Fighting It by Letting It Burn
Among the many cultural differences along the U.S.-Mexico border is a widely differing approach to the task of fighting brush fires.
Mexican governments -- partially because of tight budgets -- do not attempt the quick suppression of brush fires that property owners and politicians in the United States demand of their firefighters.
Mexican officials, backed by some U.S. academics, believe that having several medium-sized brush fires in one season is preferable to having one large brush fire that can destroy homes and cost lives. Smaller fires burn the fuel that can feed a large fire, they note.
The catastrophic fires in Southern California last week, which destroyed thousands of homes and killed 22 people, have convinced Mexican officials that their approach is correct. In Baja California, only 10 houses burned and two elderly people died of smoke inhalation. One fire near Ensenada ultimately ran out of fuel.
In Baja, fires on the outskirts of cities are allowed to burn themselves out. Ranchers and squatters actually start fires on their lands to clear brush and get rid of junk and trash.
Such “controlled burns” are done more sparingly in the United States. One such fire, set to thin a forest in northern New Mexico three years ago, spread with disastrous consequences, burning 200 homes in the town of Los Alamos before it was extinguished.
In Mexico, fires can be set or allowed to burn with less risk to residential neighborhoods because there is less development in rural areas. That is likely to remain the case until city services are more readily available in the countryside.
“Well, let it burn. What’s the problem?” said Jose Luis Rosas, executive coordinator for Baja California’s civil protection agency, echoing the common reaction in his office to reports of blazes in the region’s grasslands, forests and arid hills.
The result in Mexico, some experts said, is a patchwork of tall, thick brush, newer, less flammable growth and recently blackened earth, which combine to provide buffers to keep fires from reaching the proportions of the recent Cedar and Paradise blazes in San Diego County.
Richard Carson, professor of economics at UC San Diego, is one academic who favors the Mexican approach. He says statistics bear out the wisdom of letting brush fires burn unless they threaten structures.
He said Mexican figures on lives lost and acreage burned are considerably lower than those in the United States though the same potential for fire exists.
“The ecosystem doesn’t stop at the border,” Carson said.
The success of U.S. fire agencies in knocking down brush fires in the early stages seems to ensure that a mega-fire will erupt at some point, Carson said.
“The difficulty is that you have so many houses in the [U.S.] backcountry that you suppress fires to protect houses and you don’t get the natural burn,” he said. “The other way you can do it is controlled burns [but] air pollution authorities are reluctant to have controlled burns.”
The Cedar and Paradise fires, said Carson, a resident of the Scripps Ranch neighborhood of San Diego, probably mean the city will not see another big fire soon because so much fuel has been consumed.
“They do it better down there, trust me,” said Richard Minnich, earth sciences professor at UC Riverside, who also favors the Mexican approach of allowing grazing to reduce grass on open land and then allowing small fires to run their course.
Minnich added that the United States exacerbates the potential for disastrous brush fires by adding additional fire personnel in the summer to knock down blazes. In the fall, there are fewer firefighters but the Santa Ana winds that can propel blazes are at their height.
“Fire suppression skews the fire season to the fall and makes it more dangerous,” he said.
The Minnich-Carson thesis is not universally accepted. Researchers for the U.S. Geological Survey, for example, do not buy the idea that fire suppression leads to bigger blazes in the long run.
Jon Keeley, an agency fire researcher who studies both Southern California scrublands and Sierra Nevada forests, said a review of 19th century records indicate that fires consumed even more acreage in Southern California, including a fire in Orange County in 1889 that burned more than 500,000 acres.
In Tijuana, residents are unaware of the dispute in the United States over the connection between fire suppression and enormous brush fires. But they know the fires in Southern California left a pall of smoke over their city, forced the closure of schools and sent 55 people to the hospital with breathing difficulties.
On Sunday night, Alejandro Avendano was standing atop his two-story cinderblock house observing the Mine fire, which consumed nearly 50,000 acres just over the fence from Mexico.
“You could feel the heat,” the 48-year-old schoolteacher recalled. “Tijuana was covered in ash; it was like we each smoked 20 packs of Marlboros.”
Avendano said he never feared the fire would threaten his home. But even as he spoke on his dusty street in Otay Mesa, several small fires could be seen smoldering on the ranches and junkyard lots surrounding his hilltop neighborhood.
Fires in Tijuana, Avendano shrugged, “just burn.”
Like his, many Mexican houses are built of concrete and cinderblock because wood is too expensive. Concrete and cinderblock are less vulnerable to fire than, say, the shake-shingle roofs of the Scripps Ranch, where 345 homes burned.
The fires also allowed for a kind of political turnabout. It is common for the United States to assist Baja California with a variety of problems. This time the roles were reversed.
A strike team of 20 volunteer firefighters from Mexicali crossed into San Diego County to help fight the Mine fire.