Finding Balance in Our Managed Beaches: Policy Recommendations to Mitigate Emergency Sediment Disposal Impacts in Santa Barbara County

Climate change is increasing Santa Barbara County’s vulnerability to sea level rise, coastal erosion, and shifting precipitation patterns. To mitigate impacts and build climate resilience, debris basins have been constructed to intercept sediment transport and protect residents and property during extreme weather events. Sediment accumulated in the basins during emergency debris flows has historically been disposed of at Goleta Beach Park and Carpinteria State Beach to protect eroding coastlines. A comparative review of current permits overseeing basin clearing and deposition activities at the two beach sites was conducted to inform Santa Barbara Channelkeeper (SBCK) on how the increasing frequency of emergency sediment deposition may impact ecological and public health. Based on available data, multivariate logistic regression of fecal indicator bacteria concentrations, streamflow discharge, and precipitation revealed that deposition events increase the likelihood of AB 411 health standard exceedances, with more consistent significance at Goleta Beach. Since bacterial indicator exceedances trigger beach advisories, deposition events reduce beach access and introduce large volumes of foreign, and perhaps contaminated, sediment at beaches. A demographic and activities survey conducted at both beaches indicated that individuals may still visit the beach despite awareness of a water quality advisory. Although current sediment disposal practices are in accordance with existing permits, increasing sediment sampling and alternatives to beach disposal may be needed to reduce associated hazards to human health. These insights can guide future sediment management to minimize long-term ecological harm, protect public health, and ensure equitable access to safe and clean coastal environments.

Acknowledgements

UC Santa Barbara Bren School: Dr. Sarah Anderson, Professor; Dr. Christopher Costello, Distinguished Professor; Nathaniel Grimes, Ph.D Candidate; Dr. Heather Hodges, Lecturer; Dr. Patricia Holden, Professor; Karina Johnston, Ph.D Candidate.

UC Santa Barbara Marine Science Institute: Kyle Emery, Assistant Researcher; Dan Reed, Researcher

Santa Barbara County Environmental Health Services: Stephanie Meza and Jason Johnston

John Campanella

Scott D. Cooper, Research Professor, UC Santa Barbara Ecology, Evolution, and Marine Biology

Shelby Fredrickson, Numeric Solutions

Summer Gray, Associate Professor, UC Santa Barbara Environmental Studies Program

Nate Irwin, Policy Associate, Santa Barbara Channelkeeper

James S. Bower Foundation

Jill Murray, Creeks Supervisor, City of Santa Barbara Sustainability & Resilience

Andrew Raaf, Environmental Manager, Santa Barbara County Flood Control District

Lars Seifert, Deputy Director of Operations, Santa Barbara County Public Health

Alex Simms, Professor, UC Santa Barbara Earth Science

Ian Walker, Professor, UC Santa Barbara Geography

Jonathan Warrick, Research Geologist, U.S. Geological Survey