There are 16 wildfires burning in California. One of the largest fires is the Carr Fire near Redding. The Carr Fire has been burning for more than three weeks and as of mid-August, it has not been fully contained. It has destroyed more than 1,000 homes and over 200,000 acres, making it one of the largest wildfires in California’s history.
To identify the areas most at-risk for further damage, we looked at the footprint of the burn zone and the location of the most recent infrared fire sensor data (Visible Infrared Imaging Radiometer Suite or VIIRS). The map below shows the burn zone in red and the locations of active fires in yellow (based on data as of 8/16/2018).
Based on the burn zone and locations of active fires we identified the block groups most at risk if the fire were to expand, i.e., those block groups that are closest to the burn zone and active fire sensors. We found four block groups that are at the highest risk for continued fire damage; They are shown in gray on the map.
Three of the four block groups exhibit extremely high vacancy rates (52%, 36%, and 36%). Comparatively, the US vacancy rate is around 10% and the California vacancy rate is around 5%.
We found that there are nearly 800 vacant housing units located in the four blocks. The significant number of vacant homes could be a cause for concern.
Studies have shown that homes with regular maintenance are more likely to survive a fire. Vacant properties are often poorly maintained and tend to have flammable spots such as tall grass, gutters filled with pine needles, or untrimmed trees that can fuel a fire. There may also be a collection of waste, rubbish, and trash, and other potentially combustible materials.
A vacant property that isn’t necessarily in the fire path could more easily catch fire from a piece of burning debris blown far from a wildfire by the wind. Bits of burning debris can engulf an entire home in flames if they collect in flammable spots such as tall grass near the house.
The surrounding non-vacant properties are also at risk when vacant residential buildings catch fire. It typically takes longer for vacant residential building fires to be detected. According to the U.S. Fire Administration National Fire Data Center, of vacant residential building fires 11 percent extended beyond the building to adjacent properties. Therefore, the property loss is greater.
Additionally, vacant homes often serve as a site for illegal activity or are used by squatters as temporary shelters. A major concern when a vacant building catches on fire is that little is known about the building’s overall condition. Many buildings are in disrepair and can be missing staircases or portions of floors. If individuals are known to use the vacant building as a residence, the unknown condition of the building and the unknown number of people using the building as a shelter can put the firefighters’ lives in danger when they enter the building to attempt a rescue during a fire.