City officials are considering ways to mitigate the risk of a debris flow near the Mesa after last week’s Loma Fire scorched around nine acres of land near Loma Alta Drive.
Last Thursday’s brush fire burned a significant portion of the hillside near TV Hill, and officials say the charred vegetation and burned soil increases the risk for mudslides in the area if the region gets rain any time soon.
“The hillside is going to pose a challenge to us,” Fire Chief Chris Mailes said during a Santa Barbara City Council meeting Tuesday. “It’s a very steep slope, and if we do get a large amount of rain, we could end up having some debris flow from it.”
The potential for a debris flow caused officials to reminisce on the Thomas Fire of 2017, which ultimately led to the devastating Montecito mudslides just three weeks after the area burned. In anticipation of a possible debris flow, city engineers are planning to meet today and Friday at the site of the Loma Fire to discuss mitigation strategies, Kevin Corbett, a Santa Barbara City Fire engineer, told the News-Press.
“The potential for (a debris flow) definitely exists, and the Fire Department will respond in case that happens, but as far as preventions, the city engineers are working on a plan to mitigate that,” Mr. Corbett said.
Edward Keller, a UCSB professor and expert in Earth Surface Processes, assessed the site of the fire earlier this week to make an estimate on the amount of sediment produced from the burn. The fire caused a fair amount of ash to accumulate on the surface and plugged up holes in the soil, which can lead to “an increase in runoff and sediment that is several times greater than if you hadn’t had rainfall,” Dr. Keller told the News-Press.
To protect structures on Loma Alta Drive and the surrounding area, Dr. Keller suggests implementing slope erosion control measures, such as bails of hay or rolled up straw, to catch any loose sediment when it falls. Because there are not many large boulders on the slope, Dr. Keller said a mudslide would be the more likely outcome if rain hits the area as opposed to a debris flow.
“Debris flows are pretty much out of the question,” he said.