Evaluating the Equity and Efficacy of Los Angeles County's Stormwater Capture Projects
Urban watersheds face ongoing challenges from urban runoffpollution. Stormwater capture projects are touted for their multi-benefit outcomes, but there is a gap in the data examining their potential pollution reduction impacts on fecal indicator bacteria (FIB) and associated water quality at beaches. Our group analyzed ten years of FIB data collected at Los Angeles County beaches from 2014-2024, and found support for the positive relationship between FIB concentrations and precipitation which has been previously described in literature. We investigated a decade of stormwater capture project implementation within Los Angeles County and analyzed the equity of project distribution and impacts of project count and cumulative treatment volume on bacterial water quality. Due to insufficient FIB data, our analysis could not support beach-level conclusions about the efficacy of upstream stormwater capture projects. However, our literature review revealed strong evidence for localized impacts. Using information derived from our literature review and conversations with stormwater practitioners in Los Angeles County, we used ArcGIS to generate recommendations for land parcels well-suited to hosting stormwater capture projects. We recommended over 100 parks and over 400 schools. We conducted preliminary hydrologic modeling of pollutant reduction on the 20 largest recommended sites to provide a starting point for future project proposals. These recommendations, water quality analysis, and database of stormwater capture projects are available to the public through our interactive Shiny App.
Acknowledgements
UC Santa Barbara Bren School: Dr. Naomi Tague, Professor; Dr. Arturo Keller, Distinguished Professor; Trace Martin, PhD Student; Dr. Patricia Holden, Professor; Dr. Christopher Jerde, Lecturer and Associate Research at UCSB Marine Science Institute
Heal the Bay: Annelisa Moe, Associate Director of Science & Policy, Water Quality; Naomi Meurice, Water Quality Data Specialist
Los Angeles Regional Water Quality Control Board: Jenny Newman, Assistant Executive Officer
City of Los Angeles: Dr. Majid Sadeghi, Environmental Engineer
County of Los Angeles Department of Public Works: Diego Carrizo, Civil Engineering Assistant; Rafael Piamonte, Civil Engineer; Alexander Iglesias Rosales, Associate Civil Engineer
Paradigm Environmental: Ryan Edgley, Water Resources Engineer
ARLA: Deborah Bloom, Senior Policy Director
Ocean Health Index: Sophia Lecuona Manos
The DiPaola Foundation