They’re beautiful, if you haven’t seen them.
Analogous to the archetypal American wilds, Chinook salmon, also known as king salmon, were driven to the edge of extinction in the Pacific Northwest in the 1990s because of a century’s worth of environmental degradation at the hands of American expansionism. Increased runoff and erosion from anthropogenic activities had polluted their rivers; industrial construction had blocked their paths home; warming waters had robbed them of their freshwater food sources.
In the Klamath River, which flows for 260 miles between Oregon and California, these kings had all but disappeared. Yet in 2024, they began to return, thanks to conservation and rewilding efforts. A recently released study in Scientific Reports showed that the 2025 spawning season counted a migratory population of 13,000 Chinook salmon, a 72% increase from the 2024 season. More hope has been given by the success of springtime spawning — the study confirmed that after a century of depletion, the first juvenile Chinook were observed in the upper basin.
The secret of this unprecedented success has been the removal of the four Klamath River dams — the result of a nearly two decades’ worth of advocacy, made famous through Patagonia’s award-winning “DamNation” documentary. The removal of the dams in the region also coincided with a return of Indigenous food sources, an increase in water quality and a removal of toxic cyanobacterial blooms.
To many, the removal of a dam being considered an environmentally friendly initiative may come as a surprise. Hydropower has been ingrained in the popular imagination as a figurehead of green energy, which captures the power of rivers to generate electricity for vast swaths of our nation.
While dams may not burn fossil fuels, they are far from being “green” energy. By their nature, dams raise water levels, causing an immense buildup of sediment that can not only hinder energy generation, but can also slow the flow rate of rivers. The resulting slow-moving water traps heat and lacks oxygen. These stagnant reservoir pools also disorient fish during migration, disrupting their reproductive cycles. These conditions culminate into intense organic stress that can damage the health of aquatic species and can lead to die-offs.
Dams affect the physical environment of rivers as well. Trapped debris –– such as gravel, logs and other natural sediments — is prevented from traveling downstream, where it can form the complex riffles and pools needed to support healthy river systems. Also prevented from dissemination are the vital flow of nutrients like carbon, nitrogen, silicon and phosphorus which traditionally flow through the river system. Consequently, sedimentation build-up in reservoirs leads to increased nutrient retention upstream, leading to harmful eutrophication. Erosion can also increase downstream due to high water pressure released intermittently from dams, destroying local habitats and disintegrating riverbanks. This degradation can later lead to flooding and the destruction of surrounding forests, doing away with a vital carbon sink.
Dams are not without emissions either. Globally, dams contribute roughly 1.3% of the world’s annual greenhouse gas emissions, as much as the entire nation of Canada. This is partially a result of methane release from trapped sediments. Dam infrastructure also wastes water — negating away with the argument that they are a necessary evil for global water consumption. As a result of the wider surface area, increased transpiration and slower flow rates of reservoirs, dams lose over 170 cubic kilometers of water to evaporation each year. This number is equivalent to around 7% of all freshwater consumed by human activities per year.
Critics of dam removal argue that the disposal of the infrastructure is hazardous to the environment and necessitates avoidance. This logic makes sense. Many dams were born out of an industrial past and as such have been severely contaminated with pollutants. Tailing dams in particular often have noxious sludge buildup as a result of chemical waste and runoff. Critics argue that removing dams would release these sediments outwards, polluting any areas downstream of the site.
This concern, though well founded, fails to account for the fact that dam breaches are already remarkably common. Roughly 70% of dams in the US are over a half century old and surpass their expected life expectancy by decades. As a result, system failures are becoming more common as our nation’s infrastructure continues to age. Furthermore, toxic minerals have been shown to escape into the soil through acid draining and microbial consumption, thereby negating the utility of dam storage. By choosing to neglect the safe removal of these aging dams, an already hazardous situation is only exacerbated.
Globally, 97% of rivers have been impacted or fragmented because of dam infrastructure. The success of the Klamath River restoration project and the resulting return of the king salmon shows the clear benefits of removing these misguided feats of human ingenuity. Though the restorative process is still in its infancy, the projected long-term benefits provide a strong argument as to why our nation’s aging dams must be removed. Policymakers must look towards the Klamath River as precedent for why our waterways must be saved.