Tacoma’s main source of electricity decimates salmon populations

Hydroelectric power is better than coal, but it is still ecologically damaging

It seems that we are forced to choose between keeping hydroelectric dams running and protecting the salmon population.

Hydroelectric power is generated through the movement of water. Moving water turns a turbine attached to an electric generator which produces electricity. To make a hydroelectric dam, a large barrier is built across a river to create an artificial lake. This is so the amount of water that pours through the turbine can be controlled to meet increased energy needs or to prevent flooding. Hydropower is praised for its reliability as well as the fact that it does not generate any air pollution. In an age of climate disaster, avoiding greenhouse gas output is important to both humanity and nature’s continued survival.

However, hydropower dams have one large drawback here in the Pacific Northwest: salmon migration. Many of the rivers that are used to generate hydropower are also the rivers that salmon must swim up in order to reach their spawning grounds. 

Since the arrival of white settler-colonists in the Washington area in the early 1800’s, salmon populations have steadily decreased. This is due to settlers violating Native American fishing treaties, habitat destruction, overfishing, water pollutants and hydroelectric dams. Nowadays, Washington state lists 19 major species of salmon as endangered, and 40% of historical salmon runs are now salmonless.

Salmon are known as a ‘keystone species’ in Washington. This means that salmon are so important to the ecosystem that their absence could cause the food web to collapse. In egg form, salmon feed birds and small scavenger predators. Salmon also eat bugs and keep the insect population in check. Salmon are also important to the ocean’s ecosystem. Salmon are the only food source for the extremely endangered Southern Resident orcas that live in Puget Sound and as of July 22 2022, there are only 75 Southern Resident orcas left. When salmon return to their spawning grounds during the end of their life cycle, their bodies feed large predators like bears and eagles. What is uneaten decomposes into the soil, feeding rich sea minerals and nitrogen to beautiful Washington forests. There is no way for human beings to artificially replicate the environmental services salmon produce.

Hydroelectric dams block the flow of a river and prevent salmon from completing their migrations both upstream and downstream. Although adaptive measures such as fish ladders exist, they are still imperfect compared to free passage through the river. Damming up a river also creates artificial lakes. These lakes are not good habitats for salmon due to higher water temperatures and increased amounts of sediment. These lakes can also confuse the salmon and expose them to more predators than normal. In sum, dams are extremely damaging to salmon populations.

Tacoma Public Utilities (TPU) sources electricity from four major hydroelectric projects: The Cowlitz River project, the Nisqually River project, the Cushman Hydro project and the Wynoochee River project. All of these hydroelectric projects have dams built on at least one salmon run. According to TPU’s 2020 Fuel Mix Market Summary, a majority of electricity in Tacoma (54.77%) comes from hydroelectric sources. The next largest category was natural gas, coming in at 12.94%. If all hydroelectric dams ceased operation, Tacoma would require a massive financial investment in alternative energy sources. It is clear that changing Tacoma’s power sources can’t happen overnight.

But that doesn’t mean we shouldn’t start working towards change now. A diversified energy grid is less likely to fail. Increasing the number of wind, solar, and geothermal power sources in Washington state would allow some of the more ecologically damaging dams to be dismantled. Taking down dams and increasing salmon populations in the Pacific Northwest would mean healthier forests, richer soil, and more food for Southern Resident orcas. It would also mean the continuation of numerous spiritual and cultural practices, and would keep thousands employed in local recreation and fishing industries. 

Humans are important, but so is the ecosystem we live in. We should never lose track of how much we still depend on nature in order for our survival as a species. We live in a world worth saving.

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