Underwater Tower and Fish Collection Facility Nears Completion
For the first time in 40 years, salmon and steelhead could soon be swimming their way down the Metolius, Crooked, and upper Deschutes rivers as a result of new equipment now in advanced stages of construction, according to an Aug. 25 press release.
Portland General Electric and the Confederated Tribes of the Warm Springs Reservation of Oregon, co-owners of the Pelton Round Butte Hydroelectric Project, will be restoring fish passage around the Pelton and Round Butte dams on the Deschutes River through a 273-foot underwater tower and fish collection station.
The new underwater tower is designed to modify currents and temperatures to mimic natural conditions and attract migrating fish into the collection facility. These fish will be sorted, and young salmon and steelhead will be trucked downstream below the dams to continue their journey to the Columbia River and the Pacific Ocean. When they return as adults, the fish reaching the lowest dam will be sorted, and the salmon and steelhead will be trucked above Round Butte Dam to reach the upstream rivers to spawn.
"This is an innovative solution to restoring fish passage in the Deschutes River Basin," said Stephen Quennoz, PGE's vice president of power supply and generation. "With this new facility, we will be able to continue providing an important source of clean, renewable power for the region while being good stewards of the environment."
"This new tower is the result of a commitment the tribes made 10-plus years ago when re-licensing was in its infancy. This helps restore a fishery that has been a vital part of our culture," said Bobby Brunoe, general manager of natural resources, Confederated Tribes of Warm Springs. "An abundant, vibrant and healthy river also supports the numerous benefits to the river and its reservoirs."
Construction on the project, which is located above Round Butte Dam in Lake Billy Chinook, is under way with crews on target to have the facility constructed and operational in spring 2009, at a cost of about $108 million.
The tower is the only known system to combine fish collection and water flows for power generation. After years of research, PGE and the Tribes have chosen a design that makes Pelton Round Butte an important source of green energy for Oregon. The structure, called the "Selective Water Withdrawal Tower," is designed to draw water from the surface and the bottom of Lake Billy Chinook. This will change the currents of Lake Billy Chinook to attract fish into the fish collection facility; lower the temperature of the lake, providing healthier conditions for the fish; modify the temperature of the lower Deschutes River to more closely match what it was before the dams were constructed, and improve the water quality in the reservoirs and in the river.
In addition, 100 percent of all powerhouse flows are screened to protect the fish. There is a series of supporting projects to improve environmental conditions for the fish, including:
• releasing salmon and steelhead fry into upstream creeks and streams so they will return there to spawn once the project is complete.
• improving habitat along the tributaries and streams so returning adult fish can spawn and young fish can thrive.
• monitoring the way fish use different habitats upstream, how they interact with existing fish populations, and the effectiveness of the various fish-passage facilities.
The tower is being designed by CH2M Hill, EES Consulting, and ENSR/AECOM Technology Corp. in collaboration with PGE Engineering; and constructed by Barnard Construction Co., Dix Corp., and Thompson Metal Fab.
A microsite has been developed for the project. To read the unfolding story, visit www.DeschutesPassage.com.
Pelton Round Butte, the largest hydroelectric project within Oregon, generates 465 million watts capacity of electricity to serve PGE customers and the Tribes. It is the only hydro-electric project in the nation jointly owned by a Native American tribe and a utility. Its total annual power production is about 1.5 billion kilowatt-hours, enough to power approximately 137,000 homes or a city the size of Salem, Ore. The project constitutes 9 percent of PGE's power generation mix.
With the new structure and restoration of fish passage on the Deschutes, the Pelton Round Butte hydro project has been certified by the Low Impact Hydropower Institute as a source of green energy. Fifty megawatts of the Pelton Round Butte hydro project will be counted as part of PGE's renewable energy portfolio.