CAMP PENDLETON, Calif. — Firefighters continue to make progress on the Henderson Fire, which has burned more than 3,226 acres across Camp Pendleton since it started Thursday. As of Sunday, the fire was 85% contained.
The wildfire quickly spread across dry vegetation, fueled by strong Santa Ana winds, and at one point burned dangerously close to Interstate 5.
Despite recent rainfall from Tropical Storm Rachel, fire officials say conditions on the ground remained dry enough to support rapid fire growth.
"We've received several inches of rain in certain parts of the county, but it takes time for those plants and that grass to absorb that water," said Cal Fire Captain Mike Cornette. "Our fuel moisture levels are still extremely low, so we will still see extreme fire growth in certain situations, especially when fires are responding to the wind and topography."
Camp Pendleton received more than two inches of rain during last weekend's storm, but officials said it was not enough to significantly increase moisture levels in the area's vegetation.
While firefighters continue working to secure the perimeter and prevent additional growth, experts say the fire has created another concern ahead of what forecasters expect to be a wet winter.
Thousands of acres of burned hillside are now left vulnerable to erosion and mudslides. Geologists warn that the loss of vegetation could increase the risk of dangerous debris flows if heavy rain arrives in the coming months.
This year's weather pattern is being called a 'Super El Niño,' meaning excessive rainfall is expected over the next few months.
Dr. Pat Abbott, Geology Professor Emeritus at San Diego State University, said vegetation plays a critical role in stabilizing hillsides and preventing soil from washing away during storms.
"The plants are dead. The roots aren't there to hold the soil," Abbott explained. "We've seen examples where heavy rains following a big wildfire have led to disastrous mudflows, causing damage and even deaths."
He pointed to the deadly Montecito mudslides of 2018 as a worst-case scenario.
"Heavy rains on those fire-burned slopes sent mudflows across the highway and into homes, actually killing 23 people," Abbott said. "I hate to even think of things that bad, but when you ask how bad it could get, that's the worst example I'm aware of in California."
Local agencies have spent months preparing for the possibility of a strong El Niño season by clearing storm drains, reinforcing vulnerable slopes and stabilizing coastal bluffs. Experts say limiting the size of burn scars is another important step in reducing future flood and mudslide risks.
According to Cal Fire's latest update, crews spent Sunday securing the fire's perimeter and working to prevent any additional spread.
The cause of the Henderson Fire remains under investigation.
