On 9 January 2018, post-fire triggered debris flows devastated the community of Montecito located on the piedmont of the Santa Ynez Mountains in southern Santa Barbara County. Debris flow impacts resulted in 23 fatalities, over 500 homes destroyed or damaged, and closure of the main transportation corridor, U.S. Route 101 for 12 days. The Partnership for Resilient Communities (TPRC) funded this study to construct a historical inventory of previous flood events that included physical evidence of the relative severity of damages, inundation depths of previous debris flows, and the various types of flood events (debris flows or debris laden floods) for the Communities of Montecito, Carpinteria, and Santa Barbara.
This study necessarily placed emphasis on the historicity of destructive flood events that could reasonably be assumed to have resulted in the mass mobilization of debris flows within given watersheds following sustained and intense precipitation. Noting qualitative variables was of the utmost importance. These include factors such as antecedent rainfall prior to an event, time of the year, whether the event was preceded by brush fires, and how many months or years since the last fire occurred. These data improve our understanding of the magnitude of such events, watersheds affected, and the frequency of post-fire events. Our long-term goal is to reduce the debris flow hazards by identifying sites along the principal watercourses most suitable for debris catchment basins.
Dr. Larry Gurrola obtained his B.S. and M.S. in Geology from San Diego State University where he studied paleo earthquakes of a splay of the San Andreas fault in southern California. He continued at UC Santa Barbara with Ph.D. research on the active tectonics and the Quaternary geology of the Santa Barbara coastal plain. His publications include establishing the Quaternary chronology and uplift rates of the Santa Barbara coastal plain, fault activity, and landslide hazards. A registered Professional Geologist and Certified Engineering Geologist, he consults in southern and northern California, and leads the debris flow mitigation study funded by The Partnership for Resilient Communities.
Dr. Gurrola served as past Treasurer and Vice-President for the Coast Geologic Society in Ventura and has presented numerous talks on earthquake and landslide hazards to local schools, government agencies, first responders, and other regional geologic societies. He is a member of the Association of Environmental and Engineering Geologists, Geologic Society of America, American Society of Civil Engineers, Pacific Section Society of Sedimentary Geology, and Coast Geologic Society, Ventura Chapter. He has participated as a volunteer member of the 2018 Technical Advisory Board for the American Institute of Architects for the Montecito Debris Flow Recovery Committee.