One of my first stops after leaving the farm in Sonoma County (see the recent series: part 1 | part 2 | part 3) was at a remote location in Plumas County in the Sierra Nevada mountains for what I would call a Beaver work camp. Nikki Hill took me there to volunteer with a project run by Swift Water Design. Founded by Kevin Swift, the company implements beaver-based and process-based restoration projects to heal human-damaged watersheds.
As Kevin summarized it, watersheds in what is now the western US suffered massive deterioration through a series of events: the genocide of indigenous people and the end of their land management practices (which prevented the kinds of catastrophic wildfires we now experience); the near extinction through over-hunting of beavers (who were the original ecosystem engineers); the draining of wetlands in riparian areas (much of it encouraged by law); and relentless overgrazing by cattle and sheep (who further degraded water course structure and wiped out much original vegetation).
What we’re left with now are streams and rivers who are disconnected from their surrounding land, which has resultingly been transformed from wetlands to dry meadows and forests. Nothing against trees, but as they migrate into areas that were formerly marshy, they act like straws, drawing up the water and further depleting moisture. The water is still there, it’s just being held in a different way that is unsuitable for wetland ecology, with all the plants and animals who make their homes in such places.
There’s a lot of science behind all this and I won’t be going into the details here, but suffice it to say that we’ve studied these things enough to see much of what went wrong for such areas and some of what we could do to reverse the process. One solution is to reintroduce beavers, but short of that, we humans can imitate what beavers do, in part to kick-start the healing process, and in part to attract beavers back to the area on their own.
The day Nikki and I were there, twelve folks went to work (all employees of Swift Design except us). We split into teams and built two structures in the stream that could be called “beaver dam analogs.” This involved layering pine branches, mud and logs in very intentional ways. Swift Water Design has built built over 3100 structures on 50+ miles of streams over the last six years, so they had this down.
“Swift Water” is an ironic name for the outfit, since the whole point is to slow water down. When streams were altered to drain marshes for cattle grazing, the faster flow deepened their channels, leading to a lower water table, and shrinking the wetland area. Beavers working on a landscape slow the flow with their dams, which simultaneously creates pools for them to live in, and also raises the water table, expanding the wetland area.
Projects like this are sometimes called “beaver mimicry” and despite his experience, Kevin was the first to admit that we are poor mimics. Beavers just do it better. But it’s better than nothing, and Kevin and his crew have witnessed startling transformations in the areas where they’ve made their efforts. They revisit projects over time to monitor them and to do further work, which is a step left out of far too many restoration projects.
In the following photos, you can see the progress and completion of the analog dam I helped with over the course of just one morning.
BEFORE. This is a photo I happened to take on my morning walk before the project started, not knowing we would be working here. Note the smallish tree growing up out of the bank. This was cut down and used in the creation of the structure.
On the shore are piles of pine branches, sorted by size, from the cut-down tree and from others nearby. Geneva and Jordan are hard at work making a woven layer of branches and mud.
Cutting chunks of sod from the river bank to incorporate into the structure
Sod being collected in a sled a bit upstream from the structure. This was floated down and dumped into place.
Austin, in the foreground, cutting sod chunks. Note the rising water level.
Eventually the structure was solid enough to walk on!
The teams came together to haul this big log down and put it into place.
The new pond the next morning. The level of water below the dam is also high because the other team made another structure a little further downstream.
To help illustrate how much the water rose, the willow sapling circled here (with its base underlined to distinguish it from its reflection) was originally growing up on the bank, over a foot above the water. The stream is now much wider at this point than it was.
Another view of the beaver-mimic dam, from the side.
This project involved cutting down several trees on the edge of the meadow, and though I’m a tree-hugger, I felt fine about it. First because cutting down trees is something beavers do, and secondly because when I was there, observing how the wetland had shrunk over time, I could see that taking down these particular trees and incorporating them like this truly made sense. Jordan, who was the chainsaw operator on our team, said that she takes this task very seriously. “After all, I’m playing God,” is how she put it. Though I had only just met her, I could immediately tell that she was a very thoughtful person and that she was approaching the task with respect for the entire ecosystem. In my essay, “We All Need to be Tree-huggers Now,” I wrote: “It must be forbidden to cut down any tree at all, ever, with exceptions made only for clearly demonstrated need.” Well, this was such a case and I was grateful to be shown it.
I’ve been fascinated by the role of beavers in landscapes, and in the roles that humans can play in mimicking them, reintroducing them, and inviting them back since reading the book, “Eager: The Surprising, Secret Life of Beavers and Why They Matter” by Ben Goldfarb. This was my first hands-on experience, and I was quite inspired. Working outside in remote places with fun people greatly appeals to me and I hope my future includes more of it.
