Hydroelectric dams are considered one of the most impressive engineering wonders of the world. Although hydropower is seen as a clean energy source, dams are not truly environmentally friendly.
In the United States alone, there are over 90,000 dams that generate electricity, control flooding, and provide water for surrounding communities. Notably, there are four dams on the Klamath River (the river famously home to the third-largest salmon population in the U.S.), flowing through the border of Oregon and California.
However, experts have identified a significant issue with these dams. They are detrimental to fish and the water quality of the river. After more than a decade of debates concerning finances, ecosystems, and especially salmon, authorities have called for decisive action. This involves the demolition or removal of all four dams on the Klamath River.
David Coffman, the CEO of Resource Environmental Solutions, stated: “This will be the largest river restoration and dam removal project ever undertaken“.
Close-up of the Iron Gate dam crossing the Klamath River in California. (Photo: Triplicate).
In fact, the Klamath River is renowned for its stunning scenery and impressive wildlife. Stretching over 400 km, it flows through regions of Oregon and California, draining into a basin covering up to 31,000 km². Moreover, the Klamath was once home to the third-largest salmon population on the West Coast of the United States, providing vital resources for local communities.
However, this reality has changed since the construction of hydroelectric dams beginning in the early 1900s. Specifically, between 1895 and 1915, breakthroughs in hydroelectric design led to the construction of numerous dams and power plants, similar to those on the Klamath.
Why Remove Four Dams on the Same River?
The Klamath River was once home to the third-largest salmon population in the U.S. (Photo: Getty Images).
Today, these hydroelectric dams produce enough electricity to power 70,000 homes at peak capacity, although they often do not operate at full power due to low water levels and other issues. Like most major infrastructure projects, the construction of these dams involved trade-offs.
Hydroelectric dams help prevent flooding, generate tax revenue, and create excellent recreational spaces. However, they also obstruct fish from accessing upstream spawning areas, leading to a decline in salmon populations to less than 10% of their original numbers.
Yet, this is not the only impact of the dams. During warmer months, water in dammed areas frequently experiences toxic blue-green algae blooms. This phenomenon occurs when nutrient-rich water becomes trapped in shallow lakes. When developed in sufficient quantities, these algae can be harmful to human health.
The Klamath River has four dams crossing it. (Photo: AP).
Environmental advocates and local tribes have long sought solutions. Meanwhile, some owners are concerned that removing the dams will result in lost tax revenue and decreased property values.
Ultimately, according to PacifiCorp, the removal of the dams will be less costly than alternatives such as building fish ladders and the electricity generated by the dams can be easily replaced.
By 2022, the Federal Energy Regulatory Commission officially approved the $450 million project to remove the four major dams, including Copco 1 and 2, JC Boyle, and Iron Gate.
Experts note that no large-scale dam system has ever been removed like this. Naturally, this project requires meticulous planning and execution to avoid mistakes. It will be costly in the long run, as the ongoing operation costs about $20 million per year to maintain the dams and address current water quality impacts.
Therefore, the demolition of the dams will lead to long-term savings.
How Will the Dams Be Removed?
Illustration of the Iron Gate dam removal. (Photo: Klamath River Renewal Corporation).
Experts indicate that there are two methods for dam removal: instantaneous and phased. The first method, instantaneous removal, occurs rapidly, taking a few hours or days. In this process, specialists will drain the reservoir. This includes releasing water and sediment accumulated behind the dams downstream.
Most dams today have emergency drainage systems in place for quick water level reductions. This system typically consists of a low pipe, open channels for water flow, or a valve (essentially a wooden or beam stack) that can be raised to allow water passage.
After draining the water downstream, the dam will be destroyed using explosives. This stage happens quickly, and the debris will be cleared afterward, taking a bit more time.
Aerial view of the Copco 1 dam. (Photo: CalTrout).
The second method, phased removal, occurs over a longer period, typically several months or years. This method is primarily used for taller dams with larger sediment accumulations that pose environmental risks if released too quickly.
However, during phased removal, the river will be pumped or diverted away from the site through tunnels or channels. This allows for better control over the reservoir drainage process and sediment release.
Once the river is diverted and the basin is drained, the hydroelectric dam will be destroyed using tools such as excavators or explosives (depending on the materials). This gradual method forms the basis for the dam removals on the Klamath River. Adjustments will be made based on the size and materials of each dam. Ultimately, this project will restore a free-flowing state to the river.
In 2023, Copco 2, the smallest of the four dams, will become the first dam on the Klamath River to be removed. Unlike the other structures, Copco 2 does not have a true reservoir, so no drainage process is necessary. However, this process will be conducted for the remaining three dams.
By early 2024, workers will begin opening the low channels to allow these dams to gradually release water and sediment at a rate of 1.5 meters per day. The remaining three releases will occur simultaneously to leverage the water’s force in pushing the water and sediment through.
The Klamath River will then be redirected through new or existing tunnels from when the dams were built. This helps to drain the water and allows for safe dam removal.
After these four dams are removed, the flow of the Klamath River will be restored, benefiting salmon, various wildlife, and the water quality in the area.
