Is Hydropower Green or Greenwashing?
This post first appeared in our weekly Make Waves Mondays email series on June 15, 2026.
Hello hello friend!
Today's blog is coming to you from your fellow EcoWarrior, Robb Krehbiel. (You may remember Robb from our blog post all about the environmental impact of lawns a few years ago!)
I reached out to Robb about this week's blog topic a couple of months ago after seeing some ads in support of dams, sponsored by Northwest River Partners, that immediately felt like greenwashing to me. I wanted to bring someone in who would know more on the topic to share their knowledge of the sustainability of dams and hydropower, since here in the Pacific Northwest we get a lot of our power from hydro.
I'm so excited for this blog post, and I know that I learned a lot from it, too!
So without further ado...let's dive in 👇
Is Hydropower Green or Greenwashing?
A Guest Post by Robb Krehbiel
Hey everyone! While Krystina is out celebrating her wedding, I'm stepping in as a guest for this week's blog post, and today, we're talking about energy!
One of the things that I love about living in the Pacific Northwest is the fact that so little of our energy comes from fossil fuels. In other states I have lived in (Iowa, Kansas, Maryland, Montana), so much of their energy comes from coal and natural gas, which means they not only generate more CO2 emissions than states like Washington, they also have a lot more to invest in clean energy to replace that energy.
Here in Washington State, over 70% of our energy comes from hydropower.
In Tacoma, we get a mix of power from hydropower dams owned and managed by Tacoma Power and energy purchased from Bonneville Power, which is one of the managers of the dams on the Columbia and Snake Rivers. So if you're mostly interested in reducing your carbon footprint, you may look at hydropower and say, "Great! Problem solved! More of this, please!" While hydropower gets high marks for being carbon-free, it isn't without its issues.
Hydropower dams have been a concern for environmentalists for generations. The Sierra Club, America's oldest environmental organization, was formed when its founder, John Muir, organized opposition to the Hetch Hetchy Dam, which (despite strong opposition) was built inside Yosemite National Park, flooding Yosemite Valley and disrupting the river's ecosystem. Like all ecosystems, rivers are dynamic. Their health depends on their ability to meander freely through a floodplain, rising and falling with rainfall and snowmelt. Swift-flowing rivers move sediment and nutrients, provide diverse habitats for aquatic wildlife, and keep waters cool for fish (like salmon) who rely on them.
Dams not only disrupt all of this, they are also a physical barrier to species navigating the river.
Image of the Detroit Dam in Detroit, Oregon by Dan Meyers via Unsplash.
So what happens when a dam gets built?
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First, the dam holds back water that used to flow freely downstream. This water floods the land behind the dam and slows swift currents into slack reservoirs that make the river look more like a lake.
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With the river coming to a halt, the sediments and nutrients that used to flow downstream build up behind the dams' wall, which means there's too much behind the dam and not enough below the dam. This leads to algal blooms because of the excessive nutrients and dead zones because of the lack of nutrients.
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Slack water, like that in the reservoirs behind dams, also absorbs heat better than cold water does. When water is still and sits exposed, it gets hot, which is a big problem for species like salmon who evolved with cold water in rivers. As water warms, salmon get more sluggish, and if it gets too hot, they can die before reaching their spawning grounds.
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Perhaps the most visible impact, though, is the physical barrier that dams create. Species like salmon, trout, sturgeon, and eels rely on rivers to move between the ocean and their freshwater spawning habitat. While some dams have found ways to help salmon get around dams, these tools don't work for every fish that uses the river, especially sturgeon and eel who don't use fish ladders.
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Over the long-term, all of these changes make rivers less resilient to climate change. In order to change and adapt to a warming world, rivers need to be able to change and adapt. They can't do that if they are blocked by dams.
Effects of Dams on Tribal Lands
On top of all of the environmental damage done by dams, most of the dams that power our lives in the Northwest were built without the consent of the Tribal nations who have lived in the region since time immemorial.
Many dams were built without consulting the Tribes at all, which meant many severely impacted indigenous communities and culture. The Elwha dams on the Olympic Peninsula flooded the site of the Elwha Tribe's origin story (fortunately these dams have later been removed). Dams on the Columbia and Snake Rivers flooded rapids and small waterfalls where indigenous people would gather to fish and trade. The most prominent of these sites was Celilo Falls on the Columbia River, which remains submerged to this day.
And because all dams impact salmon, a critically important species and treaty-protected resource, Tribal communities are often forced to deal with the negative impacts of these dams without benefiting from them.
Image of the Elwha River Dam from the Washington Department of Energy via NPS.
Benefits of Hydropower
Hydropower dams do have their benefits.
Many were built during the New Deal era, putting Americans to work and generating some of the cheapest energy in the nation, which later fueled the development and growth of the Pacific Northwest.
Dams also create "river highways" for ships and barges that need slow and calm waters to transport wheat grown in Idaho and eastern Washington to the Ports of Tacoma and Seattle (where much of it will be loaded on cargo ships bound for Asia).
Other dams made it possible for cities in western Washington to grow. Without the Howard Hanson Dam on the Green River, people living in Auburn, Kent, Des Moines, and Renton would be dealing with continuous floods, making them inhabitable for people.
And of course, the energy that dams provide us is carbon-free, which is incredibly important as we combat climate change and see an ever-increasing demand for electricity (from EVs to AI data centers, we are using MORE energy, not less).
So what's the path forward?
What is an eco-conscious northwesterner to do? A few suggestions:
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Use less. No matter where your energy comes from, the best thing any of us can do is use less energy. Every type of energy generation comes at a cost (coal creates CO2, dams harm rivers, solar panels require rare earth minerals, wind turbines disturb birds and bats, etc.). There isn't a fully "green" way to create energy, so the best thing we can do is to learn to live with less.
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Increase efficiency. When you do use energy, use it as efficiently as you can. If you can invest in them, look into energy efficient appliances, hybrid hot water heaters, and heat pumps. Look for products with the Energy Star certification to know you are getting the most energy-efficient tech you can.
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Diversify our energy grid. While it may be cloudy for a lot of the year, the Pacific Northwest still has a lot of potential to generate a lot of its energy through solar, which is something homeowners can install on their roofs. The solar panels on my roof generate more energy than I use in the summer, and the excess is sent to the Tacoma power grid. This reduces our overall dependence on hydropower in the summer (and I get credit on my utility bill in the winter for the energy I sent to the grid). Even if you can't install solar on your roof, you can support local and state efforts to increase the amount of wind and solar energy being generated in Washington.
As with most things, hydropower is complicated and complex.
Ultimately, though, our region would be healthier and more resilient if we relied less on hydropower and could remove more dams to let rivers run free. Fortunately, the power is literally ours: we can reduce our use of electricity, be more efficient with it, and find other ways to generate it.
Taking these steps can make a big difference for the future of our rivers, our salmon, and our region.
Get to know Robb!
Robb has worked in environmental planning and natural resource management for over a decade. As an environmental planner, Robb is passionate about bringing nature back to our urban communities and reshaping our relationship with nature. He has worked across the west with environmental nonprofits, including the campaign to remove the lower Snake River dams. Robb is currently an environmental planner for the state of Washington, serves as the Chair of Tacoma’s Planning Commission, and volunteers to plant trees and steward his neighborhood park.
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