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Imitating the Architecture of Nature

PUBLISHED: March 2, 2020

The man appeared suddenly, out of the darkness and around the bend. He was standing to the side of the asphalt, near the edge of the floodlights illuminating a barricade of orange traffic barrels and, beyond, a great pile of dirt disappearing into the night. Half of the mountain road was blocked off—was, in fact, no road at all past the barricade and the pile. I drove closer and slowed to a stop. As I did so the man made some unhurried steps toward my car. It was past midnight, late summer, in the northeast corner of California, where the Sierra Nevada peter out and the volcanic Cascade Range begins.

My car windows were down. My radio already off. There had been no other traffic, no other living thing for an hour at least, aside from the oaks giving way to pines. The choking, relentless heat of the Central Valley had loosened its grip as the altitude climbed. I was headed to a meadow called Childs, just outside of Lassen Volcanic National Park. In the meadow was something I wanted to see, a very particular type of dam—a series of dams, in fact. They were beaver dams, but they weren’t built by beavers. The technical term for these dams is beaver dam analogs (BDAs), and they were built by biologists, ecologists, and land-management experts. The previous autumn, these BDAs had been placed in a little creek named Gurnsey that winds through Childs Meadow, well before the snows filled the meadow and the spring melt flooded it. Now, I’d been told, it was a different sort of meadow—a bit marshy in spots, its soil spongy, the land undergoing a dramatic transformation back to a time before we killed off nearly every beaver on the continent. A more waterlogged time.

The man—big, bearded, a florescent-green vest over his flannel—broke into a friendly grin as he neared. “Hope you’re not in a hurry,” he said. I told him I wasn’t. He stepped back a few paces and we let the buzz of the floodlights fill the silence for a minute until a crackle came over the radio clipped to his belt. “Lemme see how long this could be,” he said, then walked back to his post at the edge of the light. I could hear him talking with a crew that must have been farther up the mountain, at another stop for traffic heading down. “Maybe fifteen, twenty minutes,” he shouted over to me. More time passed under the buzzing lights, my windows down, the man staring up the road at the big pile of dirt and whatever lay beyond. Finally, I cut my engine, and the man returned. “Not a lot of traffic on the mountain this time of night,” he said, waiting for me to explain myself, so I told him I was there to see a few beaver dams some folks had built. He looked up into the night sky for a moment, then asked me why they would do that. It was a good question, and I hoped to have an answer for him on the way back if I saw him again. People were building all kinds of crazy things on these mountains, he said. This road, for example—and he gestured toward the looming pile of earth: They were widening it, straightening it, adding more buttresses; and they’d have to do it all over again one day, when the road again started sliding down the mountain. Was it the road sliding down the mountain, or the mountain sliding down upon the road? It was, of course, both. 

Just then a car’s headlights appeared. A moment later, a truck’s, then another truck’s, and soon a whole line of vehicles—a dozen or so—rumbled by, and just as suddenly the man began waving me on past the barricade and pile, through the construction zone, up the road, up the mountain, to see yet another strange human construction, this one arguably more useful and transformative than even a road.

The people of the Haida Nation, of the northwest coast of North America, tell a story about the beaver. It begins with a young woman marrying a great hunter and traveling with him to his hunting grounds, far away from her people. They build a home, alone together in the wilderness. The woman becomes pregnant. The hunter goes away on his hunts but always returns. His hunts grow longer and longer: One night becomes two, two nights becomes a week. The woman is bored, so she takes up swimming in the pond by the cabin. Her husband is gone for ever-longer stretches, and she gets better and better at swimming and teaching her children to swim until the pond is too small for them, so she builds a dam out of branches and mud, expanding their pond. She then dams up another section of river, and another, creating a whole series of ponds. You see where this is going.

She builds a structure out in the middle of her original pond, the biggest pond, and this is where she now spends some time sleeping. Finally, her hunter-husband returns from his very long hunt. But he can’t find his wife. He searches all over until he decides she was probably eaten, and he sits down beside the big pond with the little island structure in the middle of it, and he weeps and sings a mournful tune as he remembers his wife. As he’s singing, an animal swims up to him. The animal is furry, and it carries a stick in its mouth. Behind the creature are two more, smaller, also swimming, also carrying sticks in their mouths and chewing on them. The biggest of the three speaks to the man. “Do not be sad,” the animal says. “It is I, your wife, and your two children. We have returned to our home in the water.”

I first encountered the Haida’s beaver tale in the book Beaver by Rachel Poliquin. “The legend gives voice to all that is captivatingly human and implausibly true about beavers,” Poliquin writes. Beavers are familiar, knowable, and domestic. They build homes—lodges—for their families. And they are, apparently, companionable. Fur trappers sometimes kept orphaned baby beavers as pets after murdering their mothers. The conservationist Grey Owl described baby beavers as “small and willing captives, with their almost childlike intimacies and murmurings of affection, their rollicking good fellowship with not only each other but ourselves .… They seemed to be almost like little folk from some other planet, whose language we could not yet quite understand.” 

Perhaps the people building beaver structures were closer to an understanding of the little folk’s language. The next morning, after my drive up the mountain, at the Mineral Lodge Restaurant, I met Kristen Wilson, an ecologist at the Nature Conservancy and one of the overseers of the BDA project. Soon we’d be heading out to Child’s Meadow to see the beaver dams she was looking after. Over breakfast, she outlined the broader implications of the project. What I had to understand, Wilson said, was that something seemingly as simple as a small dam constructed out of woven willow branches, blocking up a thin creek, was not quite so simple. The dam was meant to perform several tasks. A few of these, such as habitat restoration and water retention, were fairly obvious. But one of the most important things the dam would be doing was trapping carbon in the murky, silty, slow river bottom behind it. 1 This task—carbon capture—was what paid for the dam’s existence. The BDA pilot project in Child’s Meadow had received the bulk of its funding via California’s cap-and-trade program, which in 2018 paid out $1.4 billion to fund a huge range of projects, everything from rebates for buying environmentally friendly cars and buses, or for solar panels, to grants for planting trees in urban areas, to simply buying up land to preserve and restore it.

The BDAs were, Wilson explained, a newer and cheaper form of meadow restoration. The usual process of restoring a wetland in a meadow was simple construction: dig a pond, plug up the downstream end, watch the water fill it in. Pond-and-plug, it’s called. Of course, this requires some big machinery, but using big machines—engineering our environment—is something we are good at, and it results in a picture-perfect mountain meadow with a pond at its center. One problem with pond-and-plug is that it is expensive, easily four or five times the cost of BDAs, if not more. The bigger problem is that it in no way replicates any natural process. Backhoes, it turns out, don’t have an ecological equivalent. So, while the pond in the meadow looks picturesque for a season or two, after four or five years the river has usually broken through or, worse, silted up so badly behind a concrete dam that the pond is no longer a living system. BDAs, by comparison, create “natural alluvial plains,” Wilson said. “They trap silt but don’t lock it up like a human-built dam. The silt sifts down, the amount changes with the seasons and rainfall, distributing a healthy but different amount of sediment throughout a region. It manages the soil, the water, the whole ecosystem.”

Wilson is obsessed with rivers. She has studied them for years—photographing them, giving presentations about them, sitting silently next to them and just watching and listening to them move. And rivers, even little creeks, even arroyos that are dry most of the year, do move constantly, jumping banks, altering course, cutting new paths. We have this idea of how a river meanders, that perfect, serpentine turn. “Why are we restoring our streams to the same line of beauty?” Wilson asked me. She handed me a napkin and asked me to draw out what a river should look like, and sure enough I drew a line, a repeating S. She looked at my drawing. “When you look at real rivers, not the textbooks, it’s not symmetrical. The bends are never perfect because nature is messy.”

The server came by to drop off the check. “It was eighteen dollars even,” she said. “That’s good luck. Y’all should buy a lotto ticket.” 

Wilson, still staring at my meander drawing, finished her thought. “What you’ll see, out in the meadow, isn’t going to look like the ideal vision of a mountain meadow. It’s chaotic. But it needs to be that way. In the chaos is opportunity.”

To reach the chaos, we had to squirm carefully under a barbed-wire fence, then take a long walk across the open plain of the browned meadow, until the creek revealed itself. On the walk out, we’d seen what appeared to be a Cooper’s hawk in the distance, and Wilson stopped. When she’d been out in the meadow the day before, she’d watched a pair of sandhill cranes defend their young from a golden eagle, and she worried over the cranes. She wanted to make sure the eagle hadn’t returned. Once she’d confirmed the hawk was a hawk, and that it wasn’t near where the cranes were nesting, we pressed on. The ground grew muddy long before we reached the overgrown creek bank, and by then my shoes were soaked, so we plunged in and trudged through the water until we reached the first BDA.

It looked like something humans had built. The willow reeds were too nicely woven into a thick mesh between tall, straight, deeply sunk wood pilings that anchored the dam. But, in places, the wild had won out: Bits of the dam were listing and, here and there, the water was pouring over the woven willow’s top. The creek, soon after the snowmelt, had swelled and pummeled the structure, plugging up parts with detritus, and opening up others. Though the dam was still there, the creek wasn’t fully stopped up, just slowed in places. Wilson was delighted by this outcome. The structural failures were natural successes. The creek pooled behind the dam while also spilling over and around it: pouring, churning, stirring, reshaping, tilling—renewing the land itself. An environment shaped by beavers is often described as dynamic, and you could actually hear it in the water’s trickles, splooshes, and silence—a symphonic waterway. 

Farther down the creek was a strand of dead trees. I asked Wilson what was going on down there and she told me that’s where the real chaos was, because a family of beavers lived there. We walked down toward the dead trees and, as we neared, Wilson and I spotted a woman hunched over a section of creek bank, staring intently at the water. The creek here was indeed chaotic. The beavers had dug channels, as they do, to avoid awkward passage over land. The waterways cleaved the landscape into jigsaw-puzzle pieces. It was easier just to stick to the waterways, rather than chance it on land and trip into an unseen channel.

The woman, Wilson whispered to me, was Karen Pope, a wildlife biologist who studies frogs. Specifically, the Cascades frog, a very endangered species that lives precisely within the beaver-induced chaos. We watched her watching the river, hunting for a frog, until she stood up, noticed us, and beckoned us over. She and Wilson immediately got down to it. Wilson wanted to know what Pope thought about the sections of dam that had blown out, where the water was coming over and the dam was no longer doing what we think a dam is supposed to do. Pope pointed downriver slightly from one such damaged section, to where a small bite had formed from the flow of water hitting the bank and scooping away at its side, creating a still little pool. “That’s where the frogs breed, right there,” Pope said. “And here—in these little channels the beavers create, that’s perfect frog habitat too. This frog is tied completely to this environment.”

There were many such species. A bird called the willow flycatcher, also endangered, hunts in the beavers’ ponds and nests in the beavers’ willows. There were insects and muskrats, fish and waterfowl, and anything that needs an excess of water in an often dry landscape. It struck me then, as Wilson described species after species that benefits from beaver engineering, that the lesson of the human-built beaver dams, and of being more beaver-like generally, was one of deconstruction. That is, instead of our built landscape existing as a way to live apart from nature, of keeping it at our doorstep, we should accept the fact that nature is inescapable. The whole climate is changing, and large swaths of the globe are becoming inimical to human life. Nature is a problem we can’t engineer our way out of. But, like the beavers, we might engineer our way back into it.

I spent another day in the meadow beside the threaded, chaotic creek. I was hoping to drive back down from the mountains the way I came up, but a wildfire broke out near that road, so the route was closed off. I took a different way down and missed the bearded man. As I again neared California’s Central Valley, the sky began to darken with a hazy layer of smoke. Wildfires were breaking out all over the state that late summer. It happened again the next summer. My aunt and uncle’s house burned down. My parents’ home very nearly burned down. Then a hard fast rain came and the charred sides of the mountain behind their house, my childhood home, liquefied and plowed through the old neighborhood, killing many neighbors.

The landscape of the beaver is “a patchwork quilt that is constantly being picked apart and reassembled in new patterns,” Frances Backhouse writes in her beaver history Once They Were Hats. In the past, nearly one out of every ten acres from Maine to California was beaver wetland of one form or another. You can still see the quilt’s shadow, if you squint just right. The shape of the river valleys throughout the Catskills is the work of as much as twenty-five thousand years of beaver habitation. The mountain meadows throughout the whole of the West, including the Sierra Nevada, were sculpted by and filled with beaver ponds. Arroyos weaving through New Mexico were, three hundred years ago, damp and dammed and home to beaver too. Outside the slave trade, the trade in beaver pelts was the foundation for much of the American economy. It would have remained that way if we hadn’t been so good at hunting beaver. By 1775, they were no longer in any of the thirteen colonies; not a century later, they were nearly gone from all of North America. We hunted them so successfully that the species turned nocturnal.

The whole of nature—which is to say, all of the world—is like the beaver’s patchwork quilt: dynamic, changing, chaotic. Beaver dam analogs and their champions often find themselves in uneasy coexistence with regulatory agencies responsible for keeping rivers manageable and controlled. The very purpose of a BDA is to add a bit less control—a bit of untidiness—to the river. The dams help the river burst its banks, begin to meander, and reenter the old floodplains. But then, it’s often a flood-control agency rubber-stamping such projects, and these agencies are inherently skeptical of introducing an object meant to bring about the very thing—a flood—they have been tasked with preventing.

“People are really attached to stasis. It’s the unfortunate result of human nature,” is how Kate Lundquist explained the resistance to BDAs. Lundquist is a director at the Water Institute at the Occidental Arts & Ecology Center in Sonoma, California. She and her colleague Brock Dolman describe themselves as being part of “the whole beaver dam analog movement,” which is also a movement toward what’s known as process-based restoration. The idea behind process based restoration is both simple and radical. Rather than reconstructing an ecosystem based on our ideas of how that ecosystem appears, to us, why not try to kickstart some of the primary drivers of that ecosystem and let nature take it from there? Often, those drivers appear from the outside to be very destructive. But that’s also the point. That which is destructive acts as a disturbance mechanism, churning the landscape and creating new opportunity. Beaver dams, of course, are a crucial disturbance mechanism for wetlands. Throughout the West, fire is another.

“Disturbances often disturb people,” Brock Dolman said. “The irony is that fundamentally, disturbances are the driver of evolution in every ecosystem. They’re regenerative. Humans, however, are the opposite. We clear-cut the forest or plow the prairie. We nuke biodiversity and pave it all over. We impose upon, rather than compose with. We’re degenerative, not regenerative, disturbers.”

Dolman mentioned a place where the kind of regenerative disturbance and process-based restoration he and Lundquist were talking about had accomplished some extraordinary transformations in a very short amount of time. About three years earlier, some BDAs had been placed in a small creek outside of Lincoln, California, just north of Sacramento. It was hot, dry, brush-filled rangeland that had, a long time ago, been marshy floodplain pockmarked with beaver ponds. Gold miners came in, dynamited the creek, and named it Doty Ravine. It had been tamed ever since. But in just a few years, Dolman said, “a very large chunk of land has been turned back into an insane beaver habitat.” The place was, he told me, like going back in time to a prehistoric, practically prehuman landscape. 

Damion Ciotti is a rangy man who speaks with the quiet enthusiasm of someone prone to spending long bouts outside the office whenever possible. Ciotti was driving a pickup through winding roads in the Sierra foothills, out toward Doty, while telling me about his early experiences in hydrology, when he really began learning a river. Ciotti is a restoration specialist at US Fish and Wildlife and is the reason there are BDAs in Doty. When he was in graduate school in Oregon, and becoming obsessed with fly-fishing, he’d skip class and hit the river, watching it very closely for hours—all day, more or less. That’s where he learned how to watch moving water.

“So I’m observing the river like, I’m really trying to find fish: When are they going to be here, in these tailwaters? How does the food float to them? I’m watching the river during different flood stages, seeing how the fish might react to peak flows, learning how they start to move back upriver once the flow begins to subside. It’s when I started to see it like a fish that I started to really learn the river, seeing it as a system at different stages, knowing its power. It’s not like just going out to measure what’s going on. You’re thinking about the fish, relative to what’s going on. You’re not just a scientist collecting specific data. You’re taking in a bigger picture.” There were certain pools, certain rocks in certain pools, where he just knew that steelhead would be resting, waiting for a high-river flow to slack so they could continue their run upriver.

He nodded at a thicket off the road, a little stream enfolded by tall grasses and willows. “Historically they were all connected down here, all these streams. But now there’s just a bunch of canals.” As we drove on, the landscape opened before us, still rolling but punctuated by grand valley oaks and a savannah of browned-up bushy sedges. Ciotti mentioned he’d found a salmon carcass at Doty last year, and how miraculous it was that the anadromous creature had made it that far up the waterway despite all that stood in its path. He hoped it had somehow managed to spawn, as the new wetlands made for perfect salmon hatcheries. Salmon, frogs, birds, and a seed bank for native aquatic plants—the beaver-built wetlands were nutrient-rich nurseries for all sorts of critters. And the cows, even though they didn’t have much to graze, seemed to enjoy hanging out near the water’s edge too. It certainly was cooler down there in the summertime.

We reached a locked fence by the side of the road and Ciotti pulled up to it, jumped out, unlocked it, and drove us onto the rangeland property. In the distance stood a strand of cottonwoods. This was where the wetlands began. Ciotti parked on a bluff above the strand and we quietly put on waders to trudge through the sludgy muck. In the silence, I noticed the air was alive with birdsong, coming from the cottonwoods, willows, rushes, still waters, a ringing that emanated from this oasis. We dropped down into it and the birdsong grew near cacophonous.

We spent a few hours navigating the wetland transformation at Doty. The going was slow, not just on account of the felled trees and thick brush but also because, often, we simply stopped in the middle of the waters in hushed and reverent amazement. Ciotti was usually far ahead—a more adept wetland wanderer than I—and I often saw him standing still, staring at a spot in the water, a bend in the bank, lost in thought.

At one point we came upon a huge earthen ridge running roughly perpendicular to the stream’s path. I wondered aloud what could have caused this, if it might be some remnant of the miner’s dynamiting. “We didn’t build this—it’s a beaver dam,” Ciotti said. It was covered in vegetation, much of it sprouting. I saw, suddenly, that it outlined a huge pond. Ciotti said it was at least five, maybe ten acres. “Their lodge is somewhere out in the middle.” I couldn’t quite wrap my mind around the size of the dam, or the pond. Ciotti made his way over to me and tried to explain what had happened to make this all possible. He pointed to the dry highlands back behind us. “Before this, we had that single-thread channel, going along the edge there. We first put a BDA in that channel. And we started reinforcing the beavers’ dams and convinced the land trust to leave the beaver be. By the first winter, we’d reactivated the flood plain.” By which he meant the BDA had caused the stream to back up and spill its banks, bringing water to where it had been long ago. “Then the beaver came in and dammed it all up. They took over.

“People think you have to do so much more than you have to do—fill these old channels in, dig out ponds, reinforce banks. All you need to do is get one zone, one spot, and it all grows back in.” The BDA had cost something like $2,000 all told, for Ciotti’s time and others’ as well as upkeep. There’d been another pilot project for a wetland in the same area, only about a quarter of an acre, which had cost $125,000 using the usual intensive management and overengineering. Now, with just this single, small, destructive catalyst, they had sixty acres of pristine wetland. I asked Ciotti what had been the biggest surprise about the whole project, expecting him to say something about the extraordinarily low cost.

“It’s the beavers, they did something so monumental. This, all this, was oak savannah. Now, in three years, this is the largest connected wetland in the whole Sierra foothills. These aren’t especially big creatures, they’re not burning a crazy amount of calories, and just look at all this!” He pointed to the strand of young cottonwoods, and the willows coming in along the bank. As if on cue, a flock of ducks noisily flew in, quacking and flapping and splashing down in the pond. I started to say something about the busyness of beavers, but I stopped myself. The trouble with language and its anthropomorphism is that it is blinding. It robs us of the ability to see the animal for what it is, which is ultimately unknowable to us. Instead, its otherness is replaced by what we think we know about our own experience of the world. Jenny Diski once wrote on “the colonising aspect of finding easy connection with animals, while at the same time aching for it and identifying it in my relations with animals. The balance of the affect is always ‘They are somewhat like me,’ rather than ‘I am somewhat like them.’”

As we stood there beside the pond, I instead recalled how I’d once read that a beaver won’t build a dam if it doesn’t have to. If, for example, the water running through the patch of river where it would like to make its lodge is wide and slow, or if a natural pond or lake is already to its liking, a beaver will simply use the water as it is. Or, more often, a beaver will patch up a broken dam it has stumbled upon—in this case, at Doty, those BDAs. A beaver, you could say, will do exactly as much or as little work as is required to shape its environment. One might even go so far as to say that beavers are especially like humans in this particular attitude—lazy, if allowed to be; industrious, if necessary. But no, of course, they aren’t like us at all. Or at least not as much like us as we’d like to believe.

I thought, then, of the final words from the woman-turned-beaver in the Haida legend: “We have returned to our home in the water.” The story seems to be less about how beavers are like us, and more about how we might become like them. 

1 That, and another, even more crucial element: a fence. Wilson and her colleagues found that 14 percent of the increased greenhouse-gas storage was attributable directly to beaver dam analogs and their hydrologic impact, while the vast majority—86 percent—was due to the new fence that prevented cattle from grazing near the stream. No cattle meant far more plant productivity and growth.


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