For our final week of Orca Action Month’s “Stream to Sea” we continue down the coast to the southern range of the Southern Resident orcas.
The Willamette River in Oregon is part of the Columbia River Basin, contributing 15% of the Columbia’s average annual flow. It flows north for 187 miles and is the largest watershed in Oregon, draining 11,487 square miles. Willamette River spring Chinook are part of the Columbia Basin spring returns and therefore were historically important to Southern Resident orcas.
The Willamette Valley is home to 2/3 of Oregon’s population and it has been heavily impacted by development, urbanization, and industrialization. Pollution is a major concern with high levels of heavy metals, PCBs and pesticides, particularly in the section around Portland which was designated a Superfund site in 2000.
The river is heavily dammed, with 15 large dams and multiple smaller ones on some of the river’s tributaries. The primary function for most of these dams is hydroelectricity, while some provide important flood control and water storage. Poor fish passage at these dams, along with loss of habitat, have negatively impacted salmon. While historical abundance was close to 300,000 spring Chinook, recent averages are fewer than 5000 fish.
In 2008, Willamette Riverkeeper designated the full length of the river as the Willamette River Water Trail, which was then made official and expanded by the National Park Service in 2012.
Significant habitat restoration projects have taken place along the river, and the Willamette River Greenway System now includes over 10,000 acres along the river, most owned by Oregon State Parks.
The Rogue River in Southwest Oregon flows 215 miles from the Cascade Mountain Range to the Pacific Ocean and drains 5156 square miles. The river contains several salmon and steelhead runs, including spring and fall Chinook, summer and winter steelhead, and Coho. Both spring and fall Chinook salmon are included in the Southern Resident Killer Whale Priority Chinook stocks report, and spring Chinook returns overlap when the whales are primarily off the Oregon Coast in the late winter and early spring. Coho in the Rogue River are currently listed as threatened under the Endangered Species Act, and spring Chinook are “potentially at risk.”
While returns are still below desired target levels and fluctuate on an annual basis, generally the status of Spring Chinook is gradually improving.
The river has a long history of dam construction and removal, including a legendary incident involving an early fish-blocking dam that was blown up by vigilantes who were upset by the impacts to salmon. Concentrated dam removal efforts began along the river in the early 2000s, and by 2009, all but one of the main-stem dams had been removed. The one remaining is the William L. Jess Dam which is used for flood control and hydroelectric. It lies 157 miles inland and there are no salmon above that dam. Current ongoing issues in the Rogue River include pollution from stormwater and wastewater runoff, climate change and drought. Since flows in the river are generally quite low, extremes from climate change can be devastating.
The Rogue River is one of the original eight rivers included in the Wild and Scenic Rivers Act of 1968, which is meant to preserve rivers with outstanding natural, cultural, and recreational values in a free-flowing condition. In 2019, 140 additional miles of tributaries were added to the designation.