Can shutting off power prevent wildfires in California during windy weather?

In California there is a recognised danger of powerlines sparking wildfires when it is extremely windy. Given this state of affairs, utilities in the state are responding with proactive, if drastic, measures – shutting off the power.

Last week, the residents of the area controlled by Southern California Edison spent around 33 hours without electricity because of the high winds. This was a measure that was supposed to prevent the outbreak of a wildfire.

The same thing happened to people living in a mountainous area of southeast San Diego. This occurred while huge portions of Southern California was under red flag alert – meaning that there was a high risk of wildfires because of the adverse weather. A spokesperson from San Diego Gas & Electric (SDG&E) explained the importance of de-energising as a tool to protect communities at risk from being affected by wildfires.

This dramatic step has come into play as a result of one of the worst wildfire seasons in California’s history. Recently, firefighters have had to battle against the immense Thomas fire that spread through the counties of Ventura and Santa Barbara.

William Stewart, a wildfire expert and co-director of University of California-Berkeley's Center for Fire Research and Outreach, commented on the issue. He connected windy days with big fires and noted that power lines are one of the sources of ignition.

And, these measures haven’t been implemented a moment too soon. It is estimated that this year alone wildfires in California have burned through roughly 1.36 million acres – an area almost as big as the state of Delaware. It has reduced entire neighbourhoods to ashes and killed crops and forests. The vegetation in this part of the country is generally very dry due to the lack of rain – this is why it burns so easily.

In 2016, hefty rainfall put an end to the drought that plagued California for some time. However, the particularly thick grass growth that came as a result has now acted as further fuel for potential wildfires. More fuel comes by way of dead trees that have suffered from lack of water and beetle infestation.

As it is still unclear what caused the Thomas fire, the investigation continues. "All the major fires in Southern California are still under investigation," said Cal Fire's McLean. "It's going to be an ongoing investigation, and it does take time."

In the meantime, Southern California Edison might come under investigation as the mission to determine the cause of the Thomas fire continues. At least one death has been linked to the fire so far. The fire also destroyed over 900 structures and is recorded as being the fifth biggest wildfire in modern history.

The preventative shutoff measure is driven by a sense of public safety in the hopes of preventing any deadly disasters, which have been made more likely by California allowing people to build homes near wild-fire prone areas. The measure will also protect utilities from being liable for negligence, among other things, when these fires do occur.