Monday, March 26, 2007

Fire is a river that runs uphill

Remember the "dreamscapes" homes featured in the Los Angeles Times' west magazine? When I asked what the four homes had in common besides killer views, no one guessed that the homes are all in harm's way.

The ocean view home in Pacific Palisades was built after the previous house slid down the hill. The Malibu home replaces one that burned down in 1993. The hilltop studio is just that, and situated amid a grove of oily, fire-prone eucalyptus trees. The Palm Springs house does not look like it is in imminent danger, but it is essentially a glass box sitting next to an active earthquake fault.

Years ago, I listened to a fire modeler from Los Alamos National Lab. The takeaway message from his talk was that fire is a river that runs uphill. On flat land, in the absence of winds, a fire will burn itself out after it has exhausted the fuels in the fire perimeter. To fight the fire, you need only create a firebreak which denies the fire of the fuel it needs to maintain itself.

Flames and hot embers rise. On a hill (still in the absence of winds), the fire will keep moving uphill, picking up fresh fuel, until it can climb no further. Living on a ridge line is doubly dangerous because you are in not one, but two firesheds. A mountain top compounds the danger even further. But that is where the killer views are.

Living below the ridgeline, say on the ocean side, is not a guarantee of safety. Strong winds (can you say Santa Ana?) can blow a wall of flames over so that it curves up and over mountain ridges.

After the LANL scientist had his say, I turned to the fire chief (of a major metropolitan city with many people living at the urban wild land interface) sitting next to me and asked, "Why do you give people building permits for those homes?". He replied that he didn't. He denies them the first time because they are unsafe.

But the people who have the financial resources to build those homes are not used to hearing no. They call their buddy, the mayor, and then the mayor calls to ask the fire chief to chew his hide. To save his job, he gives the rich and powerful what they want, even though he knows it is a bad idea.

It costs a lot of money to fight fires in those mountainous subdivisions. That cost is subsidized by people living in the flatlands with views of the apartment building 10 feet away. The fire chief doesn't want to expend his department's meager resources on defending yet another home deliberately put in harm's way. But he feels like he has no choice.

Similiarly, the land in Malibu has a habit of sliding away when it rains. Caltrans does a bang-up job, continuously clearing the rocks that fall on the Pacific Coast Highway so that the rich and powerful are not inconvenienced in their commute. (The same goes for "Devil's Slide" near San Francisco.) That is money that is not spent fixing potholes in the flatlands, home of plebian chumps.

Some will say that those people pay a lot of taxes for their expensive homes. That may be, but more taxes are paid in the flatlands simply because more people live there. Yet, the cost of providing services, on a per capita (or per dwelling unit) basis are disproportionately high for the extreme view neighborhoods.

Perhaps it is time we institute something like Boulder's "blue line". Above that line, you can build a home, but don't expect any city water or fire protection. That preserves personal freedom, but doesn't ask someone else to shoulder your risk. (Well, unless you count the insurance risk pool.)

Read Heat Invades Cool Heights Over Arizona Desert.
Since 1990, more than eight million homes have been built in Western areas that foresters call “the urban-wild land” interface, also the focus of recent federal firefighting efforts...

Last year, wildfires burned nearly 10 million acres in the United States — a record, surpassing the previous year. The Forest Service has become the fire service, devoting 42 percent of its budget to fire suppression last year — more than triple what it was in 1991.
One major reason that fire fighting in the western forests has become more expensive is the number of structures (homes) being built in the trees. One Colorado newspaper had the guts to run a story questioning if our firefighters should risk (or lose) their lives protecting the vacation homes of the rich after twelve firefighters died in the Storm King Mountain fire.

It is an issue of fairness. Why should poor and middle class people subsidize the requirement of the rich to have their views?

(Of course I am jealous. I would love to have a killer view and a glass house to frame those views. Alas, my scientist salary does not allow that anywhere within bicycle commuting distance of my job. Maybe I can paint a mural on the apartment building next door to improve my view.)

The Hollywood Hills fire behaved just like a computer modeled fire!
Read Wildfire Weather to find out why I am so obsessed with wildfires.


  1. I generally enjoy your blog but I just wanted to say this article had me thinking all day. Thanks.

  2. Anonymous14:09

    Very interesting - there are definitely arguments on both sides of the issue. Interesting how money and influence usually wins out though, despite the merits of the other side's arguments. I wonder what kind of backlash it would take to actually resolve the situation?

  3. Thank you for sharing this info. As the San Bernadino fire rages, my hopes are for a quiet fire season in San Diego.

    1. @Judy J I hope you don't live in one of the 'wind corridors' (aka fire corridors) of north SD county. They were developed last for a reason. (As are homes in flood plains.)


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