The Public Utilities Commission adopted new rules Thursday to prevent power lines from sparking wildfires in the aftermath of a series of 2007 fires that destroyed more than 1,500 homes and killed 17 people in Southern California.
Among other things, the new regulations require utilities to increase brush clearance around electrical conductors and to recalculate the weight loads on power poles when new equipment is attached.
Companies that operate cellphone towers and other aerial communication facilities near power lines must regularly inspect them.
Investor-owned utilities will be authorized to turn off power to property owners who block clearance efforts around overhead power lines.
"This is a new tool utilities can use when a landowner refuses access to property for the utility to trim trees," Southern California Edison said in a statement.
In addition, investor-owned utilities in Southern California must create plans to prevent power line fires during weather that creates extreme fire danger, such as the seasonal Santa Ana winds that turn brush tinder-dry.
Electric utilities in Northern California also must create such plans if they determine there is a "credible possibility of extreme fire-weather events," according to a PUC summary.
"Californians are well aware of the yearly threat of wildfires and the devastation they can bring," PUC President Michael R. Peevey said in a statement. "The safety practices we have adopted will provide an additional measure of safety for power lines to lessen the possibility that they may become a trigger for wildfires in the future."
Southern California Edison, which has about 5 million customers in a 50,000-square-mile service area, said it collaborated with the commission to develop the new rules that were hammered out in a long process after dozens of wildfires driven by Santa Ana winds ravaged Southern California in October 2007. The fires collectively scorched more than 780 square miles.
Downed power lines were blamed for sparking some of the worst blazes, especially in Malibu and San Diego County, according to the PUC.
San Diego Gas & Electric Co. didn't acknowledge any wrongdoing but paid the state and the county nearly $39 million in fire compensation.
A call to that utility seeking comment was not immediately returned.