By Lexi Journey, Natural and Working Lands Program Manager, Rincon Consultants
Wildfires are prevalent in San Luis Obispo County. Within the last 75 years, wildfires have burned more than 300,000 acres (7,500 square miles) and today San Luis Obispo County averages more than 300 wildfires per year. Examples of large and destructive wildfires in San Luis Obispo County include the 1960 Weferling Fire (51,451 acres), 1950 Pilitas Fires (30,100 acres), 1985 Las Pilitas Fire (84,271 acres), the 1989 Chispa Fire (9,750 acres), the 1994 Highway 41 Fire (50,729 acres), 1996 Highway 58 Fire (106,969 acres and the largest fire in San Luis Obispo County’s recorded history), 1997 Logan Fire (49,4990 acres), and most recently the 2016 Chimney Fire (46,233 acres). All these fires burned within the wildland urban interface (WUI). These wildfires resulted in more than the loss of homes and infrastructure, they also resulted in the loss of lives. Since 1931, there have been fourteen deaths related to wildfires in San Luis Obispo County, all 14 were firefighters.
There are currently multiple efforts underway to develop plans related to evaluating and reducing wildfire risk and mitigating consequences in San Luis Obispo County. These plans have typically been based on jurisdictional or land use planning area boundaries. The intent is to guide hazardous fuels reduction, defensible space, home hardening, prescribed burning, ecological restoration, and more. Because they are based on artificial (and changeable) boundaries, these plans vary depending on each plan’s objectives. No single plan has been developed for the whole county based on an established, consistent format. This has resulted in decentralized project development that ignores the fact that wildfires frequently cross jurisdictional boundaries. While many of these efforts have been successful, there is value and efficiency gained in developing consistent planning areas throughout the county.
Therefore, through a California Climate Investment grant from CAL FIRE, the San Luis Obispo County Community Fire Safe Council (SLO FSC) has engaged a variety of partners to establish the San Luis Obispo County Fireshed Report and accompanying online Fireshed Dashboard.
The SLO FSC is managed by Dan Turner, retired fire chief and co-founder of the Cal Poly San Luis Obispo Wildland-Urban Interface Fire Institute who said, “While it is seemingly intuitive to utilize jurisdictional lines and land use planning boundaries for firesheds, the Fireshed approach visualizes the county in pre-colonial days when no artificial boundaries existed, only natural barriers to fire spread. This method recognizes the natural boundaries and microclimates that affect fire behavior.”
These firesheds are defined by areas of common geography and comprehensive wildfire behavior characteristic drivers (especially wind and ocean influence) where socioeconomic and ecological concerns regarding wildfire overlap. The methodology recognizes, but does not rely on, jurisdictional boundaries. It is instead based upon an understanding of historical fire spread patterns.
Expert knowledge of historical wildfire behavior was used to identify the appropriate criteria to accurately distinguish each unit's boundaries. This resulted in natural barriers to fire, such as mountain ranges, valleys, roads, ridgelines, and developed areas, to shape the natural borders between the different firesheds.
Examples of partners that were critical in the development of the firesheds included local fire departments, CAL FIRE, the San Luis Obispo County Office of Emergency Services, California Polytechnic State University - San Luis Obispo, and a former United States Forest Service biologist.
These partners teamed with the SLO FSC to delineate firesheds using a diverse set of metrics and data to categorize wildfire risk, as well as risk of wildfire spreading. These factors include topography, elevation, vegetation, microclimates, soil types, hydrology, wildland urban interface, wildfire risk assessment modeling, ignition history, roadways, fuels reduction, land ownership, ignition modeling, infrastructure, structure characterization, and evacuation routes. The resulting firesheds that were developed allow for the characterization of specific fire and community-related factors to promote consistency in the delineation of focused wildfire planning in San Luis Obispo County.
Through the assimilation of available Geographic Information Systems (GIS) data into a simple user interface, decision makers can use the Fireshed Report and Fireshed Dashboard to provide key information about dynamic factors affecting wildfire and management. There is increased long term value and efficiency in coordinating across planning areas for maximum collaboration, resource efficiency, data sharing, and analysis for use by stakeholder agencies to perform hazard and risk assessment, mitigation measures, ecological restoration, and emergency operations and recovery. This resource provides project planners and those seeking grant funding with a consistent platform on which to base their funding and permit applications and plans. Funding organizations and the public at large will benefit from this established standard with a better understanding of the larger strategic approach that a single project can relate to within this planning framework.
Consistency in wildfire planning across the county will improve collaboration, data sharing, data analysis, and education associated with the many wildfire planning and mitigation projects that are currently under way or being planned for in the future. A focused effort developed in concert with established standards will result in projects that complement one another and magnify benefits countywide. The Fireshed Report and accompanying online Fireshed Dashboard will result in a comprehensive source for reliable, consistent, and up-to-date data for project development and enable stakeholder agencies to plan for wildfires more effectively in San Luis Obispo County.