If you live in a place that's prone to , there's one phrase you always listen for: "the fire is (x) percent contained." A 95 percent contained fire sounds a lot less scary than a 25 percent contained fire, and if you're , that number might make all the difference.
But containment doesn't necessarily mean a fire isn't still raging. Rather than describing how much of the fire has been put out or beaten back, containment actually refers to the perimeter that firefighters create around the fire to keep it from spreading.
Take California's , for example, which as of this writing is at . That means that 60 percent of the fire is surrounded by containment lines 鈥� any physical barrier that stops the fire from passing a certain point. Those lines can be trenches, natural barriers like rivers, or even already-burned patches of land. Most often, the containment line is a shallow, firefighters dig into the dirt.
According to ,
Containment simply means that a line will have been dug all the way around the perimeter of the fire, but the blaze itself is expected to still burn within it for weeks, if not months.
If a fire is 100 percent contained, that means firefighters were able to complete a perimeter around it and stop it from spreading. It doesn't mean the fire stops burning.
That poses another problem 鈥� while it's relatively rare, fires can sometimes jump containment lines. Extreme weather conditions can push fires over containment lines, undoing firefighters' progress and putting more land at risk.
That possibility hangs over the Thomas Fire in California, which has been stoked by the Santa Ana winds. Containment levels there have already dropped once due to the winds, from
Once a fire is contained, firefighters enter the "control" phase 鈥� the kind of thing people might typically associate with firefighting. According to ,
Controlling a fire means ensuring that the fire can't spread or cross the containment line. That means putting up barriers, removing or burning any fuel that could help the fire spread, and cooling any hot spots 鈥� those are especially active parts of the fire that could suddenly jump.
Currently, in a state that's seen the in 2017, California's Thomas Fire is second only to the . Full containment might not come until 鈥� and even then, it won't be over yet.
Benjamin Purper is a National Desk intern.
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