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
man-made 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
percent 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
in 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 stop 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 damn 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 maybe you remember
that salmon cannon that we started off
with that was just one example of
something to help the fish get upstream
to spawn there's fish ladders fish
elevators and let's see that one more
time again fish cannons
but even though they're trying to help
it's still not the perfect solution so
if fish ladders and elevators and
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 it
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 u.s alone over
1200 dams have been removed and that
helps restore the rivers that they were
impacting
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
under water
i am from port angeles washington and
i'm a member of the lower elwha column
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
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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 move back in
and so we know that wildlife
play a role in the environment we know
that they can transport seeds
and restructure the plant communities
and
also alter water flow 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 had figured it out
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there were efforts for
a hundred years by the lower iowa tribe
to have the dams removed so i just find
elwa 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
a 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 in ways where we
operate them to maintain
the physical and biological processes
that are so important for fish and for
wildlife
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dams can provide a lot for communities
clean water irrigation flood protection
clean energy and even recreation so it's
unrealistic for us to remove every
single dam out there but it is extremely
realistic to make current dams more
environmentally friendly and remove dams
that aren't doing any good at all and we
can use all of this knowledge to raise
awareness for the thousands of proposed
damn projects worldwide
if you're interested in learning more
about river health and how community
activism can bring about positive change
check out this secret indie documentary
guardians of the river about the urak
tribe's campaign to restore the klamath
river thanks for watching
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