Until the mid-1800s, most wildfires burned cooler and lower to the ground than the wildfires that burn today. Fires consumed less area and were more frequent, with a given area typically burning every 5 to 15 years. Unlike wildfires today, the majority of historic wildfires were ignited by natural sources such as lightning.
Along with wildfires, historic landscapes in Contra Costa County were maintained through cultural burning by Ohlone, Bay Miwok, and Northern Valley Yokuts tribes. Among many other uses, cultural burning promotes the growth of desired plant species, reduces fuel loads to prevent catastrophic wildfires, and holds important spiritual and ceremonial value for many Indigenous communities. Cultural burning practices have been developed over thousands of years and involve small, frequent, low-intensity fire applied strategically across the landscape. As a result of cultural burning, historic Contra Costa landscapes had many fire-adapted native grasses and wildflowers, and low amounts of fuel reduced the risk of catastrophic wildfire.
Whereas indigenous burning and historical wildfires maintained open landscapes with low amounts of fuel, European colonization and subsequent fire suppression practices have led to a buildup of fuel that along with rising temperatures and periods of drought allow fire to burn intensely and spread rapidly. When European settlers colonized the region in the early 1800s, they viewed fire as a threat to their agriculture, timber industries, and settlements. Settlers forcibly removed Ohlone, Bay Miwok, and Northern Valley Yokuts peoples from their ancestral lands and criminalized cultural burning practices.
In 1910, settlers also imposed aggressive fire suppression policies dictating that all wildfires be put out as soon as possible. Strict fire suppression policies continued until the late 1900s. The graphics below are examples of fire suppression messaging in the United States during the 1900s.
In the 2000s, the negative consequences of long-term fire suppression became apparent. Large, severe wildfires, like the SCU Lightning Complex that burned across 6 counties in the Bay Area in 2020, attest to the limitations of suppression as a fire management strategy.
Today, fire management focuses on balancing ecological needs, public safety, and resource protection. Some local Indigenous communities work to incorporate traditional fire and ecological knowledge into contemporary fire management, but limited access to ancestral lands remains a barrier to reviving Indigenous land stewardship practices. Environmental agencies and organizations, like the CCRCD, work to restore native ecosystems and return beneficial fire to local lands through management strategies such as manual or mechanized fuel reduction, invasive species control, and prescribed burning.
Check out Preparing Your Home for Wildfire to learn about techniques homeowners can use to reduce wildfire impacts to their home, or navigate to Fire as an Ecological Tool to learn how fire itself can be used to fight wildfires.
Wildfire behavior, or the way fire interacts with the landscape, is driven by three components, fuels, weather, and topography. Click on each component to learn about their impact on fire behavior.
Fuels are the flammable materials found in a given area. During a wildfire, smaller fuels dry out more easily and ignite more quickly, while larger fuels retain their moisture longer and take longer to ignite. Fuels can be broken down into categories by their time lags, which represent the time it takes for the fuel to reach ⅔ of its way to equilibrium with the surrounding environment’s moisture conditions: 1-hour fuels, 10-hour fuels, 100-hour fuels, and 1000-hour fuels.
The amount of fuel in an area varies depending on land management techniques and the water content of the surrounding environment. In areas treated with grazing, prescribed fire, or herbicides, or in dry areas, the amount of fuel tends to be lower, whereas wetter and untreated areas tend to have greater amounts of fuel.
Weather characteristics such as wind, temperature, and precipitation influence ignition as well as fire spread. Hot, dry, and windy conditions are most conducive to large and intense fires, as these conditions allow for the fastest ignition times and rapid spread of fire. Strong winds can carry embers far ahead of the main fire and cause new ignitions, called spot fires.
Watch the video below to learn about the hot, dry, and strong Diablo winds unique to the Bay Area, and their impact on the wildfire risk we experience.
Topography impacts fire behavior through fuel amounts and fire spread. Water tends to collect in valleys, while the path of the sun causes north-facing slopes to be shadier and south-facing slopes to experience more direct sunlight. As a result, south-facing slopes are warmer and drier and tend to burn more intensely and rapidly than cooler, more humid north-facing slopes. Fire also travels faster uphill than downhill. The heat produced by the fire rises and is able to “preheat” vegetation above the fire, allowing for faster ignition once the fire spreads.
Skills: Permitting, conservation on agricultural land, illegal dumping prevention.
Fun Fact: Eagle Scout, former member of the University of California Marching Band, aspiring birder, and a Contra Costa native raised in Southern California.
Ben started working with Contra Costa RCD in January 2017 after receiving two Masters degrees from Indiana University in Natural Resource Management and Environmental Policy following undergraduate studies at UC Berkeley. Ben manages the Voluntary Local Program, the EcoStewards Program, and other conservation programs focused on agricultural lands.
Skills: Rangeland ecology and management, fire ecology, California plant identification, data management and analysis.
Fun Fact: Puts buffalo sauce on everything, is passionate about native plant horticulture, and loves tiny plants and fungi.
Zoë grew up in the South Bay Area, where much of her childhood was spent hiking and exploring the local regional parks with her mom. Having grown up in a wildland urban interface community, Zoë is interested in the impact of wildfire on California ecosystems and communities, and aims to both restore historical fire regimes to Bay Area landscapes as well as promote the equitable allocation of fire preparedness, management, and mitigation resources.
Zoë received degrees in Ecology and Psychology from UC Santa Barbara, where she completed an undergraduate thesis exploring how leaf traits can be used to predict fire severity in Southern California forests. Her passion for wildfire ecology and fondness for Bay Area grassland and oak woodland landscapes led her to pursue a master's degree in Rangeland Management at UC Berkeley, where her studies focused on rangeland plant ecology, wildfire and prescribed fire on rangelands, grazing management, and the ways in which people and the environment influence each other. Zoë looks forward to using her ecological knowledge and her passion for environmental justice in her work managing and utilizing fire with the RCD.
Skills: CA Native Plant Identification, Fire Ecology, Environmental Education, Community Outreach, and ARCGIS and other ESRI services.
Fun Fact: I have a Pitbull puppy who my life revolves around, and am a very passionate SF Giants fan as I love baseball, both watching and playing!
Joe has joined the Contra Costa Resource Conservation District following an undergraduate degree in Forestry and Natural Resources with an emphasis in Fire Ecology from Cal Poly San Luis Obispo. As an East Bay native, I grew up exploring all around the wonderful natural areas the Bay Area has to offer and I am extremely excited to begin serving my local communities. Before joining the team, I served a separate Americorp term at a local fire department which gave me a great insight into the world of vegetation management, community education, and community engagement. I'm very eager to bring my knowledge and skills to the team, and look forward to educating, supporting, and implementing positive change in and around my home.