The Willamette River is the 10th largest river in the lower 48 states. In 1889, we built the first hydroelectric plant in the American West, Station A, at Willamette Falls in Oregon City, south of Portland. It was replaced by the T.W. Sullivan plant in 1895, which has generated electric power ever since as PGE’s Willamette Falls Hydroelectric Project.
Over the decades, PGE has continually updated the Project so that today, it is an essential source of power for PGE’s customers. Read more about the history of the project, and about PGE’s efforts through the decades to continually enhance the health and welfare of fish in the Willamette River.
The Low Impact Hydropower Institute Board certified the Willamette Falls Project in 2008 as low impact, and renewed its certification in 2012. The designation is based on PGE’s extensive fish protection efforts and passage improvements, including installation of a second fish bypass system at the Sullivan plant and construction of the flow control structure at the apex of Willamette Falls.
This designation means the Willamette Falls Project is a recognized producer of low-impact hydro power, joining PGE’s Pelton Round Butte project as two of only a few dozen hydro projects in the U.S. to have earned this distinction.
Before development, Willamette Falls presented a natural seasonal barrier to migrating fish. Spring Chinook salmon and winter steelhead were the only two species that could ascend the falls in later winter and early spring, when flows were sufficiently high.
In a letter to the editor of The Oregonian on Aug. 12, 1870, a writer suggested that the Legislature build a fishway over the falls. He wrote that “salmon are found in all the waters of Oregon except those of the upper Willamette.” In 1885, the first adult fish ladder was excavated out of the solid rock at Willamette Falls. Though primitive, this ladder did help fish move above the falls.
Technology and knowledge of fisheries advanced over time, and the Oregon Department of Fish and Wildlife designed the current fish ladder, which was completed in 1971. Since receiving our new federal operating license in 2005, PGE has performed maintenance on the fish ladder to ensure it continues to operate effectively. We’ve increased maintenance of the state-owned ladder, installed a new adult lamprey passage system, and replaced 11 of the plant’s 13 turbines with highly efficient, fish-friendly turbines.
Today, our fish passage systems facilitate both upstream and downstream migration year-round for several species of salmon and lamprey.
PGE’s hydropower project at Willamette Falls
Between 2005 and 2008, PGE installed a flow control structure at the apex (the most upstream point) of Willamette Falls, and a bypass chute (a water slide for juvenile fish) at the Sullivan plant, to help salmon complete their journey to the Pacific Ocean.
Flows entering the plant are managed so that fish within the water column are guided past the turbine intakes and into a long concrete water slide that directs them back into the Willamette River just downstream of the falls.
Juvenile fish successfully pass over the falls and through PGE’s facilities using this bypass chute.
The 200-foot-wide gated flow control structure, located at the tip of the falls, features concrete piers and three 10-ft diameter inflatable rubber gates. These structures help fish avoid hazardous rocks by guiding them to the deep water at the base of the falls for safer passage.
These fish passage enhancements have improved the success rate for migrants on their way to the Pacific Ocean. We’ve reached a 99% survival rate for juvenile fish passing through our powerhouse. In fact, going through our facilities is the safest way for fish to pass downstream of Willamette Falls.
In 2008 and 2009, PGE fisheries biologists tagged or micro-chipped over 15,000 fish in two studies at the Project. Results show fish survival rates in excess of 98 percent at the powerhouse and 97 percent at the falls.
Spring Chinook move through the Willamette Falls ladder between March and July, spawning in September and October.
Four large hatcheries above Willamette Falls produce about 8.8 million smolts each year (spring and fall Chinook), plus additional fingerlings to seed reservoir and stream areas.
About three-quarters of this hatchery production is funded by the Army Corps of Engineers as mitigation for lost production areas. The percentage of wild fish in the present run is unknown but is estimated at 5-15% of the total.
Fall Chinook salmon were introduced above Willamette Falls in 1964, after upstream fish passage was improved.
Releases of the early spawning (tule) stock ranged from 5 to 12 million smolts annually. The state discontinued releasing hatchery fall Chinook in 1996.
Tule fall Chinook pass Willamette Falls from mid-August through late September on their way upstream. Fall Chinook spawn in the main stem Willamette River and lower reaches of eastside tributaries. Natural production comprises about 28 percent of recent runs.
The construction and successful operation of fish ladders in the Willamette made it possible for coho salmon to migrate above the falls.
Migrating over the falls from August to November, they spawn in October and November. Efforts to establish coho above Willamette Falls began in 1952.
The run never reached expectations, and hatchery introductions were de-emphasized. Recently, this naturalized population has established with annual returns of more than 11,000 fish.
The Willamette Falls fish ladder allows summer and winter steelhead to pass over the falls. Summer steelhead were introduced in the late 1960s to provide sport-fishing opportunities.
They move upriver from March to October and spawn in January and February. Hatchery spawning occurs January through March, and year-old juveniles are released mid-April through early May.
The native Willamette winter steelhead stock is a late run, passing Willamette Falls from February through May. To expand angling opportunities, Big Creek Hatchery stock were introduced in the 1960s.
These fish return in December and January and have established naturally reproducing populations.
PGE has spent decades researching Pacific lamprey.
Like salmon, Pacific lamprey are anadromous — they are born in freshwater, migrate to the ocean, and return to freshwater to spawn. They are a traditional food source for Native Americans who harvest them at Willamette Falls.
The Willamette Basin is probably the most important production area for Pacific lamprey in the Columbia River Basin.
Daily counts of winter and summer steelhead passing Willamette Falls are available online from the Oregon Department of Fish and Wildlife.