Scientific analysis has informed authorities the greatest risk for a debris flow event for the Montecito area would come following what is considered a “saturation rainfall event” rather than a single, high-intensity storm.
This information was shared with the community Thursday night during a meeting hosted by the Santa Barbara County Office of Emergency Management at Montecito Union School. Montecito Fire Protection District Chief Kevin Taylor was one of several speakers who addressed the public as the county unveiled what is now considered the “Storm Impact Consideration Map” that identifies areas that could be at risk if another debris flow were to occur. Officials also discussed vegetation regrowth in the hills above Montecito, the status and possible upgrades to the current debris basins and the weather outlook over the next several months.
As he opened his remarks, Chief Taylor thanked the public for their patience as authorities configured the new map – which was once considered the “Debris Flow Risk Map.”
“We know that many of you would have liked to have it much sooner, but it was very important to us that it be accurate because we recognize the impact that it has on our community’s resiliency,” he said. “Our goal is always to keep the community safe.”
Not yet two years removed from the start of the Thomas Fire that ripped through Ventura and Santa Barbara counties and left the hills barren above Carpinteria, Summerland and Montecito that triggered the deadly Jan. 9, 2018 debris flow, the southern portions of Santa Barbara County will remain at risk for debris flow and flooding. The current risk, however, is considered “much lower” than previous years because the local watersheds have recovered and there is less material that could cause destruction in the local canyons, Chief Taylor said.
“Our risk is significantly less,” he said. “We’re in what we’re calling a transition period. We’re past the highest risk, but not quite at no risk because our community has such a long history of flooding.”
The map released Thursday shows some 517 parcels in Montecito, Summerland and Carpinteria that could be at risk – significantly less than the nearly 1,500 parcels included in last years map.
“We’re at a greater risk for flooding, like we experienced last February, than we are for a substantial debris flow,” Chief Taylor said.
Officials say a “saturation rainfall event” that dumps eight to 10 inches of water in the span of as little as three days could trigger evacuation orders and pose a greater risk than a single, high-intensity rainfall event. A storm impact consideration team has been formed that will examine factors such as the amount of rainfall and duration or the current status of the watersheds that could result in evacuation orders.
“It’s important that we remember that no two storm events are the same and the watershed responds differently to each,” Chief Taylor said. “Flood Control, the fire department and the Office of Emergency Management will be very closely monitoring the impacts throughout the entire storm season to ensure that we have the most up-to-date situational awareness so we make the most appropriate and best decision for the community.
“Because our highest risk is at the tail end of a saturation event, we do not anticipate issuing an order as a result of a single storm event.”
Kevin Cooper, a former biologist and Burned Area Emergency Response team leader for the Los Padres National Forest who analyzed the affected area in the wake of the Thomas Fire, showed photos of upper Cold Springs Canyon over the past two years that showed significant vegetation growth.
Mr. Cooper, who now works for the Montecito Fire Protection District, said that in 2017-2018 there was little to no vegetation near Cold Springs Canyon. Last year, there was about 35 percent of regrowth for higher elevations and up to 50 percent in the hills above the canyon. This year, there is about 80 to 90 percent canopy cover.
“It doesn’t look like that’s going to move quickly,” he said. “Having said that, it’s not back to where it was before the fire and the soil itself has a ways to go before it’s going to recover altogether. It’s got a few more years before it’s going to have all the characteristics of absorption and protection that it has before this area burned. Nonetheless, I think we’ve come a long way and we’re looking at a very different scenario this year.”
Jon Frye, engineering manager for the Santa Barbara County Flood Control District, said that the rainfall experienced this year has resulted in very little, if any, material coming into the debris basins. The same amount of rainfall a year ago brought a lot of material into the basin, he said.
“That right there is evidence that things are going to be a bit different this year – I think in a positive sense,” he said.
The county is pursuing some $38 million worth of projects to improve current basins and add two more despite not having secured the funding. He said that officials are “optimistic” they will receive the funding and the target date to start work is the summer of 2021 or 2022. One of the two new proposed debris basins is located on Randall Road, with the other at Buena Vista Creek at Park Lane.
In addition, the county is working with the Army Corps of Engineers, who is reviewing the current system and examining possible improvements. That study may be available to county officials by January, Mr. Frye said.
Eric Boldt, warning coordination meteorologist with the National Weather Service in Oxnard, told the crowd that the current projections show that Southern California is right in between a La Nina or El Nino event which signifies “below normal rainfall” during winter months.
“That doesn’t mean we won’t have storms, and as you know it only takes one storm to cause our problems so we have to prepare for every storm,” he said. “But overall, throughout the winter season we’re looking at below normal (rainfall).”
When several storms in a row occur, officials will be monitoring the upper watersheds near the mountains that could cause widespread flooding.
“Even if we have saturation and lots of rain going on, that may be fine,” Mr. Boldt said. “When we get those heavier downpours, that’s when we start to see more flash flooding and that’s what we’re going to be watching for.”
Residents are reminded to register for the county’s Aware and Prepare emergency alerts. To learn more or to view the updated map, visit www.readysbc.org.