The recent Camp fire in California has been declared the deadliest in the state’s history. The devastation is yet another example of the collision of climate-related risks and the human-built environment. Climate change isn’t the singular cause of the Camp, Hill and Woosley fires; however, it has amplified environmental factors (including warmer and dried-out soils) in creating a longer fire season that sets the stage for increased risk. Growth and development have met these environmental factors at what experts call the “wildland-urban interface.”
The wildland-urban interface (WUI) is defined as the intersection of undeveloped natural land and human-built environment. Here, homes, developments and public infrastructure meet or intermingle with undeveloped, environmentally sensitive areas. It’s created when people migrate farther and farther into “natural” areas in pursuit of privacy, natural aesthetics, recreational opportunities and more affordable housing. Where there are people, housing follows. And where there is housing, other critical infrastructures and development are needed.
The WUI is a key factor in identifying the potential for wildfire disaster losses ― California alone has more 4.5 million homes located within the WUI. Growth alone is not necessarily a problem, but poorly planned and unmanaged growth ― particularly in hazardous or risky areas ― can result in catastrophe. Low-density development, such as individual homes, significantly increase the fire-fighting cost, for example. California is not alone in its need to advance policies related to the link between growth management, hazard mitigation and land use; most states have room for improvement (and not just limited to fire ― floods, also).
“Growth alone is not necessarily a problem, but poorly planned and unmanaged growth ― particularly in hazardous or risky areas ― can result in catastrophe.”
Physical vulnerability in a natural hazards context is usually characterized by things like location and proximity of the human-built environment to a hazardous threat. And the western region of the U.S. is historically volatile. This is especially true in California, where fire is a part of the natural ecosystem; a variety of vegetation have adapted to fire, and some reproduce only after a large fire. But when physical risk meets the social environment (including homes and other infrastructure), the human-built environment can also be literal fuel for naturally occurring fires.
Both windblown embers (small pieces of burning wood) and the flame front (the line of fire moving with the wind and topography) also cause concern in the wildland-urban interface. Because embers, not just direct flame, can destroy structures. And embers may precede the flaming fire front, carried by winds and distributing burning brands or embers across long distances. These embers fall ― or are wind-driven into vegetation around structures or into air vents ― and can go undetected for some time.
Urban and regional planners can help communities achieve smart growth in smarter places. More specifically, planners focused on hazard mitigation can help communities think about growth and development in the context of hazard risks and the vulnerabilities associated with those risks. Planners can also support communities in developing a hazard mitigation plan that includes long-term strategies for protecting people and property from future hazard events.
“Urban and regional planners can help communities achieve smart growth in smarter places.”
Research has shown federal policies make little difference in community land-use actions. State policy, on the other hand, exerts a strong influence. Therefore, mitigation and adaptation strategies have to be locally grounded and locally governed. Zoning plays a role in planning as well and most often is carried out at the local municipal level; it regulates the type, location, bulk and density of development and continues to be based on the Standard State Zoning Enabling Act of 1924.
Some of the nation’s earliest zoning laws were motivated by fire. Setback zoning laws were a form of hazard mitigation in which houses were required to have a certain amount of space between them to prevent fires jumping from home to home. In fact, just a few years before SZEA was issued, the city of New York enacted a zoning resolution related to buildings, congestion, living conditions and to reduce the risks of fire. Zoning on a larger scale can be used as a planning tool to regulate growth and establish buffers between hazards (e.g., fire-prone wildlands) and human development.
The concept of adaptation ― modifying building practices in consideration of climate change and changing environmental conditions ― has grown in popularity over the last two decades. And a community’s wildfire adaptation often sits at the household level. Take California’s WUI building codes, for example. Specifically, the law requires that homeowners reduce vegetation 100 feet (or the property line) around their buildings to create a defensible space for firefighters and to protect their homes from wildfires. Building codes, which include ignition-resistant standards, are thought to protect buildings from being ignited by flying embers.
Of course, a final tool in reducing risk is to incentivize development in lower-risk areas. Higher-density development in urban areas reduces the cost of fire protection and often reduces overall fire risk. Policymakers and planners should develop zoning and land-use policies that guide development away from the riskiest areas.
“Some of the nation’s earliest zoning laws were motivated by fire.”
Communities have all of these planning tools at their disposal, but more inclusive and innovative practices are needed to improve wildfire resilience. This means mitigating fire when possible and, when exposure is inevitable, bouncing back ― and bouncing back in such a way that future buildings, structures and systems are more adapted. Communities across the country (including those in California) have already begun this process, but we believe many necessary household- and community-level adaptations have yet to be identified.
Planners must increasingly provide an opportunity for community members to participate in the development process, not just to voice concerns, but to exchange ideas and practices and find ways to actually implement adaptation strategies. Communities are more resilient when everyone has an opportunity to participate and share their vision for future growth. And as the recent wildfires in California have shown, we all have a stake in this.
Marccus D. Hendricks, Ph.D., MPH, is an assistant professor of urban studies and planning in the School of Architecture, Planning and Preservation, and a research affiliate with the Center for Disaster Resilience at the University of Maryland. His research interests include infrastructure planning and management, hazard mitigation, and sustainable development.
William Mobley, Ph.D., is a postdoctoral researcher with the Center for Texas Beaches at Texas A&M Galveston. His research focuses on hazard mitigation in the urban environment. Specifically focusing on wildfire and urban flooding, he explores how changing community development patterns can reduce hazard risk.