, we are bringing back the habitat and opportunities for our salmon and steelhead production numbers to come up.”
The unprecedented fourth consecutive year of drought in the Yakima River Basin is taking its toll, Eberhard said. It has negative impacts on the agricultural economy and on people's ability to even stay in business. The fish helix provides a beacon of hope.
Joe Blodgett is in charge of this project for the Yakama Nation. He said this is an important step toward reaching the goal of self-sustaining fish runs.
“We will see all of the stocks that were once here, back returning at numbers that we can at least have that hope that the next generation, or generation after that, will continue on and build into the systems,” Blodgett said.
Normally, melting snowpack would allow these fish to move only when the reservoir is full. They would spill over the top of the dam. Now this new structure is taking over for the mechanism that nature previously provided.
With the helix, the fish can meet the water at lower levels and don’t need to wait for full reservoirs to get them past the dam.
That means Washington’s water shortages will be less lethal to these fish, as the ongoing drought challenges the region.
