Facing a possible super El Niño, Ventura County officials have identified potential hot spots – from burn scars to hard hit canyon roads – and work needed before what could be severe winter storms.
The latest forecast showed El Niño continuing to strengthen, with a more than 90% chance of a very strong event. The warmer waters near the equator can mean a wet winter in Southern California. It doesn't guarantee more storms, but experts say a stronger pattern generally tilts the odds.
That may mean more storms and above-normal rainfall as well as high ocean waves that can cause damage along the coast. County agencies briefed the Board of Supervisors on Oct. 6, including on recent efforts, from placing thousands of sandbags around the county to emptying
debris basins.
"We have a lot of numbers flying around regarding the possibility of this event and what it might bring," said Chuck Scherrei, deputy chief of the Ventura County Fire Department. "We know that it is going to bring something. We're just not sure what."
In the meantime, vegetation reached critically dry levels before the latest heat wave. When that happens, fires can become more difficult to suppress.
"We're either going to get rain first or we're going to get wind first," Scherrei said, during the Oct. 6 meeting.
If Santa Ana winds show up first, that could mean more fires and additional threats of post-fire debris flows.
How will recent burn scars hold up to winter storms?
During intense rainfall, burned slopes become vulnerable to flash floods and debris flows, a threat that can last for years. Without vegetation, there can be little to hold the dirt in place. When hills erode, the runoff can carry rocks, sediment, burned debris and vegetation downstream.
Just one storm can cause problems after a wildfire, depending on how quickly the rain falls and other factors. In general, experts say a half-inch of rain per hour could trigger flash floods and debris flows after a fire.
Agencies set a slightly higher threshold of 0.6 of an inch of rain for spots burned in this year's Sandy Fire in the Simi Valley area. That's when officials say they could see problems start.
"We will need to monitor that area very closely," said Patrick Maynard, director of the Ventura County Sheriff's Office of Emergency Services.
A similar threshold was in place for areas burned in the Mountain Fire in 2024. The blaze that started near Somis burned 31 square miles and destroyed 243 structures, many in the hills above Camarillo. Two years later, agencies cited factors from vegetation recovery to soil type that showed conditions had improved.
The threshold will return to an inch per hour – a rainfall rate that officials say could trigger a debris flow in any area countywide, regardless of a previous fire.
What spots are vulnerable to El Niño storms?
Maynard and others said there were still a lot of unknowns, including whether more severe storms will drench the county or be a no-show.
"We're kind of walking this tightrope in that we don't want to scare people, because we don't know what's coming," county Supervisor Matt LaVere said. "But we also don't want to get caught flat-footed."
Departments formed task forces to prepare for possible winter storms, from one focused on response to another looking at finance and recovery. Among efforts underway, public works officials said overtime was authorized to catch up on deferred maintenance and other preparation efforts. Crews have worked to clear stormwater channels and debris basins, according to the agency.
Concerns included communities hard hit in prior years, from La Conchita, off Highway 101 north of Ventura, to Matilija Canyon Road. The windy, mountain road north of Ojai was significantly damaged in recent winters and remains vulnerable in spots, officials said.
"We're talking about some contingency plans in the event that we lose access, which we commonly do in that area," Maynard said of the remote spot.
To sign up for emergency alerts in Ventura County, go to readyventuracounty.org/vc-alert.
Cheri Carlson covers the environment and county government for the Ventura County Star. Reach her at cheri.carlson@vcstar.com.
This article originally appeared on Ventura County Star: Facing a super El Niño, these Ventura County spots may be vulnerable
