Unveiling the Impact: The Aftermath of the Largest Dam Removal on Washington’s Wildlife

The series from the O Brother, Where Art Thou movie concluding miracle flood, in reality, was a common occurrence in the 19th-20th century, as river valleys in the American West were dammed and flooded in the name of economic progress and electrification. One such case is Washington State’s Elwha river, dammed in 1910, led to a 40-mile stretch of river being blocked off, preventing native salmon species from spawning. Joe Roman’s “Eat, Poop, Die” chronicles the recovery journey experienced after a 108-foot tall migration barrier was removed from the ecosystem, highlighting the impact of migratory salmon on the Pacific Northwest’s food web.

The Elwha River hosted ten anadromous fish runs including five species of Pacific salmon before the Elwha Dam construction, leading to a decline of 95% in salmon populations in the 1980s. Local wildlife and Indigenous communities were devastated by the loss. After decades of legal efforts by the Lower Elwha Klallam Tribe, the Elwha and Glines Canyon Dams were removed in a $350 million, three-year endeavor which began in September 2011.

Following the removal of the dams, bull trout began migrating back to the ocean, the nearby American dipper and songbird populations increased and a larger mix of wild and local hatchery fish moved back to the river. The success of the Elwha could potentially serve as a catalyst for the removal of other aging dams, such as the Enloe Dam in northern Washington and the Snake River dams, aiming to restore salmon migration.

Beaver dams have also been observed to be beneficial to the salmon population, creating slow-water habitats and altering water temperature in the streams to make them more productive for the salmon. Unlike the concrete dams, beaver dams are dynamic and fluid, helping the salmon to move easily.