Shaping the California Wildfire Battlefield


The year 2010 marks the centennial of the start of a national wildland fire suppression policy that was instituted after a particularly devastating wildfire. The “Big Burn” or “Big Blowup” of August 20-21, 1910, destroyed three million acres of forest and several towns in Washington, Idaho, and Montana; 87 people died, 78 of whom were firefighters. Although the credit and honor go to all wildland firefighters for their efforts—past and present; paid and volunteer; state, federal, and local—we don’t seem to be winning this war. As the most recent California fire marshal and a 30-year veteran of cutting, squirting, chopping, flying, or otherwise fighting fire on the ground, in the air, and behind the desk, I believe California is finally changing its fundamental approach to its wildland urban interface (WUI) fire problem.





Wildfire Scenario


It’s 0700 hours, and the first Incident Operations Briefing has just finished. Strike Team Leader-Engine (STEN) Ken Davies works his way back to the engines with the maps and the incident action plan to start the shift briefing for Strike Team 1120 Charlie’s assignment, structure protection on Division Zulu. “This fire’s a mess with multiple heads, too much wind and smoke, and predictions for it to get worse throughout the afternoon and evening,” he tells the firefighters.

As Davies briefs his five engine companies for the task ahead, he passes on critical safety and tactical information. “First, the bad news: We have 100 homes to protect in our part of the Division; most residents have evacuated, but others have refused to leave. There will definitely be life risk if a wind shift brings the west flank straight to us. The good news is that access is good, hydrants are up and running, the homes were built to code in the past few years, and the community has prepared for wildfire. We can defend this line safely.”

As the crews load up and head out, the STEN thinks about how different this division assignment is from a few years ago when there were too many close calls in one season. What makes the difference here is all the work that happened before the incident—the good intelligence on the community, the planning for roads and water, the outreach between the fire department and the homeowners, and the homes’ ability to withstand exposure to the ember storms of wildfire. “It’s working,” he thinks. “This prevention and planning stuff is making a difference. We’re defending homes we couldn’t before.”

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(1) Aerial imagery showing designated Moderate (green), High (tan), and Very High (red) Fire Hazard Severity Zones in a local California jurisdiction. Zones account for up to one-half mile ember travel in high-wind conflagration WUI fires. (Photo courtesy of California Department of Forestry and Fire Protection/Fire Resource and Assessment Program.)

This is the core message behind the “Shaping the Battlefield” (STB) concept and how it applies to California’s target-rich wildfire environment, with as many as five million homes in the WUI. Borrowed from the U.S. Marine Corps and adapted to the fire service, STB combines our historic fire suppression-focused approach with a before-the-battle perspective that is more comprehensive. STB recognizes that success in prevention, mitigation, and planning beforehand translates directly to success in the engagement, whether it’s a military or a firefighting operation. Efforts focus on planning, information gathering, mitigation, and risk identification—all of which will be used during the firefight.

Preparing for the WUI battle requires not only training, equipment, and staffing but also obtaining and delivering field intelligence, implementing effective building construction and community design measures, including the public in emergency preplanning, and managing fuels—beginning with the individual home and its defensible space.

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(2) Roof type data obtained by aerial photography using hyperspectral imaging, which provides detailed information on vegetation, building, and other land surfaces. This information is useful in prevention and the operational phase of fire protection. [Photo courtesy of the Moraga Orinda (CA) Fire District.]

California’s wildfire prevention and mitigation efforts focus on integrating an emergency’s planning phase with its operational phase. Both are absolutely critical to reduce losses, and both define the success of public safety outcomes. The main components of the WUI-STB approach are firesafe land use planning, building design and construction, vegetative fuels management, and community and first responder education.

Focusing on these areas means that although fires will continue to increase in frequency and severity and will still be large, chaotic, and risky, they will cause less damage. Firefighters can defend ground more effectively and safely when homes include defensible space and are designed to weather the ember storm with fewer ignitions, roads allow for safer egress, and residents are familiar with the local emergency plan.




California’s large-scale land use planning tools include the state-required General Plans that cities and counties adopt and use to guide local development policy. By state law, each General Plan must address wildfire safety in the Safety Element if the jurisdiction has any designated Fire Hazard Severity Zones.

California also addresses wildfire directly through the California Emergency Management Authority (Cal EMA) Hazard Mitigation Plan, which is further refined at the local level. Subdivision-scale development plans require that the Environmental Impact Report evaluate the project’s effect on wildfire public safety and the environmental impact of fire, fire suppression, and fuels management. Many areas adjacent to federal lands have prepared Community Wildfire Protection Plans, which are incorporated into local land use decision making. Fire Protection Plans that incorporate fire behavior modeling and mitigation prescriptions customized for the building project are becoming more common for larger subdivision projects. Also, every home that is now built in a state or locally designated Fire Hazard Severity Zone requires certification for 100 feet of surrounding defensible space, access and water provisions, and ignition-resistant construction.


Wildfire Scenario


“20 Charlie—Engine 30,” the captain responds over the handheld radio as STEN Davies checks in with his engines on Division Zulu. “We are in place and glad to report that there’s plenty of room to turn around and we have several working hydrants.” Davies notes each of the engine locations and addresses on his map and checks his laptop for the latest aerials and overlays that give him intelligence on where their vulnerabilities are.




The California Building and Fire Codes (CBC/CFC), state-amended versions of the International Code Council (ICC) model building and fire model codes, have California-specific chapters for residential and commercial construction in the WUI. These provisions, embedded mainly in the CBC Chapter 7A, are the result of several years of research, laboratory testing, and technical committee development and are continually evolving. Local building officials are responsible for enforcement during the permitting and inspection phases of construction. The provisions are based on reproducible testing standards that are designed to mimic wildland exposures and on damage assessment findings gathered over the years by U.S. Forest Service Fire Scientist Jack Cohen and California Department of Forestry and Fire Protection (Cal Fire) Division Chief Ethan Foote.

They focus on reducing the home’s ignition potential rather than increasing its hour-rated construction. The goal is to keep the home from igniting instead of just slowing the burndown rate. They cover roof types (Classes A, B, and C), eave and vent design and screening for embers, wall coverings, dual-pane windows with tempered glass, and deck materials. Like all CBC and CFC provisions, these are statewide minimums for construction; local agencies must use these standards or adopt more stringent ones. All homes now built in California in a designated Fire Hazard Severity Zone must be built to these code standards. Mobile or manufactured homes for sale in the state are also included in these requirements through the California Housing and Community Development Agency, which regulates that industry.


Wildfire Scenario


It’s 1500 hours and, just as feared, the east winds are picking up and the west flank has turned into a running head. “All units on Division Zulu, acknowledge position and personnel”—a heads-up radio alert that things are going to be serious here real soon. Davies acknowledges for the Strike Team and gauges the wind—30 miles per hour (mph), steady, with gusts to 45 mph. The embers begin to come down—not ash but the glowing little coals that signal a firefront on its way. Davies runs the safety checklist again and drives around the subdivision, checking on the crews and their readiness.




It’s important to break down WUI fuels into two types, structural and vegetative. Building standards address the home-as-fuel-type issue by improving ignition resistance, exposure, and building materials. Vegetative fuels are most effectively addressed through a linear perspective: The closer the fuel is to the home, the more impact it has on structural survivability. This approach recognizes that the type of wildfire we are trying to impact the most is the WUI fire.

By law, the required defensible space extends 100 feet immediately adjacent to a structure on all sides and is the most critical fuels management goal. This space must be established for homes to have a reasonable likelihood of survival without direct fire suppression. Usually, the local or state fire department performs the Defensible Space Inspection, if it is done, although some jurisdictions contract this out to private vendors. Some use local Firewise or FireSafe community groups. Both these programs work collaboratively to bring the wildfire preparedness message to homeowners and supply volunteers who assist the local fire department in community outreach. Many jurisdictions have no provision for an organized inspection process, and the individual insurance carrier may inspect the property.

Currently, much of the WUI prevention and mitigation discussion in California centers on the methods, training, and collaboration required to ensure that millions of homes have a reliable defensible space that protects the homes and the firefighters. Vegetative fuels management also addresses the area beyond the home through the creation of community fuel breaks (defensive firefighting zones), designating streets as fire evacuation corridors, and creating larger thinned-fuel mosaics that are more wildland in nature than the WUI. Each of these fuel treatments has a different purpose and impact on the wildfire behavior and risk potential.

Based on past experience, most homes burn from exposure to embers or to adjacent house fires, so the fuel mitigation priority order is the house; the yard directly adjacent; the house next door; the community vegetation; and, finally, the regional vegetation.


Wildfire Scenario


E-30’s firefighters pull the mobile line and put their goggles down. The embers are raining down hard now; the wind is driving them everywhere—down their jackets, under the engine, into the bushes, and onto the decks. Small fires ignited by the embers have been starting for a while now, but so far they’ve kept up with them. Most homes haven’t needed any action, unlike a few years ago when too many roof and deck fires overwhelmed firefighters. The main fire is about 1,000 feet out, but it is coming fast. All the residents are out—at least the ones in their area.




As in structural fire prevention, all of a building’s built-in fire safety features can be wasted effort if the occupants have no idea of how to respond to an alarm, exit effectively, or maintain their safety systems. This also applies to WUI fire protection: Communities must be specifically educated and trained on how and why their home defense features must be maintained, how their emergency alerting system works, how to evacuate and to return, and what to realistically expect from the fire service in large-scale WUI events.

California has had a long-standing community approach to WUI fires with the 15-year-plus Firesafe Council approach. In some areas of the state, the Firesafe Councils are deeply embedded within the fire department structures; in other areas, they are almost completely independent, with separate boards and funding. The national Firewise program has also been adopted in several areas. The “Ready, Set, Go” program, which relies heavily on community preparedness and evacuation actions, was recently adopted by some southern California jurisdictions and endorsed by the fire service. The key goal is to ensure residents and responders are communicating what appropriate preevent wildfire actions to take, what will be asked of residents during a significant fire, and what the risks are.




Finally, the education of the public safety first responders themselves is crucial. This reaches beyond the currently required training for wildfire suppression tactics to include multijurisdictional training on the National Incident Management System/Incident Command System (NIMS/ICS), large-scale evacuation drills, emergency operations center (EOC) and incident command post (ICP) relationships, and communications and information/intelligence-sharing strategies. Communities where public safety leaders have adopted a strong “unified command” approach to planning, preparation, training, and community outreach are finding themselves far better prepared when the chaos of conflagration wildfire hits. California is in the midst of moving toward this as our collective experience with homeland security issues and natural disasters continues to reinforce our commitment to unified command.


Wildfire Scenario


“E-30—Priority Traffic!” shouts the captain as he tries to get through on the radio. “We have a residential structure fully involved at 112 Caliente Court. We are taking exposure action only—no life threat!” The ember storm has developed into a firefront with flames 50 feet high pushing heat at the homes. Davies is keeping close tabs on his crews and getting frequent updates on fire progression from air support overhead.

After 10 minutes, E-30 reports that the structure is down and the flamefront has moved past their position. Davies does another check-in, then reports back to the Division Group supervisor that the worst is over, one structure was lost, and all crews are accounted for. He reflects that, all in all, it was a well-executed firefight—demanding and with some loss, but no close calls and 99 homes saved.




The five STB components above have been effective in reducing the WUI fire risk. They represent a holistic approach to the WUI problem and focus on the planning, prevention, and mitigation parts of life and property fire protection. In the years ahead, these actions, combined with a continued strong suppression capability, will enable our firefighters and the public to respond more successfully to the WUI fire threat.

KATE DARGAN is a director of the California Firesafe Council; a member of the National Wildfire Coordinating Group’s (NWCG) Wildland Urban Interface (WUI) Committee, representing the National Association of State Fire Marshals; and a consultant on WUI planning. A California firefighter since 1977, Dargan retired as the state fire marshal. She has been the chair of the State Board of Fire Services, a member of Firescope, and the state co-chair for the development and adoption of the Wildland Urban Interface Building Standards. She fought wildfires across California for 30 years as a California Department of Forestry and Fire Protection (Cal Fire) engine company officer, chief officer, incident command team member, and air tactical group supervisor.


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