Perceptions of Risk and Management of the Delta Levee System

Levee on Sherman Island
R/SF-86
Start/End: April, 2017 to March, 2019

Delta Science Fellowship 2017-19

Fellow: Pamela Rittelmeyer, Doctoral Student, University of California, Santa Cruz
Research mentor: Andrew Szasz, Environmental Studies, University of California, Santa Cruz
Community mentor: Dave Mraz, California Department of Water Resources

Background

As a central hub of California’s water supply, transportation, and agricultural systems, the Sacramento-San Joaquin Delta is precariously positioned for change as a result of climate change, sea level rise, and its seismic activity. While there is an extensive body of scholarship about the Delta’s levees, the question remains of how the various perceptions of flood risk in the Delta align with the suite of potential adaptation measures. Research on how stakeholders perceive management planning and historical issues in the Delta levee system is critical to analyzing obstacles in the region.

Project

This project aimed to identify key drivers in the resistance for reconciling expert opinion, stakeholder interests, and landowner priorities. In doing so, the proposed research will specifically assess the economic and environmental sustainability and viability of consolidated islands (polders), expanded waterways, and setback levees.

By identifying key drivers in resistance for reconciling expert opinion, stakeholder interests, and landowner priorities, this research will increase the understanding of how social values motivate the measures supported for adaptation to climate change. In particular, Rittelmeyer explored the viability of alternatives to the current levee system, such as consolidated islands (polders), expanded waterways, and setback levees.

Progress/Results

This project used social science methodology explore the structure and content of a diverse group of stakeholders’ subjective beliefs of flood risk and management.

The data collection included interviews with experts on delta flood management, focusing on the history of the delta, attempts at solutions, current threats and risks, and possible management solutions. Data also included participant observation at public meetings, and analysis of hundreds of public comments and media coverage. Ongoing work for this study includes an analysis of framing of past flood events in the news media and also a geospatial analysis of the relationship between atmospheric and hydrological conditions during past extreme flood events.

The results of this study reveal five distinct views regarding the risk of flooding due to levee failures. The findings of this study also elucidate nuanced narratives on the viability of anticipatory climate change adaptation in the delta. Proximity, sense of vulnerability, values, trust, and views of climate change are the underlying factors in these perspectives. The five perspectives shared the view that residents will need to adapt in the future; however, they differed in their view of what constitutes adaptation.

Management Applications

Management in the delta continues to face a major challenge to resolve decades of distrust among stakeholder groups. There are a number of interagency and science advisory boards working on this problem, however, current efforts do not take social values into the analysis..

This research is being used by the California Department of Water Resources as they develop more comprehensive plans for the delta levee system. The insights gained from this research will influence the policy that will move the delta to be better prepared for natural hazards.

Publications and Presentations

Rittelmeyer, P (2018). Perceptions of Flood Risk and Management of the Delta Levee System. Bay Delta Science Conference. Sacramento, CA. September 2018.

Rittelmeyer, P (2018). Perceptions of Flood Risk and Management of the California Delta Levee System. International Society for the Scientific Study of Subjectivity. Charlotte, NC. October 2018.

Rittelmeyer, P (2019). Meanings behind perceptions: Flood Risk and Management of the California Delta Levee System. American Association of Geographers. Washington, DC. April 2019