Hakai Magazine

Temporary waterways are integral to ecosystems around the world. Photo by Tim McGuire/Corbis
Temporary waterways are integral to ecosystems around the world. Photo by Tim McGuire/Corbis

Embracing the Weirdness of Waterless Waterways

The drought in California has created an obsession with water, but sometimes, no water is just fine.

Authored by

by Jude Isabella

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There’s a drug deal going down within earshot as my colleague and I sip coffee outside a bar in a small coastal Californian town. The deal is not unexpected, given the vibe here. The duo exchanges goods and cash and moves on. Then a woman in her mid-30s exits the bar, pauses on the sidewalk, and yells, “Where’s my fucking vacuum?” That was unexpected.

We’re sitting outside Smiley’s Schooner Saloon in Bolinas, a town in Marin County that’s less than 30 kilometers northwest of San Francisco. The saloon is the town’s centerpiece. The weather-beaten curio of a building is a testament to how different Bolinas is from other places in Marin, a county that was once hippie central and is now gentrified, commodified, and homogenized, from the Toyota Priuses that clog the freeways to the universality of espresso. Bolinas seems like the only town in California where Philip K. Dick—the late Marin-based writer known for his paranoid delusions and prescient fiction that inspired movies like Minority Report and Blade Runner—might still find room for his weird ramblings.

The saloon, the only place open serving coffee at 2 p.m., smells funky. Two drip coffees cost just a few bucks. It’s February, not really tourist season, and tourists are usually brushed off in Bolinas anyway. We stopped here because we’re lost.

We’re looking for a trail that leads to Pine Gulch Creek to meet with Michael Bogan, post-doctoral researcher at the University of California, Berkeley. Before stomping outside, the woman looking for the vacuum had given us directions to the trail.

“Where is my fucking vacuum?” she cries again. Do we look at her? Ignore her?

“It’s a vacuum, in a box, that I’m going to return. Who would do that?”

Our short stay in Bolinas turns out to be the cultural highlight of a two-week stay in California. The reason is clear: the town lacks the bland uniformity of the rest of the region. And it’s not just us who think so—the residents know so. When the owners put Smiley’s up for sale last year, an online article about the saloon caught people’s attention with the tag line Help Keep Bolinas Weird And Buy This Legendary Bar. Residents regularly rebuff the developers and realtors who sniff around the offbeat town and ogle the multimillion-dollar potential of Smiley’s and the quaint street it dominates. Part of Bolinas’s beauty, however, is its lack of—and desire for—perfection. Or someone else’s idea of perfection. It is perfect in its imperfections; what the Japanese would call wabi-sabi. But this is not a story about Bolinas; it’s a story about diversity and how important it is to value weirdness, differences, or the unexpected.

After leaving Smiley’s, we meet the lanky, 38-year-old biologist at the Pine Gulch Creek trailhead. Bogan, his short, dark hair speckled with gray, sports the outdoorsy attire of most field biologists—hiking boots, backpack, quick-dry pants, visor. He pauses to gather his thoughts before answering a question, is quick to smile, and is happy to share his knowledge of the natural world. Bogan also likes the offbeat and the unexpected, which is apparent in his choice of research: intermittent streams. As important as a flowing stream is, its opposite—a dry stream bed studded with stagnant pools—is just as vital. People tend to think of flowing, perennial streams as the normal state. But streams, particularly in drought-prone California, are more often intermittent, dynamic habitats that alternate between extreme conditions: wet and dry, movement and stillness. And, counterintuitively, in terms of biological diversity, it’s the temporary waterways where the future may lie, where the unusual, the unique, the unexpected life forms flourish. As the climate changes, studying them, conserving them, and valuing them in their de facto state—as ephemeral and dynamic—is more important than ever. Intermittent streams are the Bolinases of California waterways.

About half an hour later, we’re hiking along the trail toward Bolinas Lagoon, passing a birder in hot pursuit of a black vulture, a surprising arrival in Marin County when it was first spotted a couple of weeks ago. The bird is so rare that—at this moment in time—there have been only nine previous sightings in California, and the Marin observation is a first for the county. The species seems to be expanding north, likely in response to climate change.

Another surprise at the lagoon, Bogan tells us, is the coho salmon. After a 30-year absence, the migratory fish made a splashy reappearance in 2001. “That got the biologists pretty excited,” Bogan says. The fish probably came from another river system, probably straying in their search for a suitable spot to spawn.

As we talk and walk, the sound of the creek grows louder. Pine Gulch Creek is very wet. And running high.

Michael Bogan studies intermittent streams at Henry W. Coe State Park in California. Photo by Jude Isabella

“This flow is from the past three days,” Bogan says. It rained a week earlier, but this part of the creek, which flows into the lagoon and on to the Pacific Ocean, rarely dries up completely. A number of tributaries empty into the creek, and about 30 percent of them go dry for long periods.

The creek is one of Bogan’s three study sites, which together represent a wet-to-dry gradient. This Marin County site is relatively wet. The second site, in Henry W. Coe State Park, about 50 kilometers south of San Jose, is relatively dry. The third—the farthest south, about 300 kilometers away in Pinnacles National Park—is the driest of all.

At each site, Bogan records water flow, measures abundance, and identifies fish, amphibian, reptile, and insect species. With their different water regimes, the three sites should feature different insect species. In cool water with lots of oxygen, Bogan will find mayflies, caddisflies, and stoneflies hugging the bottom of a stream, hooking their tiny claws into debris, rocks, and sediments. In standing pools—refugia—separated by sections of dry stream bed, he’ll find beetles, giant water bugs, and other species capable of surviving in both running and stagnant water.

“Essentially, these refugia become more important in times of drought—it’s the only place some species can survive during the dry season,” he says, pointing out that, with worse droughts on the horizon, species that tolerate a parched habitat might have an advantage when it comes to survival. “It’s a harsh environment, so you might see some novel adaptation, and that adaptation could become really important.”

It’s basic evolutionary theory, but it’s not an idea that California legislators ever considered as people crowded into the state over the course of the 20th century.

Raphael Mazor, a biologist with the Southern California Coastal Water Research Project, focuses on identifying and assessing intermittent streams in southern California. He describes our knowledge of these episodic waterways as fuzzy at best: “We’re getting a picture.”

Overall, Mazor says, California is pretty arid, though its environment is complex, ranging between very wet and very dry regions. The state has focused on managing larger, perennial streams and rivers, perhaps working from the assumption that they are the only ones with an ecological function. But that’s not true, says Mazor. Aside from the pools, where aquatic life—free of invasive competitors—survives, the dry riverbed itself may serve as a barrier against invasive species. Take the New Zealand mud snail, for example. This invasive snail, which is found in many Californian waterbodies, including Los Angeles’s Malibu Creek, can completely cover a stream bed, reaching densities so high that they represent 95 percent of the biomass in a stream. Such a blanket of snails crowds out native invertebrates, disrupting the food chain. But the tributaries of Malibu Creek that run dry have no mud snails. These waterless riverbeds form lines of defense that help protect the larger ecosystem from an invasive species.

And Mazor points to another major water problem in California, one that is largely unknown outside of the scientific community: water flowing continuously where it’s not supposed to.

“In southern California, our urbanized areas are extensively perennialized,” Mazor says. Dams, groundwater pumping, and development in general have disrupted the natural ebb and flow of water in many areas. Yet to exist in a dry condition is typical for California streams and rivers, much like it is in other dry regions of the world, where riverbeds are more often accepted for their here today, gone tomorrow character. “The way we divide up the world is not the way biology divides up the world, and we need to be thinking about that,” Mazor says.

Farther upstream from where Pine Gulch Creek empties into Bolinas Lagoon, we head to Bogan’s monitoring site, hiking a kilometer uphill along a sunny, open trail—skirting cow patties and swatting at the chorus of flies and bees serenading us—until we cross into a giant faerie glen where oaks and redwoods shade a path. Sunlight streaks through gaps in the tree canopy and water trips over rocks and half-submerged branches, drowning out the sounds of our footsteps.

Bogan sets up his laptop next to the running stream. He wades through the water to retrieve a sensor from its waterproof case and then plugs the little device into his computer. A graph with jagged lines pops up on the screen, showing the stream flow over the past couple of months. The stream bed was completely dry from New Year’s Eve, when Bogan set the sensor, until two days before our visit when a hard rain broke a six-week drought.

The scientist gets to work. He swaps out a battery and drops the sensor back into the case. Then he strings a tape measure along the creek for 30 meters and proceeds to dip his net into the stream every three meters, searching for life. He’s looking for a vital and huge base of the food web: insect nymphs, larvae, and other invertebrates, a lattice of edible gems that support amphibians and fish.

When streams flow, dobsonfly larvae are often the top invertebrate predators. Photo by Michael Bogan

Appropriately for a faerie glen, we find the closest thing to a dragon in this ecosystem, a California giant salamander. But this one, Bogan notes, as he snaps a photo with his smartphone, is little—about a quarter of the size of a full-grown salamander, which can be 30 centimeters long. “These guys really seem to like these intermittent headwater sites,” he says.

Some fish, including coho salmon, also prefer these sites. Coho—endangered in central California—depend on headwater areas where sporadic streams are common. Coho remain in fresh water for about a year in California. Within the salmonid family, coho have their own idiosyncrasies, one being this preference for headwater streams, places that fisheries scientists call “low-velocity refugia,” where there is less water, along with slower flows and lots of nymphs and larvae to gobble. Streams that experience a whoosh of winter floods and high-speed flows are unfriendly habitats for coho. The tumultuous conditions can fatally injure fry as they emerge from their eggs in spring. In contrast, a low-velocity refuge is like a womb, a protected place where smolts can grow to an optimum size before tackling the big, bad ocean. This habitat preference makes intermittent streams vital to some coho populations. In one well-cited study, coho hatched in intermittent streams that feed into a mainstem river tended to be bigger and out-survive their mainstem brethren. And they did just as well as, or better than, the coho from perennial tributaries. In fact, biologists have noted that under particularly dry conditions, coho that overwinter in waterways with intermittent flows are larger than those from perennial streams.

Intermittent streams pose an obvious challenge to fish: fish need water. Yet a stream that goes partly dry has a role in fish ecology, as weird as that seems—we just failed to realize it until fairly recently. The life cycle quirks of animals like coho, with its preference for tenuous streams, are probably adaptive; weirdness translates into resilience and becomes an evolutionary strategy.

While stream refugia are starting to get the attention they deserve, the dry stretches separating aquatic islands and the fully dry stream beds get almost no respect. They’re overlooked resources and are even more mysterious to science than intermittent streams. Alisha Steward, an adjunct ecologist at Griffith University in Australia, studies dry riverbeds. Australia has many of these, and scientists are only now grappling with the idea that river channels, when dry, offer habitats for animals. But not any parched river will do. “A good-quality dry riverbed needs a good-quality river before it dries up,” Steward explains. She studies invertebrates, including beetles, ants, and spiders, that frequent dry riverbeds. A waterless riverbed is a variable habitat itself, its earthiness a gradient of coarse to fine material, which can also act as a shield for any water stored below.

The most visible users of desiccated streams and rivers are the big animals, including humans, who have traveled them for millennia. In the biblical Book of Exodus, Moses and his followers hiked along the wadis of the Negev desert. And in Kenya, Samburu herders often coax their cattle and camels along luggahs, which are natural, easily traversed paths—until flooded by seasonal rains.

In coastal California, even as modern humans control water’s flow and hold it captive with dams, other mammals still appreciate a good, dry stream as a travel corridor and a source of food. Raccoons, skunks, gulls, and shorebirds, for instance, feed on exposed freshwater mussels as the water levels drop in some watersheds.

In the United States, excluding Alaska, 59 percent of streams are intermittent or ephemeral, a number that rises to 66 percent in California and 94 percent in Arizona. But common as it is for most streams to go dry, in the current climate—at least in California—they’re going dry earlier and staying that way longer, lending an urgency to the study of these historically overlooked ecosystems.

A couple of days after the hike up Pine Gulch Creek, at dawn, we climb into Bogan’s little red Toyota pickup truck. We’re on our way to Henry W. Coe State Park in the Coyote Creek watershed, roughly 60 kilometers from the Pacific Ocean. It’s the site that’s drier than his Pine Gulch Creek study site and wetter than the one in Pinnacles National Park.

As we crawl through Silicon Valley, the morning traffic breeds in front of us. One car seems to beget two more, two cars beget four more, and the little red pickup is soon an anomaly in a sea of silver, gray, and champagne-colored sedans and SUVs, many of them hybrids. In the land that gave the world instant communication, it seems odd that the culture tolerates such a plodding pace of travel.

Bogan, however, is upbeat. It’s a perfect day to collect stoneflies; they emerge just after the rains. The day is hot, so it’s a relief when we turn onto a narrow, two-lane road that winds through a woodland—a patchwork quilt of gray pines, madrones, California laurel, and about half a dozen varieties of oak. Varied thrush flit overhead on their northward journey, yellow-billed magpies and sparrows cavort in the trees, and in a field, a solitary mule deer nibbles some greens. Bogan parks the pickup and gathers his gear. We spend the next 20 minutes or so trudging up and down a dirt road, with the biologist periodically exclaiming his surprise at the abundance of water pouring down streams that were completely dry just six weeks ago. He shows us sycamore trees lining the banks of one stream. A sycamore’s deep roots—perfect for sipping moisture from a shifting water table—need air circulation. Perennial streams suffocate sycamores. “So their presence indicates that this is an intermittent stream,” Bogan explains. Dry summers are not normally a problem for sycamores, things of beauty that offer us relief from the scorching sun.

We pause a few times, looking for stoneflies in the stream. One of the reasons Bogan is quantifying and identifying the life of intermittent streams has to do with legislation and the way the US government interprets its laws.

A 2006 court case argued before the Supreme Court led to a judicial rift over what constituted “water” under the country’s Clean Water Act, legislation adopted in 1972 to strengthen the protection of American waterways. (Among other things, the act prevents developers from prepping development sites, often for malls or condos, by dumping fill into wetlands or streams.) In the court case, four of the justices backed a broad definition of water that included intermittent streams. But another four argued that “water” means relatively permanent, standing, or continuously flowing water: streams, oceans, rivers, and lakes. (One justice took a position different from the other eight.) The new interpretation (water as a permanent feature) puts streams that don’t quite fit the judicial definition of normal—all water, all the time—at risk.

The case alarmed scientists, including Margaret Palmer, a professor at the University of Maryland Center for Environmental Science. Palmer was galvanized to dig deeper into the ecological value of intermittent streams that same year, after she appeared as an expert scientific witness in another federal court case questioning the worthiness of these irregular ecosystems.

Palmer, co-author of the 2014 Science paper, “Why Should We Care About Temporary Waterways?” has spent much of her career researching the ecological effectiveness of restoring streams and wetlands. For the past several years, however, most of her work has focused on studying how intermittent and perennial streams transport and process different elements, such as carbon and nitrogen, that are essential to life.

Of course, temporary waterways vary from region to region, from environment to environment: waterways in California are unlike those in Maryland. And scientifically, the source of the water varies too, defining two different kinds of temporary waterways: intermittent streams flow part of the year and are fed by groundwater and rain; ephemeral channels are fed by rain or snowmelt. “If we obliterated [temporary waterways], we would obliterate [many] rivers worldwide,” Palmer says.

On August 28, 2015, a new Clean Water Rule came into effect, partly as a result of the 2006 Supreme Court case. It clarifies the definition of “waters of the United States” to include some intermittent streams (though this is contentious and faces further legal challenges), but not all of them. Left unprotected, these elusive waterways face another threat. Palmer points to a legislative trend that could doom these eccentric waterways: many politicians dealing with the complexities of environmental mitigation now favor giving up one ecosystem for development in return for ecological restoration elsewhere. Allowing the destruction of an intermittent channel for a promise of restoration elsewhere, usually some part of a perennial stream, is dangerous, Palmer says. “Ecologically [these two types of streams] serve much different functions.” The trend is spreading: Japan, European countries, and Australia are also considering adopting a mitigation process that allows an ecosystem swap. “That’s where my concern is right now,” Palmer adds. “You can’t trade one for the other.” Nor do restored streams function nearly as well, ecologically, as a stream—temporary or perennial—that was never lost in the first place.

Bogan nets different species of insects from a stream, dropping them into a plastic pan full of water. They wiggle, twitch, and then abruptly cease all movement, allowing the mini current in the pan to carry them to a new location. Then, just as suddenly, they flip back into a frantic, horizontal dance. They’re like the unconventionals at the prom—the first to the dance floor, the ones who get the party started.

Stonefly nymphs are an important part of the food web, and a valuable meal for various fish species. Photo by Michael Bogan

Any angler would recognize the brown and black nymphs careening around the pan—the nymph is the immature life stage of the five or six stonefly species that inhabit this stream, dry or wet. They haven’t changed much in 250 million years: stonefly nymphs have stout bodies, six crab-like legs, and slender antennae mirrored at the posterior by two tails. The nymphs in the pan are about as long as a fingernail.

Bogan also points out the larva of the dobsonfly, as it seems to terrorize a nymph in the pan. Vaguely caterpillar-ish with over 20 appendages and small antennae—it could easily stand in for the hookah-smoking caterpillar in Alice in Wonderland—the dobsonfly is also popular with anglers as fish bait. The creature we watch probably emerged last year and will live up to six years, taking advantage of the 12 weeks or so of annual stream flow to feed and grow before burrowing into the stream bed when the water disappears. During this hiatus, its body shrivels, only to bounce back to life when the water returns.

One species Bogan hopes to find is the Saratoga stonefly, first described in 1987 from four specimens collected around the San Jose area. Bogan unexpectedly found one a few weeks before our visit, and it’s these rarely seen, poorly understood species that especially interest the scientist. But the Saratoga stonefly eludes us today. “It may turn out that we think they’re rare, but they’re actually common, they just occur in these habitat types that we don’t normally look at,” Bogan says.

By studying temporary waterways, Bogan and his colleagues discover their inherent value, rather than focusing on the value they’d have if the waterways were more permanent, or were “improved” in some way. As in the case of Bolinas, all some people see is an imperfect place that needs improvement. But it’s perfect already.

It’s striking how we judge communities outside the mainstream, how our gaze misses what they offer, misses the nuances and the strengths that come with pools of odd specimens, misses their value as places that allow the weird to thrive. Shouldn’t there always be room for the unexpected: for a Saratoga stonefly, and a rundown saloon, an outraged woman, and a wayward vacuum cleaner?