Before I built a wall I’d ask to know
What I was walling in or walling out,
And to whom I was like to give offense.
- Robert Frost, “Mending Wall”
§ In San Diego County the landscape softens. The mountains are less towering, the valleys less yawning, the contrast between urban and wild less shrill. Ownership is dappled; ranches and farms still spread over the higher plateau. Oak savannas and soft chaparral mingle with hard brush and granite boulders that appear to graze on the land like sheep. Orchards and parks daub the peri-urban scene. But as the urban pockets jell and add layers like a concreting nodule, the borders become more rigid, and a creeping suburban pastoralism hardens into a fractal frontier with little to buffer the once-rural from the fast-urbanizing.
This kind of geography frustrates management, if you think of management as the application of explicit principles to distinctly bounded lands. They echo Robert Frost’s famous dictum, Good fences make good neighbors. As landscape geometry, however, San Diego belongs more with Schrödinger’s cat than Euclid’s Elements; administratively, it requires a conceptual leap, like moving from Newton’s laws to quantum mechanics. The world tends to seep between those borders, to replace the exactitude of a drawn digital world with the sloppy analogue of the real one. Moreover, borderlands are notorious as places in themselves, not simply a swirl of what fronts them. As Frost also noted, Something there is that doesn’t love a wall. That wisdom – both sides of it – applies to fire. And it manifests itself, with paroxysms of violence, in Southern California.[i]
Certainly fires both respect and ignore walls. The essence of fire suppression is to erect one, called a fireline; and the goal of presuppression, to create a fireline in advance, called a fuelbreak. Yet vigorous fires frequently leap over them. Some walls are both necessary, and when most needed, frequently useless. In this regard they reflect the most fundamental of conundrums in fire management, how to cope with the big fire, the rare but catastrophic event. But they also exhibit, in miniature, the dilemma of fire in the Southern California I-zone, in which society tries to mix what doesn’t want to be together, and to segregate what wants to join. That tension focuses on the line in the dirt intended to separate what, increasingly, has no separation. The fuelbreak, or its most recent avatar, defensible space, is where the battle has joined.
§ The fuelbreak has a long history in the region. Local authorities were advocating (and financing) fuelbreaks as dual-purpose firelines and trails as soon as the mountains were gazetted as forest reserves. There were fuelbreaks in the San Gabriels before the Forest Service took over their administration. They provided, in principle, a means of access, a method to break up continuous fuels, a rudimentary fireline ready to activate when needed, and a visible display of administrative resolve. They inscribed their message across the great screen of the mountains. Unsurprisingly, the nation’s grandest experiment emerged from California; the Ponderosa Way was a 650-mile fuelbreak, built during the 1930s, that ran from Bakersfield to Redding. It was California’s dark double to the Prairie Shelterbelt scheme.
Over the years fuelbreaks have displayed a cycle of senescence and regeneration much like that of their surrounding vegetation. After each disastrous fire season, existing fuelbreaks are scraped clean and widened, and the system expanded. Then, they decay. They are expensive to maintain; other needs clamor for the money; critics scorn the ridgeline scratchings, which they regard as ugly and useless. The secondary system overgrows. Only the primary roads and those deemed most essential receive maintenance. Then the flames rush over the landscape, the public demands protection, and the fuelbreaks return. The life cycle of fuelbreaks, in brief, shows the same rhythm as the chaparral in which they are embedded.
In classic theory the fuelbreak assumes two forms. One breaks up the interior of the reserve in order to assist fire control. The principle is identical to that used in the built environment: create firewalls that retard spread and give firefighters time to wrestle the blaze into control. If sited in a forest plantation, the fuelbreaks would be incorporated into the design of planting. The most successful outside planted landscapes act as levees rather than dams; they flank the terrain- and wind-directed flow of the flames rather than try to stand against them. The other variety of fuelbreak is intended to guard a reserve’s perimeter; it serves as a biotic or fiery fence. This is rarely an integral feature, but rather something imposed onto and across a landscape that wants to behave differently. The reserve’s borders might cross firesheds as they do watersheds, which means fighting the order of nature rather than working with it.
Over time, the arrangement of fuelbreaks has remained more or less permanent, but its purpose has changed. The reason for persistence is easy to explain: this is where fire behavior and fire control argue for breaks, and such considerations don’t alter. But the nature of the fire threat does change. Originally, foresters recognized that the surest way to prevent big (and costly) fires was to contain small ones, and for this a network of access and buffers was necessary. Originally, too, they constructed a system to prevent the promiscuous (and sometimes malicious) fires set all around the reserve from entering.
But as the belief took hold that some fires were inevitable and good, and that fire control could itself be damaging, the pressure for those interior fuelbreaks lessened. They became more an act of political posturing, a signal to the public that fire officers were wary and prepared. The bigger change involved the perimeter fuelbreaks. Increasingly, these became less critical for keeping fire out than for keeping it in. The catastrophic fires were those that kindled in the mountain reserves and then spilled out onto the surrounding countryside, or more properly cityscape. The fuelbreak evolved away from a matter of protecting the reserve from the community and toward protecting the community from the reserve. It became a question of public safety, like debris dams and flood control channels.
It was one matter, however, to sculpt a fuelbreak along a continuous border across the flank of a mountain. It was quite another when the “border” was a speckled landscape of inholdings, fractal suburbs, and infrastructure nodes, or when, amid developed landscapes, it assumed quasi-natural features in the form of parks, greenbelts, and zoning for protected species that did the speckling. Critics bridled that by the time each enclave had its belt of clearing, there would be nothing left. The issue is particularly acute for San Diego because the city has 900 linear miles of ravines and some 55,000 houses along a fire-exposed fringe. If each entity put in the 100-foot or more clearances recommended by fire authorities, the practice would amount to 11 million acres and effectively wipe out relict landscapes. It would convert nature to city by stealth. It would, so the argument goes, create an urban desert visible from space.
Instead, critics want to focus on the structure itself, the home ignition zone, which is to say, the structure and its immediate environs. This is where surface fires and ember attacks actually take out houses, and it is often the sheer congestion of houses that carries the fire as each involved structure ignites those around it. The critics want fire protection to concentrate its hardening here, which would shrink the penumbral zone of clearing. If development is dispersed, flames would wash around the strictures, and if concentrated, they would dissipate as they ran out of fuel. A wildland fire, or an urban conflagration, would shatter into manageable house fires and then dissolve.
Behind this conception are related disputes about what fire management means. It begins with an argument about the nature of protection, or to state the issue slightly sideways, do you manage fire at its source or its sink? The fire-as-source group sees the problem as managing the landscape where fire originates. The other targets the places where fire strikes. The hydrologic equivalent is whether to control flooding by improving watersheds or by erecting levees and dams. The fire-as-sink group envisions the task as focusing on the assets at risk, both hardening individual structures and making the I-zone overall more resilient. It reasons that if the goal is to protect houses and the citizens who reside within them, then protect those houses directly, not remake the amorphous landscape from which the fires emanate in the vague hope of eliminating risk. In this view nature needs protection from overzealous and misdirected fire control. They each define mitigation differently. The source group focuses on the need to mitigate against fire; the sink group, to mitigate against unwonted fire prevention measures.
Each sees with different eyes the border between the fire and house, and accordingly each assesses fuelbreaks differently. The source group, intent on managing fire within its fireshed – not only to prevent escapes but for ecological purposes – wants interior fuelbreaks to help, and perimeter fuelbreaks to halt as much as possible. It can cite an honor roll of successes. The Harris fire, where burning out along the International Fuelbreak spared Tecate, Mexico. The Border 16 fire, where flames crossed north across the border and took only a solitary house, the only structure without defensible space. The Shockey fire, where a treated neighborhood in Campo shook off even Santa Ana-driven flames. The Banner and Angel fires, where burnouts along the Sunrise Fuelbreak shielded the town of Julian.
The sink group poses a counter-narrative. It sees fuelbreaks as ineffective when they are most required. The region’s vaunted defenses did nothing against the monster fires such as the Cedar and Witch that define the contemporary scene. Worse, they aggravate the abuses lavished on an already damaged landscape by creating grassy fuses to carry fire and channel invasive pyrophytes into unscathed chaparral. Giving every homeowner a personal fuelbreak in the form of overly expansive clearances called defensible space guts any hope of preserving a vestige of native plants and habitat. It means subversive urbanization by other means.
So the debate continues, each side more effective at criticizing the other than promoting their own agenda. Both groups, however, design with a particular fire and environmental risk in mind. But the Southern California scene is nothing if not dynamic. The representative fires keep morphing. The assets at risk keep moving. The only constant is the argument of neighbors across the wall, one rebuilding the wall and the other willing to let it decay.
Then the next conflagration comes.
§ Each side can point to failures and successes. Yet in the San Diego region there are two examples of enduring fuelbreaks that seem to perform exactly as designed. It’s worth pausing to examine how and why they work, and what their costs might be.
Fuelbreaks succeed best when they are integral to a built landscape, or when they are part of a planted agricultural complex. They have worked in pine plantations on the shores of the Baltic, the sand dunes of the Landes, and the Sand Hills of Nebraska. They have contained fires along railways lines, often combined with grazing, planting, and controlled burning. As greenbelts, they have shielded new communities, even cities. They have worked in India and Ghana to define and defend the boundaries of gazetted forests. In most instances the threatening fires do not scale up to conflagrations, and in no cases do fuelbreaks succeed by themselves, any more than fire walls will keep a building from burning down; but they buy time and assist firefighting.
They struggle when retrofitted or imposed over landscapes in defiance of terrain, wind, and fuels. When local conditions favor large fires, only very large fuelbreaks can help check them, and that effectively means type conversion, transforming whole landscapes, which in Southern California means housing tracts. Still, under less than extreme conditions, they can leverage fire suppression, helping channel a fire; and in miniature forms, as defensible space, they can encourage engine crews to stay with a house that they might otherwise yield to the flames. If fuelbreaks fail during extreme conditions, so do all the other strategies and maneuvers of fire management. The Big One continues to haunt wildland fire management.
There are, however, two exceptions, although they may prove the rule because they show what a strategy of fuelbreaks can cost. One is Camp Pendleton. On a map of regional fuelbreaks Pendleton’s dense network sits like the textured surface of a grenade. The camp is laced with roads and fuelbreaks, all mandatory to contain the burns kindled by endless live-fire exercises. But the Camp is also surrounded by a defensive belt, like a DMZ, that is annually cleared and burned. For what it is designed to do, the fuelbreak system works. It is integral, dense, comprehensive. Very few fires leave Pendleton, very few enter.
The other example is the International Fuelbreak that spans some 40 miles of the border with Mexico. It originated, as so many large fuelbreak projects did, in the 1930s when the CCC program demanded public works commensurate with unskilled labor on a vast scale. When the CCC left, so did the fuelbreak. It was revived in the 1950s by CalFire, this time using California Department of Corrections conservation camp labor. It decayed again. It revived forcibly during the 1990s when Operation Gatekeeper sought to control illegal immigration from Mexico around Tijuana. The flow of migrants moved east. Abandoned campfires pocked the chaparral, escaped fires swarmed over the mountains.
The International Fuelbreak then joined other efforts to secure America’s southern frontier. In 2002 an interagency alliance, using conservation camp labor, reconstituted the project. It began with a stretch two miles long and 300 feet wide, “with some vegetative islands for wildlife and aesthetics.” Plans called for extending the reach through the mountains for 30 miles. In the 2003 fire siege, with the Otay fire driving south and west under Santa Anas, the initial attack IC successfully burned out along the break and controlled the larger burn “with very limited resources.”
Limited on the fireline, but not limited socially. Such fuelbreaks are a significant cultural investment; they have to tap national funds and purposes; fire alone is an insufficient justification. A conflagration could rekindle their clearing but only some larger ambition could sustain them. And beyond apathy, or a distracted public, they carry environmental costs. Even with bottomless CCC labor on hand, the Forest Service experimented with chemicals to keep the breaks clear. It had enrollees spread arsenic, and later, when CalFire oversaw the network, agencies sprayed an herbicide that achieved notoriety in Vietnam as Agent Orange. The breaks became corridors for weeds and invasives.
Even a dense network still requires an active firefighting force; engines and fuelbreaks have to act in concert since protection is a social dynamic, not an inert piece of infrastructure. To commit to a model of fire control by fuelbreaks and engines, the threat from fire has to be high, for such landscapes can resemble the fire equivalent of a police state.
§ In 1989, four years before the cycle of Southern California conflagrations renewed, John McPhee published an essay that captured exactly the absurdist outrage that most of the country felt toward the region. “Los Angeles Against the Mountains” described the Sisyphean task of holding back the debris the San Gabriels continually shed, like a snake sloughing old skin. As with most Southern California stories this one involves fire.
The ecological narrative is simple. A big fire is followed by heavy rain that sends unstable regolith downstream. In extreme events the runoff gushes as a debris flow, as though a ridge liquefied and roiled down canyon full of mud and boulders. The social narrative is equally simple and predictable. It begins with debris dams constructed along the alluvial fans to stop the nuisance flows. The major debris events overrun them, and fill them, which means the old ones must be cleaned out, and new ones built further upstream. The process escalates. The defining consideration, however, is what to do with the debris. With the landscape downstream built out – the alluvial fan has become a cone of tract homes and mansions – there is nowhere to dump the fresh debris, which means the dams must fail. The solution is an “elegant absurdity” by which the San Gabriel Dam, first erected in the 1930s, must be continually cleaned out and the only place to haul the fill is further up canyon. “They take the debris and carry it back into the mountains,” as a spokesman for the Department of Public Works explained to McPhee, “where they create a potential debris flow.”[ii]
Yet this is much the same formula for fire. Substitute fuelbreaks for debris dams, fuel for debris, conflagration for debris flow, all for the protection of private houses so they can survive in harm’s way only because the cost of protection is absorbed by the public. Rather than fix behavior, in this case the real estate market, the region invests public monies (and national insurance funds), much of it from outside California, into infrastructure. The debris – fuel – regrows, and either it is mechanically cleared or it burns.
Its fuelbreaks thus do for Southern California what massive levees do for New Orleans. It allows a city sited for economic reasons to hold out against prevailing natural forces. When its economy or its social resolve falters, the sea, for the one, and fire, for the other, rush in. Over and over, the problem repeats with a slight increment of intensity added to each cycle.
§ So it all continues. The fuelbreaks reappear in the same places. They cause the same disturbances. They boost firefighting capabilities against the lesser burns. They fail during the conflagrations. They reappear under new names or modified to accommodate new realities – housing tracts rather than ranches, McMansions rather than barns. In San Diego the contrast between mountain and plain is less intense but its discourse is just as fierce.
Apologists explain that anything built can only meet reasonable standards, not everything imaginable. Engineers design for a 50- or 100-year flood, not a millennial one, or for a 5.8 or 6.7 earthquake, not for a Richter 8. Similarly, fire agencies traditionally plan for an average worst event. But Southern California operates on extremes, not means; there is no “average worst.” When it breaks, it tends to break completely. You might be able to stop the flow of flames but not the shower of sparks. For every reason advanced to keep fuelbreaks, there is a reasonable objection, and a reasonable objection to the objection, like debris dams backing up debris dams. The pragmatic solution would be to shift the argument about whether, abstractly, fuelbreaks are right or wrong, but whether, practically, in particular places, they are useful or not.
The real reason the discourse endures is because those wildland firewalls are tangible emblems of philosophical differences. They trace out separate conceptions of fire and its purpose, they define the border between competing ideas about how to live on the land. So even as they are scraped down and grow back, the old lines of debate persist, like buried faultlines that from time to time rupture under the stresses of deeper forces. Those walls are, in the end, the lines of negotiation between a nature that doesn’t care and a society that doesn’t want to worry.
July 2011; revised, December 2011