For thousands of years, dams have been a milestone for humankind, yet they’re not engineered to promote the existence of all. Throughout the 20th century and a majority of the 21st century, dams were built across numerous bodies of water throughout California, providing energy for millions. Despite this, waves of research have shown major disadvantages to implementing aquatic energy practices in recent memory.
When dams block rivers, they create an unprecedented disruption in their natural flow. In this process, sediment is trapped behind the concrete structure. Fish that rely on migration, such as salmon, are unable to have access to the area where they reproduce and reside. In addition, temperatures rise in rivers that transform into reservoirs because of their inability to move, making life impossible for cold water species. These concerns about dams are not a new; the relationship between dams and ecological decline has been present in research for past decades. The newer discovery is that the removal of dams is effective. As of 2024, over 2,000 major dams across the United States have been removed, allowing rivers to return to their original flow.
California provides the strongest example supporting the effectiveness of dam recovery. The Klamath River, a 250-mile river that runs from California to Oregon, was once the third largest salmon-producing river in the United States. But in 1918, a series of dams were built along the river, and over the following century, the number decreased. Algae bloom became a recurring problem, and rivers deteriorated the biodiversity of species and other wildlife in the surrounding areas. In October 2024, the last of four dams on the Klamath River were removed, which completed the largest dam removal project in United States history.
The project took many years of planning that began in the early 2000s, which was initiated because of an accidental fish kill that took the lives of roughly 35,000 chinook salmon. Throughout the planning of the river, cooperation between native tribes, organizations, and state agencies in California and Oregon occurred. Data collected in the first year of removal proved to be a drastic improvement. Roughly 7,700 chinook salmon emerged that had been unable to cross for over a century. Water quality improved substantially, as a majority of water before the removal was inadequate for safety levels.
California’s work now and in the future is not limited to the Klamath river. On Malibu Creek, the century-old river is currently in the planning stages of dam removal, a project that is aimed at protecting the California steelhead, a species that has been endangered for almost 30 years. Additionally, two dams on the Eel River have been proposed for removal by PG&E, in an effort to create the longest flowing river in all of California. As the state looks towards flipping the page to the next chapter, breaking down literal barriers is the next course of action.