Should planning departments in California force developers to steer clear of fire-prone areas? Or should building departments force developers to fireproof their neighborhoods instead?

Frankly, I'm a little tired of posing this question, because it comes up every time there's a big set of fires. But when you're looking at a couple of thousand houses lost and more than a billion dollars in property damage, it's a question you have to ask.

The last time this question came along was four years ago – almost to the day – in the wake of the last enormous conflagration, in which more than 20 people died and 3,600 homes were destroyed. The answer at that time pretty clearly was in favor of fireproofing neighborhoods rather than avoiding fire-prone areas. Since then, there has been little evidence that policy is changing.

But the California Department of Forestry & Fire Protection (CDF) has been thinking about it. And maybe it's worth a fresh look, if local governments are willing to think about it. As usual, perverse financial incentives built into the state system make city officials less likely to think about it.

"Avoidance" is one of those good planning ideas. You simply draw a line around fire-prone areas and don't allow construction inside the line. Kind of like earthquake planning. Or classic McHargian environmental planning.

But in an era when California is running out of places to put people and property rights advocates have the upper hand, avoidance is not always viewed as a viable option. To be fair, there's also some evidence that better fire mitigation at the neighborhood level is working.

The turning point in the avoidance v. mitigation debate came during the last devastating fires four years ago, when the Stevenson Ranch subdivision near Santa Clarita in unincorporated Los Angeles County survived a nearby fire without much trouble. A front-page story in The New York Times documented how a wide variety of mitigation practices required by Los Angeles County building inspectors created a mostly fireproof subdivision. Most of the post-mortems focused on building codes, not planning. The emphasis was on mitigation, not avoidance. The City of San Diego, which bore much of the damage during the 2003 fires, finally outlawed wood roofs.

This time around, attention again quickly turned to mitigation rather than avoidance. Even as the fires were still burning, the Los Angeles Times returned to Stevenson Ranch to confirm that it still had not burned down thanks to the effective creation of defensible space.

As for the use of land use planning for avoidance, most everybody was fatalistic. Referring to the San Bernardino Mountains – again in flames this time around – San Bernardino County Supervisor Patti Aguiar told the Riverside Press-Enterprise in 2004: "A moratorium probably made sense a long time ago, if you didn't want anybody up there. But now, everybody's already up there. It's pretty darn late."

CDF, however, hasn't stopped thinking about avoidance as opposed to mitigation, and with good reason. As the state fire agency, CDF has primary responsibility for fighting wildfires — especially in rural areas, but also in semi-urban areas on the perimeter of the Southern California metropolis. CDF fights wildfires not by putting them out immediately, but by containing them and allowing them to burn out. Among other things, this appears to be a more environmentally sustainable approach, given what the experts call California's "fire-driven ecology."

But when structures are present, CDF must by law focus on the structures, not on the wildlife. This often requires redeploying firefighters and other resources from containing a far-reaching wildfire to protecting a small geographical area with structures in it.

In the past few months, both the state fire chief and the Legislative Analyst's Office (LAO) have tried to highlight the problems that subdivisions in fire-prone areas are creating.

In a report issued last March, the LAO noted that CDF's budget had increased 83% during the last decade, from $475 million to $869 million. This fiscal year's budget for CDF tops $1 billion. The LAO attributed much of the increased cost to additional development in the wildland-urban interface, which state fire officials like to call the "WUI."

In recent years, the LAO noted, the State Responsibility Area – the geographical area to which CDF must by law provide wildland fire protection – has remained stagnant at about 31 million acres. But just from 2000 to 2005, the number of houses in the State Responsibility Area increased by more than 10% – from around 780,000 to around 860,000 units.

Then, at the beginning of the fire season in June, CDF Director Ruben Grijalva devoted his weekly message to an unusually detailed and insightful analysis of the wildland-urban firefighting problem. Grijalva zeroed in particularly on the development question, noting the trend of equity refugees moving away from urban areas and into wildland areas. He placed particular emphasis on the issue of watershed preservation in wildland areas, saying that low-density forest subdivisions can harm watersheds that all urban Californians depend on.

In general, local jurisdictions – especially counties – have not paid much attention to these concerns. That's not surprising. As with so many other land use policy issues in California, it is at least partly a question of who bears the cost – the local governments or the state.

Buried deep within the rules as to what constitutes a State Responsibility Area is a density rule. In unincorporated areas with timberlands, rangelands, or watersheds, counties bear financial responsibility for firefighting if subdivisions contain more than 3 units per acre. If a subdivision contains less than 3 units per acre, then the state has financial responsibility to pay for the firefighting.

In other words, if counties are inclined to permit subdivisions in fire-prone areas to begin with – and most rural counties in California are so inclined – then they have a financial incentive to lower the density so fighting wildfires is CDF's problem. The LAO report from last spring suggested that the minimum density should be changed to remove this perverse incentive.

If there's one bright spot in all this, it's Riverside County. Thanks partly to new state fire hazard maps, Riverside is taking fire risk seriously, and considering the possibility of creating a fire hazard zone similar to the 100-year floodplain that would not permit development.

So not everybody has given up. And that is a good thing. Because surely if there is one thing that land use planning is well-suited for, it is mapping out hazards and helping to avoid them.