In the iconic film O Brother, Where Art Thou, our heroes are miraculously saved by a man-made flood at the end of the movie. This might seem like an unrealistic event, but in reality, such floods were a fairly common occurrence during the 19th and 20th centuries in America. These floods were the result of damming up river valleys, which led to the drowning of vast expanses of land in the name of economic progress and electrification. One such example is the Elwha River in Washington State, which was dammed in the 1910s. While the dam provided economic benefits for the region, it also blocked off nearly 40 miles of river from the open ocean, preventing native salmon species from making their annual spawning trek.
For decades, the Lower Elwha Klallam Tribe fought legal battles to have the dams removed. The tribes’ efforts were finally successful, and today, the biggest dams on the river are the ones made by beavers. In Eat, Poop, Die: How Animals Make Our World, University of Vermont conservation biologist Joe Roman explores the impact of removing a 108-foot tall migration barrier from the local ecosystem. The book delves into how nutrients flow through the Pacific Northwest’s food web and the myriad ways it is impacted by migratory salmon. It takes a fascinating look at how the most basic of biological functions can potentially impact life in every corner of the planet.
The Elwha Dam, which was built in 1910, was part of an effort to attract economic development to the Olympic Peninsula in Washington. However, by blocking the majority of the watershed from the ocean, it led to a 95% decline in native salmon populations and devastated local wildlife and Indigenous communities. As a result, the Lower Elwha Klallam Tribe and environmental groups lobbied for the removal of the dam, leading to the Elwha River Ecosystem and Fisheries Restoration Act being passed by Congress in 1992.
The demolition of the Elwha Dam began in 2011 and was the largest dam-removal project in history, costing $350 million and taking about three years to complete. The removal of the dam resulted in a quick and positive response from the fish and local wildlife. Species such as bull trout, steelhead, and Chinook salmon saw their populations increase, and previously dormant migratory patterns were rekindled. The removal of the dam also led to a resurgence in surrounding wildlife, such as the American dipper and songbirds.
The success of the Elwha Dam removal has set a precedent for the potential removal of other aging dams, such as the Enloe Dam in Washington, and the potential breaching of the Snake River dams to save endangered salmon in Washington State. The restoration of salmon migration could have far-reaching effects, benefiting not only the local ecosystem but also endangered species such as the critically endangered killer whales off the coast of the Pacific Northwest.
In addition to the removal of concrete dams, the introduction of beaver dams has also been instrumental in restoring salmon habitats. Beaver dams create new slow-water habitats that are crucial for juvenile salmon, and their dynamic and heterogeneous landscapes allow for easy salmon travel. These efforts have shown that nature can recover remarkably quickly once human-made obstacles are removed.
Overall, the story of the Elwha River serves as a remarkable example of the resilience of nature and the impact of human intervention on ecosystems. It also demonstrates the potential for the restoration of natural habitats and species through careful, considered action.