structural ANALYSIS
Defining the Role of the Structural Engineer in Developing Fire-adaptive Communities
Reducing the susceptibility of structures and critical infrastructure to wildfire damage requires multi-sector and multi-pronged solutions. By Erica Fischer and Negar Elhami Khorasani
T
he wildland-urban interface (WUI) is where structures or other climate, the current approach to managing the fire hazard is neither human development interfaces or intermixes with wildland veg- sufficient nor sustainable. The result is what we see today: fires are etation. Today, many WUI communities are being threatened by fire increasing in intensity and frequency. or consumed by it. To understand how this predicament came to be When fire intrudes within a community, and homes ignite, they will with respect to wildfire impacts on communities, the policies and release substantially more energy than vegetation and will burn for mitigation practices of the past must be understood. At the begin- much longer than vegetation. The danger of this is that in many of the ning of the 20th century, the U.S. enacted recent major fires we have witnessed (e.g., policies that stipulated fires should be put out 2018 Camp Fire, 2021 Marshall Fire, and immediately within the wildland to protect 2023 Maui Fire), high winds occurred simulStructural engineers can contribute timber crops. These policies were in reaction taneously with the fire. Therefore, embers or to developing methods and to the Big Blowup of 1910, which consisted firebrands generated by the burning vegetasolutions for fire resistance design of over 1,700 fires across Idaho, Montana, and tion and structures can travel several miles Washington, burning more than three million (in the 2021 Bootleg Fire in Oregon, embers and construction of critical facilities, acres of federal and private land and killing at traveled 5 miles), igniting other parts of the reducing the recovery time after a least 85 people. These fires were estimated to wildfire event, quantifying wildfire risk community. During a wildfire, structures are have destroyed about 7.5 billion board feet not only an asset to protect but also the fuel for communities, and adaptation and for the fire within the community. Structures of timber. mitigation to create resilience against can intensify the fire demand itself substanHowever, scientists concluded in the middle extreme wildfire events. of the 20th century that fires were actually tially. Destructive fires lead to significant beneficial to our landscape and that putting losses, damaging homes and critical infrastrucout all fires was detrimental to many plants ture such as hospitals, schools, water networks, and animals. It took the U.S. until the end of transportation networks, etc. As structural the 20th century to roll back these policies. Meanwhile, communi- engineers, we understand the resulting societal and economic impacts ties were growing and developing within high-risk and fire-prone of damage to such infrastructure systems, given the existing research regions. Today, fires are still suppressed, especially if they threaten and established practices for other hazards. people and communities. However, the expansion of communities Therefore, a future solution must be a multi-prong approach that into the wildland, together with the effects of climate change, has engages civil engineers such that land management agencies are not the led to destructive wildfires in recent years. To combat this threat to communities, the U.S. Forest Service and other land management agencies have been working to manage fires within the wildlands. The U.S. Department of Agriculture and Interior developed the National Fire Plan after the devastating destruction of communities due to wildfires in 2000. In 2001, a 10-year Comprehensive Strategy Plan was developed to reduce wildfire risks to communities and the environment. This effort led to the Healthy Forests Restoration Act of 2003, which developed a framework for Community Wildfire Protection Plans. In May 2016, the White House issued an executive order (EO 13728) for enhanced wildfire risk mitigation in the WUI. Despite all existing efforts, due to the proximity of communities to these wildlands and the changing Figure 1. Timeline of wildfire suppression policies within the 20th century.
22 STRUCTURE magazine