Fires, Floods, and Human History -- The Value of a Single SoCal Creek

Riparian Corridor of Big Tujunga Creek in the Angeles National Forest as it flows down toward Los Angeles. Credit: Edward Belden, National Forest Fund.

I heard the water splashing long before I saw its fall.

The sound -- a clear, thin cascade -- drew me east toward the dawn as I moved up the gravel-rough horse trail paralleling Thompson Creek diversion channel in northern Claremont. Streaming west in the concrete bed was a slow flow from the previous day's rain: I knew more about how these waters would get to the Pacific than I did about their source.

The deep ditch drops away from Thompson Creek dam, one of a number of flood-control structures built in the aftermath of the devastating 1938 flood that crashed through Claremont and much of the Pomona Valley and that wreaked havoc through the Southland. The channel cuts along the base of the foothills before turning south into the city of Pomona, where it merges with other ditches and culverts, an infrastructure that swings past Ganesha Park and Cal Poly-Pomona and then slides by nondescript warehouses and industrial parks before slipping between low-lying hills in Pomona's southwestern quadrant. As it pushes past La Puente, City of Industry, and Avocado Heights, this long-running channel finally converges with the San Gabriel River hard by the 60 and 605 freeway interchange, a multi-layered intersection of the riparian and vehicular.

Story continues below

From that confluence, it is a relatively straight shot to the sea. But not so the movement of water into this artery-like construction , a branch of which I hoped to trace that early weekend morning. The splish-splashing I heard signaled I was close to Sycamore Canyon and the unnamed creek that over the millennia has given shape to the rough floor through which it trickles and the manzanita-choked walls that rise above.

Crossing the short bridge that leads over the Thompson Creek ditch and into the canyon's mouth, I was struck that as a landform there is nothing particularly unusual about the 144-acre site, one of hundreds of wedged-sized ravines that give contour to the San Gabriel foothills.

As best anyone knows, nothing of great significance has happened at this spot, either.

For the Tongva, who hunted and gathered across the broad expanse from present-day San Bernardino to the Santa Monica highlands. it was among many coastal sage-scrub ecosystems whose resources nurtured their daily life. Here, as elsewhere, they found meat and fish, fur, berries, nuts, and seeds, bark from sycamores and manzanita, leaves from sage and buckwheat.

Treatment map of Sycamore Canyon, courtesy L.A> County Fire Department.
Treatment map of Sycamore Canyon, courtesy L.A> County Fire Department.

The communities sustained by this plenty began to diminish with the arrival of the Spanish missions, and the diseases and technologies they unpacked in the inland valleys of the Los Angeles basin. As the indigenous people wilted before imported pathogens and were conscripted as labor for new forms of sedentary agriculture, Spanish ranching operations began to mow down the hillside and canyonland habitats through the grazing of sheep, goal, and cattle. It's doubtful whether they or their colonizing replacements, the Euro-Americans who flooded into California in the mid-19th-century, paid any special attention to this narrow gap in the foothills.

Sycamore Canyon would have remained undistinguished and indistinguishable had not its upper folds been bulldozed and flattened for the construction of a mid-20th-century upscale development dubbed Claraboya. To domesticate the ridgelines and outcroppings that surround its high-priced homes, the new residents started planting non-native trees, shrubs, and grasses, all heavily irrigated. The outflow of fertilized-laden water nourished the spread of invasives down the slopes and not incidentally tainted the canyon's creek. The increased density of woody vegetation turned the crests of these once-golden hills emerald, a chromatic shift that spelled trouble in the fall of 2003.

Late that October, a firestorm erupted across Southern California, fueled by strong wilds and a desiccated landscape that had not burned in decades. One of the massive conflagrations, the Old-Grand Prix-Padua fire, torched upwards of 170,000 acres along the southern flank of the San Bernardino and San Gabriel mountains, killed six people, destroyed more than one thousand homes, and cost over $50 million to suppress.

Among the many neighborhoods that were evacuated in advance of the rapidly moving fire was Claraboya. The precautionary move was a good thing: more than a dozen houses there were incinerated as the inferno swept from crown to crown, and crackled through the thick underbrush. Sycamore Canyon became a swirling cauldron, shooting flames up a ladder of vegetation to engulf residences above.

When the fire was contained in early November, the canyon was a smoldering ruin. Its slopes were charred, and along the creek, toppled in a maze, were the blackened trunks of eucalyptus, oak, and sycamore. On the same day that Claraboya residents were allowed to drive up the aptly named Mountain Avenue to inspect the damage, city officials issued an advisory: "Anyone wanting to access Thompson Creek Trail should do so only with great caution as there is damage to much of the area surrounding the trail." The Padua fire had been so destructive that Sycamore Canyon was sealed off for the next ten years.

Earlier this month it reopened after a multi-year reclamation project. Clean up had begun almost immediately. In the mid-2000s, the forestry division of the Los Angeles County Fire Department reintroduced grazing to the area, managing a herd of goats to reduce vegetation fire hazards on unburned slopes below Claraboya. In collaboration with the city and the Los Angeles Conservation Corps, its Camp 19 hand crews then moved in clear away debris, particularly that which had crashed into the creek, and reestablish a single-track trail that snakes into the canyon, and other running uphill to ultimately connects to the 1620-acre Claremont Hills Wilderness Park that lies to the north.

The most sensitive part of the agency's work, which hewed to the city's commitment to restore the area's native ecosystem, was to remove 35 dead or dying eucalyptus that had been planted or settled into the rocky soil. Their removal for reasons of public safety will be followed by a phased logging of another 100 eucalyptus that had survived the 2003 fire. This projected harvest is essential, consultants from BonTerra informed the city, for "Eucalyptus trees release chemicals into the surrounding soil that inhibit the establishment of understory plants," a biological defense mechanism that would undermine the "regeneration of the park." Once they are cut out, Sycamore Canyon will have a better chance of recovering its indigenous habitat.

To do so has required additional human intervention, a visible hand everywhere evident as I hiked into the canyon. Controlling winter rain-generated debris flows that can carom down scorched and eroded slopes required the building of a substantial steel-and-timber barrier, embedded in concrete blocks, that spans the lower creek to protect the flood channel into which flows. Upstream, earthen check-dams have been built to further arrest churning waters.

The planting of 360 oak and sycamore seedlings within the riparian zone is noteworthy too, for the goal is replicate the canyon's historic canopy and root structure, bringing much-needed shade to summer-heated soils and stabilizing banks and slopes. Landscape architect Mark von Wodtke, co-founder of Claremont Environmental Design Group and a contributing partner to the restoration project, enthused to the Claremont Courier: "We have been able to demonstrate, here in this canyon, how we are able to regenerate nature and the natural environment."

If successful, this regenerative aspiration, like the equally ambitious project that the National Forest Foundation, the U. S. Forest Service, and a host of partners are mapping out for the Big Tujunga watershed, which was badly burned in the 2009 Station fire, may mark a significant turning point in our understanding of what water means in, to, and for Southern California.

So it occurred to me when, after tramping about a mile along the canyon floor, I retraced my steps, following the creek's low-pitched gurgle to where it pooled in a depression before draining into a pipe that sluiced it toward the Thompson Creek flood-control channel -- and from which that morning it spilled so musically.

The difference between the restored creek bed and the concrete ditch is not simply that one is organic and the other engineered, though that's true enough. It's a little more complicated to acknowledge that these two systems are intertwined, or hybridized, yet they also reflect differing conceptions of our role in managing water in semi-arid Southland.

The Thompson Creek channel has had but one purpose: to capture any and all runoff and flush it to the ocean as fast as possible. Its developers did worry about how ecologically sound the upper reaches of its watershed was. What mattered was moving the wet stuff from the moment it hits the ground to the split second before the San Gabriel River rushes into the Pacific at Seal Beach. Theirs was a technocratic impulse and imperative.

The restoration of Sycamore Canyon is every bit as managerial in its motivation and orientation. Foresters, ecologists, landscape designers, and planners, experts all, have rearranged hillside and creek bed, selected which tree species should be logged and which should be cultivated, and used goats, chainsaws, shovels, hammers, and nails to build a model terrain.

The difference between these visions lies not in tools but in intent. Shaped by the history of damaging floods, mid-20th-century engineers defined moving water as a danger or a waste; to control the former or get rid of the latter was built into the complex web of dams, culverts, ditches, and channels that give shape to modern Los Angeles.

Yet for all its effectiveness, this rigid plumbing system also robs the land of its health; by diverting water away from local aquifers, by straitjacketing once free-flowing rivers, it disables these natural systems and the ecological communities that depended on them.

Hurt too is the public's health, a claim that is tied to an all-encompassing ecological ethic planted with each seedling on this small patch of ground inside the Thompson Creek watershed. "We abuse land because we regard it as a commodity belonging to us," Aldo Leopold argues in Sand County Almanac. "When we see land as a community to which we belong, we may begin to use it with love and respect." Essential to that feeling of respect is accepting that our use "is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise."

In Sycamore Canyon, Claremont is trying to get it right.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

We are dedicated to providing you with articles like this one. Show your support with a tax-deductible contribution to KCET. After all, public media is meant for the public. It belongs to all of us.

Keep Reading