Think Out Loud

Elwha River transformed 10 years after dam removal

By Elizabeth Castillo (OPB)
Aug. 2, 2022 5:29 p.m. Updated: Aug. 2, 2022 8:48 p.m.

Broadcast: Aug. 2

An image of trees, a mountain and water flowing through an area in Washington.

Areas affected by dam removals on the Elwha River continue to thrive.

Chhaya Werner


For about a century, the Elwha River in Northwest Washington was broken up by two dams, to generate power to Port Angeles. The Elwha Dam was removed in 2012 and the Glines Canyon Dam was removed in 2014, creating a transformation in the natural ecosystem. Fish are returning, and vegetation in the region continues to thrive. Chhaya Werner examined vegetation regeneration in the affected areas and documented how plants responded to a free-flowing river. She has visited the region many times over the last decade, observing the changes. Werner will begin teaching at Southern Oregon University in the fall as an assistant professor of ecology. She joins us with details of the region’s transformation.

Note: The following transcript was created by a computer and edited by a volunteer.

Dave Miller:   For about a century the Elwha River and northwest Washington was broken up by two dams. Then came the largest dam removal project in US history. The Elwha Dam was taken down in 2012. The Glines Canyon dam was breached two years later. So over the last decade or so, the L. A. River has become an exciting source of data. Scientists have had front row seats to chart the rapid transformation of an ecosystem. Given that an even larger dam removal project is in the works right now, the four dams on the Klamath River are slated to be breached in the next few years. We wanted to get a sense for how the Elwha Basin has changed. We’re going to get two perspectives this week. On Friday, we’ll talk to a longtime biologist with the Lower Elwha Klallam Tribe. Today we are joined by Chhaya Werner. She’s a Plant Community Ecologist who is about to become an Assistant professor at Southern Oregon University. She has visited the Elwha River many times over the last decade. Welcome to Think Out Loud, it’s great to have you on. What first brought you to the Elwha River? What were you most interested in learning?

Chhaya Werner:  That’s a great question. When I started studying plant ecology, I was really interested in succession, which is how after some kind of disturbance, plant communities change over time and you have different sets of species coming in and kind of growing one after the other. And we can think of this happening a lot after fire or logging or on Mount Saint Helens after volcanic eruption. And in cases like that, it could be really, really slow. So dam removal was this exciting scenario that we don’t get to study very often, especially on the scale of the Elwha River where, because the lakes had been there so long, it was almost like starting from a volcanic eruption, where you’re starting from the bare soil. There’s no trees resprouting, there’s not a lot of seeds present there, but then it’s a really rich area and a really productive area, so it happens a lot more quickly. And so you can study changes over the course of just a few years, whereas something like a volcanic eruption would take decades to see all those changes.

Miller: Can you remind us why the dams on the Elwha River were taken down in the first place? I mean, why were they good candidates for breaching?

Werner:  Absolutely. The Elwha dams were over 100 years old and they had been built at a time that there were no fish passages added in at all. So this really beautiful productive watershed had basically been stopped really close to the mouth of the river and the salmon couldn’t get upstream. And my understanding is also that because of their age, the Dams had a lot of structural issues. So there was work, one way or another, that was going to need to be done to keep them. And so there was an act of Congress that actually approved dam removal in 1992. And that was after a lot of study into whether fish passages could be added or not and would it be sufficient? Then it took a whole another decade of work to figure out how to do the removal before the project finally started in 2011.

Miller:  You’ve been focusing on two sites that were once reservoirs or lakes. What did they look like the first time you went?

Werner:  I first got to visit the reservoirs in 2013. One of them had been drained for about a year and a half. And the other one was kind of halfway through that process of getting the dam fully removed. They were really interesting. A lot of it was very moonscape. All the sediment had been exposed after almost 100 years underwater. So in the afternoon we would get dust storms where you needed to wear sunglasses or the substrate would just blow straight in your eyes as you were walking. But there was also a lot growing already. There were these patches of bright green, especially rushes and grasses coming up. And then one of the really cool things is there were stumps everywhere from when the area had been logged before the dams were constructed and they’d all been preserved under the water.

Miller:  So 100 plus year old stumps of the trees were way older?

Werner:  Yes, giant original old growth forest logs and you can still see them. You can still see the cuts where the logging was done and they were just preserved under water that whole time.

Miller:  So I want to hear about the intervening years, but I’m curious about when you look now what you see?

Werner:  Now it’s such a joy to visit the area because it’s so lush, it’s so green. I was talking about a lot of the succession all stages that I was interested in have happened. And so you have really large riparian trees, alder and cottonwood. There’s a huge diversity of native flowers as well. There’s riverbank lupine and wooly sunflower and sage, brush roses and berries. And then there’s a lot of conifers coming into the areas that you would kind of expect to slowly have this conifer recovery. So it’s really neat to see all of that progressing.

Miller: When you were there at the beginning and in the afternoons, sometimes the wind would whip up and the dust would blow. Did you get the sense that that potentially productive soil was just going away?

Werner:  No, actually, I think a little bit the opposite. So one of the issues with the dams is that they blocked all of the sediment that normally moves in the natural flow of the river from upstream to downstream. And so one of the really great things that removing the dam did is it actually restored the delta where the River meets the Strait of Juan de Fuca and rebuilt this entire beach and lagoon area that had gotten deprived of all of this sediment. So seeing all that soil moved downstream was part of the process.

Miller: Interesting. So in other words, that’s also evidence of a larger view of the ecosystem, not just in these sort of newly drained no longer reservoirs, but, but the entire river system. You’re saying that nutrients and soil were finally being delivered to places where they had been, in a sense denied for a century?

Werner:  Yes, absolutely.

Miller:  When you were mentioning the trees and the plants that you saw - riparians and alder and cottonwood and various flowers. How many of those were the results of human planting or replanting and how many were where nature could just take its course?

Werner:  A lot of both. So a lot of the areas that I studied when I was collecting data were the areas of the park where the folks working in the park had decided to leave to regenerate naturally. And those were a lot of the areas that were kind of closer to where the edges of the lake had been, on the walls of that reservoir. That’s where some of the richer soil was and closer to seed sources. And so especially like the alder and cottonwood, and the willow, those came back really well in those areas.


But there was also a phenomenal effort led by the National Park Service and the Lower Elwha Klallam Tribe to generate native species as well as to plant them out. So there was a nursery that ran for, I think, about five years.  They ended up growing up over 300,000 plants that they then planted and seeded out into the reservoir. And that was a lot of work by volunteers as well as the folks working for the Park and working for the Tribe. And so a bunch of the conifers in particular were planted out in areas where they thought it would take them otherwise decades to get to, [in order to] give that succession process a head start.

Miller: And what was the thinking? If that hadn’t happened, that really large multi-year process that created 300,000 trees to actively plant if that hadn’t happened, what do you imagine that land would be like right now?

Werner:  I think it would be different in a couple of ways. One of them is that you would see a lot more invasive species. There’s particularly some non-native species in the area that can take over in a way that prevents anything else from growing. And so there was a lot of active removal of invasive species to prep the area even before the dam removal started as well as during the process. And then I think there would be areas like the bottom of Elwha where it’s much rockier, it’s much more like a riverbed. It’s really big and open where you actually wouldn’t have very much growing at all. And those were areas where planting was targeted. They also seated a bunch of species including a native riverbank lupine that took over and is now making the environment more conducive to other plants growing by fixing nitrogen and helping stabilize the soil and providing shade and bringing in wildlife and all of that. So I think there were certain things that went really well and are really helping with having that lush transformation get sped up so we can kind of watch it happen year to year. This accelerated, right?

Miller:  This reminds me that in the last part of the show today we’re gonna be talking with a geneticist who works for the U. S. Forest Service in Washington and Oregon who’s focused on a white bark pine restoration program. There are some real parallels in some ways in terms of this conversation and that future one. So stay tuned for another interesting conversation about the interactions between humans and trees. I should remind folks. So right now we are talking about the Elwha River 10 years after two dams there were removed.  Warner is an assistant professor of Ecology at Southern Oregon University who’s focused on plant communities. As I noted, you focus on trees and plants, but you did mention wildlife there. Can you give us a sense for how wildlife, how animals have changed over the last decade?

Werner:  I can give you my un-expert opinion on that as I’m not a wildlife Ecologist. But my understanding is that a lot of the salmon populations have made it back to the areas above where the dams were. Especially the chinook and chum salmon are doing really well.  I’ve also been out there and seen all sorts of birds, waterfowl, eagles foraging in the river. There’s amphibians everywhere. There’s frogs and salamanders that are taking advantage of this new riparian space. There’s definitely been large carnivore sightings. Last time I was hiking out there, we found a deer carcass. So something definitely took that down. And then the birds I think are especially important because they help spread a lot of the seed and kind of amplify the restoration work and the planting work that was done, by spreading those seeds of the flowers and the berries throughout the reservoirs.

Miller:  You noted that at the beginning you were really excited to see a real life version of succession, of the different stages that an ecosystem could go through. I’m curious how much of what you’ve actually seen either meshes with or goes against what you might have read or now maybe are teaching in textbooks. I mean is the Elwha River behaving the way you thought it would?

Werner:  I would say in a lot of ways, yes. There’s certain areas like where the cottonwood and the alder are really thick, where you can really see they went from being little trees to competing with each other. And you have this phase where the trees that don’t get tall enough, don’t get enough light die off and thin out. So you’ve got fewer bigger trees and now we’re at the phase where there are a lot of trees that just grew up really straight and tall and so they’re actually not supported anymore because they were competing so hard for that light and those then fall over. So you have another round of this natural thinning. And you end up with this really much more open space with fewer bigger trees. So that was really interesting.

Something else that fit a lot with what I think of as classically called ecological theory is that one of the things the National Park Service did, and especially Josh Chenoweth leading the re- vegetation team did, is actually had helicopters move wood around - a lot of the driftwood that was in the lake. And some of that was to create salmon habitat. But a lot of it was to actually move that wood into places where it would be too open, otherwise, for plants. And so even now you can see each of these logs then has this little sheltered area where there’s a whole bunch of plants growing along it and taking advantage of that stabilizing and shading area. So we’ve seen facilitation with the lupine.

I think the big thing that’s been surprising to me is how well some of these planted conifer trees did, especially the ones that have been out there for nine years. So they survived last year’s heat dome. It’s just not an area that I would expect to be really hospitable to little conifer seedlings. A lot of them have died, but the fact that so many of them have survived and are still hanging on was really impressive and surprising to me.

Miller:  In 2016, you wrote in a blog post, “the last two summers, the story of the reservoirs has been one of abundant growth and forward progress this spring revealed a more complex path taken by nature as destruction becomes part of the very process of restoration”. What kind of destruction were you talking about?

Werner:  In the process of restoring the River one of the great things about removing the dams is that the river, both upstream and downstream, is free to move more. And so as it’s been resettling and changing through these floodplains. That’s great. That’s a wonderful part of the natural system. The consequence for the Park and the human side that’s been a little unfortunate is that the River has completely washed out the road that used to go up to Mills Reservoir, as well as two of the Park’s campgrounds. And so when I wrote that blog post, I [had] just visited one of these campgrounds and there were these enormously heavy cement concrete picnic tables that had been completely upended and washed down the stream.

And there were campsites that were buried four or five feet deep in sediment. And that’s progressed, actually, a fair amount since then. So those campgrounds are closed, but more and more of the road has been washed out. The Park has added a hiking trail so people get around. But I think the unfortunate part of that is that, especially, Mills Reservoir is not as accessible for a lot of people. And so it’s this really great place where anyone who knows and has the ability to get there can watch these amazing things happen. But I’m really hoping that at some point, the Park’s able to either put in an alternate road or add a shuttle or something so that more people can see all the changes that are going on.

Miller:  Is there a lesson here though, that we can’t have everything? I mean for 100 years these rivers were highly managed and it meant that land was submerged and all of the kind of the natural life of a river was denied it. Now with the river not managed that way, it’s going to meander more, braid more, flood more and do its own thing more. Is that just sort of the part of the cost of dam removal?

Werner:  Absolutely. In Europe, one of the terms that gets used for restoration a lot is rewilding. and I like the aspect of that that we have to embrace, which is that if you make the river wild again, then it will actually be wild and it will move around more and we just have to accept that and live with that and appreciate that.

Miller:  As I noted, you’re about to start a job as a professor of Ecology at Southern Oregon University, not that far from the four Klamath River dams that are scheduled to be taken out in the next few years. And that if it happens, it’s going to become the largest dam removal project in US history. How actively do you plan to study that?

Werner:  Yes, that’s right. So I’m going to be really close to the Klamath dams. I am super excited to even just personally watch that happen. I’ve connected with some of the folks who are working on the revegetation of the reservoirs because that’s the part that I’m most interested in. And we’ve already started to talk about what some useful collaborations might look like. I’m particularly excited. I think it’ll be a great opportunity for students at SOU because it is such a local project to be able to take them out on field trips and support some of the undergrad thesis work that they do on the study too. And that’s something that worked really well with the logjams. There were a lot of people who did undergraduate and master’s work that then contributed to the Park’s understanding of little slices of what was going on in the system. So I’d love to be able to facilitate and support that as well on the Klamath.

Miller:  Do you think that what’s happened in the last 10 years that you and others have been documenting, does it provide lessons for what could happen in the Klamath Basin?

Werner:  I think it does. One of the great things is Joshua Chenoweth, who’s one of the people who led the revegetation work on the Elwha, is now also very involved in the Klamath project. And it’s particularly fun to chat with him about it. I think there’s a whole bunch of lessons that were learned and taken away. But there’s also a recognition that the climate system is very different. The Elwha is a watershed primarily within the Olympic National Park, where the Klamath primarily goes through active range lands and private lands. And so there’s a whole mix of other nutrients influxes, cattle impacts, different species, different challenges with heat and drought than we have to deal with in the northern pacific Northwest. And so I think everybody’s being really humble, but in a lot of ways it will be a brand new learning curve. But also I think seeing how successful the Elwha restoration was and how exciting that has been and how connected people have gotten to be in being able to volunteer and being able to help and being able to see that process. And so I think there’s a lot of hope that that kind of pattern could play out in its own way on the Klamath as well.

Miller:  Finally you tweeted out back to back photos recently from 2013 and 2022. Those photos were retweeted 1000 times or so and liked nearly 9000 times. Why do you think these photos resonated so much with people?

Werner:  I’m not entirely sure. It was surprising how much attention those photos got. I think particularly, you know, this time in the last couple of years there’s been a lot that’s been really hard. And I think the amazing thing about restoration is that we actually get to see something that’s beautiful and that’s getting better. And just having that moment of being uplifted and encouraged in a world where it feels like there’s all these challenges that we’re facing, especially with environmental issues. I think the great thing about restoration is that it reminds us that we can make things better by actively engaging with nature, especially when that work is led by the Tribe and by local folks doing amazing work. It’s a little bit about restoring the land, and it’s a little bit about restoring our connection and our interaction with the land. And so I think that was what really resonated with people, just getting something positive and hopeful in the midst of everything else.

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