Winter storms raise concerns over possible mudslides, debris flow in the Alisal Fire burn scar area
Rockslides, mudslides and debris flow continue to pose a risk for people living within the area affected by the Alisal Fire, which ignited in Santa Barbara County on October 11 and charred nearly 17,000 acres of vegetation.
When the first winter storm hit the Central Coast last week, residents living within the Alisal Fire area were told to evacuate due to concerns of flooding and debris flow.
The burn scar area received about 3.5 inches of rain, but no major damage was reported.
“We understand this last one didn’t result in a debris flow, and we are very thankful for that," said Walter Rubalcava with the Santa Barbara County Public Works Department. "But as more and more rains come, the absorption of those hillsides is going to become less and less.”
Rubalcava said the concern for potential debris flow in the area will continue for the next three to five years.
“The hillsides are burned," Rubalcava said. "When the rain comes down, the runoff will be greater than normal because there is no vegetation to hold it back, and there will be an increase for debris flow.”
Crews are working now to repair culverts, clear burned vegetation, and address any safety concerns ahead of future storms.
Rubalcava said this week the county also began a rock scaling operation.
“Which is essentially removing the loose rocks that are adjacent to the hillsides below and above the roadway," Rubalcava said. "But we are not going to be able to get all the rock on the hillside, so we are trying to get the most susceptible rocks that are most likely to fall.”
Although the first winter storm didn’t lead to any significant mudslides in the Alisal Fire area, Rubalvaca said residents need to heed any evacuation orders that come down in the future, and not take a chance waiting it out to see what the storm could bring.
“At that point, it’s too late," Rubalcava said. "You can’t outrun a debris flow. It’s essentially a wave of material. In the case of Montecito and other mudslides, it goes straight for structures. We don’t want people to wait that out.”
While safety and repair work along the hillside is currently underway, Caltrans says there will be intermittent lane closures during the week, but it should add no more than ten additional minutes to people’s commute.