Butte County is set to unveil a new siren warning aimed at alerting residents to evacuate during emergencies, nearly nine months after 85 people in the county died in the devastating Camp Fire.

The European-style siren has been installed in the county's patrol vehicles, Butte County Sheriff Kory Honea said in an interview with KQED News. He said his department has developed a policy that calls for using it when deputies don't have the ability to go door to door to warn citizens of an imminent threat.

"We will go through neighborhoods sounding that particular siren. That's the only time we will use it. It means there's an evacuation in effect in that area," Honea said, adding that the tone is different from emergency sirens normally heard in the United States, which will in theory make it standout in an evacuation.

He said while having uniformed law enforcement knock on doors is the most effective way to notify people, it's unrealistic during a major disaster.

"There's no jurisdiction that has a sufficient number of resources," Honea said, "especially when you're dealing with a no-notice event like the Camp Fire."