Sep. 7--With wildfires churning through wilderness near Los Angeles and Santa Ana wind season lurking around the corner, San Diego Gas & Electric Co. is hoping state regulators this week will greenlight its plan to turn off electricity during periods of peak fire danger.

Stung by state investigations that blamed its wires for three October 2007 infernos and having paid out $740 million in settlements in connection with those blazes, San Diego County's primary electricity provider is looking for ways to prevent power lines from starting more fires and to limit its liability.

The big utility, which serves 3.4 million people, has been replacing wooden poles with sturdy steel ones, increasing space between wires, putting wires underground and disabling switches that automatically turn power back on when wires trip off in fire-prone rural areas.

The company also wants to be able to cut power to as many as 110,000 people spread from De Luz to Alpine when humidity, wind speeds and plant moisture levels reach certain thresholds in Santa Ana episodes.

And the company wants to be shielded from potential lawsuits arising from damage caused by a loss of power.

While most measures are widely supported, the power shutoff component of its fire-prevention initiative is controversial. It is opposed by residents of affected communities, including De Luz, Fallbrook, Pala, Pauma Valley, Valley Center, Ramona, Julian and outlying areas of Escondido and Poway.

The plan also is opposed by water districts, advocates for disabled people, a consumer group and administrators for 65 backcountry schools.

Opponents contend that turning off power would make matters worse if a fire were to start for some other reason because telephones, televisions, computers, life support equipment, traffic signals and street lights would be disabled.

They say many people would not receive warnings to evacuate and evacuations would become chaotic.

"Most troubling of all," said Melissa Kasnitz, attorney for Disability Rights Advocates of Berkeley, "SDG&E's proposal could result in serious injury or death if life-support equipment such as respirators or dialysis machines exhaust available backup power options during a prolonged power outage."

The California Public Utilities Commission will try to sort through the issues this week when it gathers Thursday in San Francisco to decide the plan's fate.

Mike Niggli, SDG&E's chief operating officer, said in an interview last week that the raging wildfires up north underscore the threat facing San Diego County as autumn approaches, and the need to proactively disable power lines when there is a chance they will ignite fires.

"Hopefully it will not be, but we are at risk of having a potentially very severe fire season," Niggli said.

The worst of the Los Angeles-area blazes, the Station fire, has torched about 150,000 acres and ranks as the 10th biggest wildfire in California history. And the blaze did not have a gale-force Santa Ana wind behind it.

Historically, Santa Anas begin to blow in October.

According to the California Department of Forestry and Fire Protection, or CalFire, four of the state's 20 biggest wildfires were sparked by power lines, and two of those were in San Diego County. One was the 198,000-acre Witch Creek fire of 2007, which was the fourth largest. The other was the 1970 Laguna fire, which at 175,000 acres was sixth largest overall.

Had SDG&E's shutoff plan been in place a few years ago, power still would have been on when the Witch Creek fire ignited on a ranch midway between Ramona and Santa Ysabel.