Please tell me about fish taxi and what's a culvert
Absolutely! Allow me to set the scene:
Two salmon are swimming upstream when they smack directly into a huge concrete wall. One turns to the other and says, "Dam."
...that one definitely works better out loud, with a nice flat delivery. But it's a good starting point. Unlucky salmon are doomed to deliver the punchline to this terrible dad joke. Really lucky salmon are blessed with wild rivers with no dams at all. Medium lucky salmon have to ride the salmon cannon, navigate a fish ladder, or catch the fish taxi to get upstream. These are all fish passage solutions put in place to make up for those most intimidating barriers to migration: dams.
A quick note: I'm going to continue to focus on salmon in the Pacific Northwest, because that's what I'm familiar with. Different locations with different species of fish may have other concerns or solutions related to fish passage. But it's a big deal here because salmon have to migrate upstream to lay their eggs and continue their life cycle and everyone wants there to keep being iconic and delicious salmon around.
With that out of the way, and seeing as this post is already getting long, buckle up for the fish taxi details with a side of culverts under the cut! I promise a video and a meme to liven things up before we wrap.
Fish ladders are old news. Boring. And, frankly, expensive and challenging to design well and impossible to implement at all above a certain size.
Enter the fish taxi. The idea is as simple as it is ridiculous. Just round up your fish on the downstream side, put them in a truck with a big water tank, and drive them upstream of the dam for release. Easy peasy!
In practice there's a little more to it. Puget Sound Energy operates two dams on the Baker River. Their fish trap below the lower dam is pretty fancy, and even includes an "aquatic elevator" to raise fish up into the sorting facility. There's a whole series of gates and chutes and moveable walls that direct fish into the right holding tanks before finally being loaded into the trucks.
Not to boost corporate talking points about their mitigation strategies, but it is objectively a pretty successful site and this video shows the process well:
An extra cool thing about the Baker River fish taxi is that it also runs juveniles downstream. That may sound obvious but it's a huge improvement over old strategies like "hopefully some of them survive tumbling down the spillway or through the turbines." Ok, most dams have some form of bypass around the turbines, and the spillway is often the safer-than-it-looks intended route, but it still seems rough being a small fry. Getting rounded up in the floating collector and taking a taxi ride downstream starts to sound pretty good, all things considered.
Whew! That's the story of the fish taxi!
I'm going to try to keep culverts short (for now) because they're much less sexy. Normal people almost never think about culverts, but they cross them every day. Culverts are the pipes that carry water under roads. Although they aren't just pipes, they can be box or arch shaped structures and made of a variety of materials...but I digress! Basically any time a road crosses water that doesn't rate a bridge, there's a culvert. Some are just to drain runoff. Many driveways have a small culvert for the roadside ditch. But some are larger and allow entire streams to pass under the road. If they're sized appropriately, set at the right height to prevent a water surface drop, and not sloped too steeply, culverts can be completely passable and fish friendly! Alas, they often are not. Dams may be the largest structures that act as fish passage barriers, but culverts are by far the most numerous.
Washington Department of Fish and Wildlife inventories fish passage barriers to salmon and steelhead and estimates some 18,000-20,000 statewide. This is almost certainly on the low end. I mean, just imagine how MANY roads there are, and how MUCH water there is in Washington, a famously wet place. They intersect a lot. If you want to get a sense of the scale, there's a public facing, interactive map of WDFW-identified barriers here. Most of the points are culverts. Only the green points are fully fish passable. There are probably lots more points that haven't been surveyed at all yet. So yeah
[ID: "X, X Everywhere" Meme of Woody and Buzz from Toy Story reading "Culverts. Culverts everywhere." End ID]
Anyone who made it to the end has my gratitude and is welcome to use the very unofficial title of "Junior Fish Passage Nerd" any time they want. And if you made it here and are still interested in hearing about culverts or fish passage more generally...well, you know where to find me!
My grandma was pink-skinned,
dark-eyed, mind
like a magnet. She knew
just where to go:
all journeys lead you back home.
With that up-river faith
she leapt over obstacles
with muscle and grace
past vanishing forests
past cow-trampled banks
past claws and beaks
and the rods and lines of men.
She knew about change
as only a salmon can:
how the body in its mutability
must adapt from the wild dance of the ocean
to the narrow creek need
cell by cell, scale by scale
each step in its own time.
HUSH, she would tell me,
when my own compass needle
had spun me off with its own centrifugal force.
CELL BY CELL, SCALE BY SCALE.
LOOK FOR THE STRONGEST CURRENT.
FOLLOW THAT.
–Alexis White (1985-2014)
This is the poem, described by a dear friend, that sent me hurtling on this journey of vulnerability and radical honesty. I am looking for the strongest current. I am trying desperately to follow it.
