This is a salmon cannon. Its purpose is to shoot fish upriver. Really cool. But like
why? Well, because of this, dams are not great for the environment around them. Because putting a
wall up in the middle of a river tends to disrupt the ecosystem, including, of course,
the migration of salmon. So, is there something that we can do about it? Yes. And I'll give
you a hint.
Manmade dams have been around for thousands of years and some of those are still in use today. They've helped with flood control irrigation, drinking water and making electricity. Today,
hydroelectric energy creates about 16% of the world's electricity, and over 70% of the
world's renewable energy, which is great much much better than burning coal. But as more
and more dams were built to do good in the world, more and more people started to take
notice of their negative impact on the environment. When dams were initially being created. They
were really seen as modern miracles in some ways, but as dams were constructed, we often
didn't think about the impacts that were going to happen to the health of our rivers and
to our fisheries. And it really wasn't until we went through a very large dam construction
era, the 20s 30s 40s and 50s that we began to see cumulatively the impacts that dams were
having throughout California and throughout the West. When you disrupt the flow of a river,
there are so many negative consequences to the surrounding ecosystem, that it's just
hard to fit it all into one video. So trees rely on the flow to redistribute seeds. If
you lessen the flow of water, it increases the water temperature, which is terrible to
the health of plants and animals. If you hold water back by dams that water becomes toxic,
or it'll lose oxygen, both of which are not good when that water is eventually released.
Dams also stopped the flow of sediment down river, which is again, a huge problem. By capturing
water that would normally be flowing downstream. It changes the timing and the the size of
those flows. And all the fish and wildlife that live in rivers has co evolved to that
natural pattern. And a dam changes that natural pattern. So now, the system doesn't function
like it used to. And maybe the most glaring problem with dams is that it affects fish,
specifically how the fish are able to navigate their home to do something that's pretty important.
reproduce, and the poster fish for that dam damage might just be salmon. Salmon have evolved
to survive. Using this same natural pattern that rivers have with their high flows in
the winter and their low flows in the summertime. Dams have been constructed fairly low down
in a river and often end up blocking the ability of fish to move upstream and access some of
that habitat that they need to reproduce. Salmon populations have been declining for
decades, and many experts point to the installation of dams as being one of the major contributing
factors to this. So over the years, people have tried to work on solutions. If you remember
that salmon cannon that we started off with. That was just one example of something to
help the fish to upstream to spawn. There's fish ladders, fish elevators and let's see
that one more time. Fish cannons, but even though they're trying to help, it's still not the
perfect solution. So in fish ladders and elevators or cannons aren't the answer. Then what is?
A dam never lasts forever. And so you have a situation where there's no longer a need
for the dam and the cost of maintaining it is so high that it actually begins to make
sense to take that dam out and to have a lot of the ecological benefits that would come
from dam removal. Now, how do you remove a dam? It's not always explosions, even though
that is the most visually appealing, actually takes a lot of work. A lot of planning, research,
permits, surveys and just taking it down in a way that doesn't harm the environment even
more. But it does happen. It's actually happened a lot. In the US alone, over 1200 dams have
been removed and that helps restore the rivers that they were in. One of the most successful
dam removal projects that's occurred recently has been on the Elwha the removal of the dam
has opened up so much important salmon habitat. That's really helped populations to improve.
Prior to dam removal, this area we're standing in was underwater. I am from Port Angeles,
Washington, and I'm a member of the lower Elwha tribe. I grew up with the Elwha River
in my backyard. Sometimes literally, before the dams were removed occasionally the river
would flood into our backyards. So the removal of the Elwha dam began in 2011. And since
that time, the landscape has changed so much where the former reservoirs once were. So
you can see where it gets rocky that is the edge that's the water line where the lake used
to be. We now have trees growing in we have animals that have returned to the landscape.
The removal of the Elwha dam is the biggest dam removal project in history. Also one of
the biggest river rehabilitation success stories. And by restoring the vegetation. We are restoring
the habitat for other wildlife to back. And so we know that wildlife play a role in the
environment. They know that they can transport seeds and restructure the plant communities
and also alter waterflow. The first year 2014, we saw very little beaver activity. By 2016,
the beavers had discovered both lake beds and were using both habitats. They figured
it out. There were efforts for 100 years by the lower Elwha tribe to have the dams removed.
So I just find Elwha dam removal to be so inspiring and I hope that it inspires others
to protect the places that they love and call home. The Elwha River is a great success story,
and new bigger dam removal projects are already in the works. These projects are a great testament
to the communities, tribes, scientists and activists who have fought to restore these ecosystems.
But the truth is not every dam can be taken down. It's unrealistic for us to get rid of
all dams. At this point. We need dams in order to capture water that is needed for farms
and for cities. But we can manage our dams. ways where we operate them to maintain the
physical and biological processes that are so important for fishing for wildlife. Dams
can provide a lot for communities, clean water, irrigation, flood protection, energy and even
recreation. So it's unrealistic for us to remove every single dam but it is extremely
realistic to make current dams more environmentally friendly, and remove dams that aren't doing
any good. And we can use all of this knowledge to raise awareness for 1000s of proposed dam
projects.