The latest map that shows habitable properties in Montecito, Summerland and Carpinteria at risk of debris flows or flooding from a storm will be released this week by Santa Barbara County officials.
Community members can learn about winter preparedness and preview the updated Interactive Storm Impact Consideration Map that identifies parcels that may be at risk from debris flows or flooding this storm season.
The map will be utilized by local emergency managers to determine the portions of the community that would be evacuated this winter if necessary, according to county officials.
County officials will present a trove of information during a virtual community meeting scheduled for 5:30 p.m. Thursday via Zoom. Click here for more information. At the end of the meeting, the map will be available on the county’s website here.
The Montecito Fire Protection District, in partnership with the Carpinteria-Summerland Fire Protection District and the county Office of Emergency Management, have worked with a private consulting firm to update the risk map following the Jan. 9, 2018, debris flows in Montecito on the fire-denuded hills.
“Generally, scientists tell us that a community is at risk for debris flow between three and seven years following a fire,” Montecito Fire Chief Kevin Taylor said. “That’s the purpose that we continue to update the map.”
The 2017 Thomas Fire blackened more than 281,00 acres in Ventura and Santa Barbara counties, and the inferno was followed three weeks later by the flash flooding and debris flows, which devastated the community, killing 23 people and destroying and damaging hundreds of homes in a matter of minutes.
“Because we are only in the third year following the fire and fourth winter following the fire, we are still at risk,” Taylor said. “Just not as much risk as the previous three winters.”
Taylor noted that a debris flow ravaged Montecito in 1969, the fifth year after the Coyote Fire in 1964.
“We are hesitant to say the community is not at risk,” Taylor said.
The number of parcels on the map considered to be at risk from potential debris flows and flooding decreased notably compared with previous maps.
Officials have identified 445 parcels that are at-risk if there’s a saturating rainfall event followed by a high-intensity, short-duration rainfall during storms, Taylor said. A saturating rainfall event is defined as 8 to 10 inches of rain in less than 48 hours, with a high intensity, short-duration thunderstorm or other rainfall event embedded in it.
There were 517 parcels last storm season and about 1,500 in 2018.
In explaining why there are fewer affected parcels in the updated map, Taylor said it’s because of watershed recovery during the spring growing season, plus mitigation measures in debris basins and improved creek channels.
A group called the Storm Impact Consideration Team will determine the appropriate protective actions — such as an evacuation warning or order — after evaluating the risks, rainfall quantity and duration, and the status of the watershed, creek channels, debris-catching nets and debris basins.
“It would be our hope the community would follow that instruction,” Taylor said.
Kevin Cooper of the Montecito Fire Protection District estimated that 80% to 90% canopy cover occurred in the upper areas of the watershed that was lost in the 2017 Thomas Fire, Taylor said.
“That means it’s not quite robust as pre-fire conditions,” Taylor said, adding that Cooper also advised that the soil in the charred area is recovering, but it’s not at pre-Thomas Fire conditions.
Safety of the community is a top priority and the overriding concern, Taylor said.
“While I’m sure many community members had hoped there would be no debris flow risk this year,” he said, “our community will truly be at risk until the watershed is at 100% back to pre-Thomas Fire conditions, and we continue to hold hope that will occur in five years.”
The updated map will take into account improvements to the Cold Springs debris basin and the continued recovery of the watershed in the charred Thomas Fire areas, according to the county.
“We have a lot of work going on in varying degrees,” said Jon Frye, a Santa Barbara County Flood Control engineering manager.
County Flood Control completed the Cold Springs debris basin expansion project in October, Frye said. The project aims to help increase the ability to capture large amounts of material that come down the hills when it rains, according to the county.
The Cold Springs debris basin is on county-owned land, Frye said.
The project expanded the existing Cold Springs debris basin from about 1.5 acres to about 2.4 acres to increase flood protection for downstream properties, according to planning CEQA documents.
A second project is proposed at the Cold Springs debris basin, along with operational improvements at the San Ysidro and Romero creek debris basin, as well as the Santa Monica debris basin above Carpinteria.
“We have some ideas to make them function a little bit better,” Frye said, adding that the Romero and Santa Monica debris basin projects are slated to begin in 2021, and the Cold Springs and San Ysidro debris basin projects in 2022.
The projects, including construction of a debris basin on Buena Vista Creek, are dependent on grant funding, Frye said. Grant funding came through for the Santa Monica debris basin project, and the county is pursuing grant funds for the other debris basin projects.
The county pursued the upfront design and CEQA documents in advance of receiving grant funds to carry out a series of projects.
For the proposed Buena Vista Creek debris basin, the county isn’t advancing the project design until the grant money is in hand, Frye said.
Construction of a new debris basin near Randall Road and Highway 192 in Montecito is targeted to begin in 2021. A $13.5 million grant from the Federal Emergency Management Agency has been awarded to the county Flood Control District to purchase several properties from homeowners along Randall Road in Montecito and start construction on a proposed debris basin near San Ysidro Creek.
To date, the county has purchased seven of eight Montecito properties for the proposed debris basin.
Eric Boldt, a warning coordination meteorologist with the National Weather Service in Oxnard, told Noozhawk that the risk of debris flows from the Thomas Fire is extremely low.
“The USGS (U.S. Geological Survey) research does not include historical rain rate thresholds for the fourth rainy season on a burn scar, so we will not be issuing a debris flow warning,” Boldt said. “We know that burn scars shed water faster than unburned areas, and that could lead to rapid runoff and flash flooding, especially for areas downstream.”
If rain rates exceed 1.0 to 1.25 inches per hour, the NWS will likely issue a flash flood warning for all areas, whether it’s inside the burn perimeter or outside, Boldt said.
“Our worst-case scenario for flash flooding this season would be several back-to-back storms in a short period (less than seven days) when we might reach soil saturation (water runs off instead of being absorbed) and very heavy rain downpours occur on top of that,” Boldt said.
Boldt said the winter forecast overall calls for a La Niña, which has historically been drier than normal.
“But even during a dry outlook, it only takes one or two storms to cause flood problems if we receive too much rain,” Boldt said, adding that the wettest months on average are January, February and March.
A flash flood warning is issued when a flash flood is imminent or occurring, and it’s possible to experience a flash flood in areas not immediately receiving rain, according to the NWS.
A flash flood is a sudden violent flood that can take from minutes to hours to develop, according to the weather service, and warnings are issued when there is an imminent threat to life and/or property.
Alerts are sent to the community affected by many different avenues, Boldt said.
There are several ways of getting weather warnings, including a NOAA Weather Radio.
The Wireless Emergency Alerts (WEA) system will automatically send messages to smartphones, and radio and television broadcasts are interrupted through the Emergency Alert System (EAS).
Santa Barbara County’s Office of Emergency Management offers emergency notifications via phone or text messages as part of ReadySBC.org. Residents can register for emergency alerts from the county by visiting the ReadySBC.org website.
Boldt said residents also can download free mobile apps such as the Federal Emergency Management Agency, the American Red Cross, or other weather apps send text notifications of warnings.
Kelly Hubbard, director of the county Office of Emergency Management, provided the following preparedness information:
» Register for or update contact information at ReadySBC.org. It’s important that contact information is current.
» Have and update your emergency kit or evacuation “go bag.” Be ready to support yourself and your family within your home, and have a “go bag” in case you need to evacuate.
» The resilience of each community is when they come together to support one another. If you are aware of a neighbor who may need help in a disaster, reach out now (in a COVID-19 safe manner) and see if they may need help if a disaster were to occur.
— Noozhawk staff writer Brooke Holland can be reached at firstname.lastname@example.org. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.