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UC Santa Cruz UC Santa Cruz Electronic Theses and Dissertations Title Flood risk and management of California's Sacramento-San Joaquin Delta levee system Permalink https://escholarship.org/uc/item/1k82h517 Author Rittelmeyer, Pamela Publication Date 2020 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA SANTA CRUZ FLOOD RISK AND MANAGEMENT OF CALIFORNIA'S SACRAMENTO-SAN JOAQUIN DELTA LEVEE SYSTEM A dissertation submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in ENVIRONMENTAL STUDIES by Pamela F. Rittelmeyer September 2020 The DissertAtion of PAmelA F. Rittelmeyer is Approved: Professor Emeritus Andrew SzAsz, Chair Professor Michael Loik Professor Ellen Hines Quentin WilliAms Interim Vice Provost and DeAn of Graduate Studies Copyright © by Pamela F. Rittelmeyer 2020 TABLE OF CONTENTS List of Figure and Tables vii Figures vii Tables ix Abstract x Dedication xii Acknowledgements xiii Chapter 1: Introduction 1 Chapter 2: Socio-Cultural Perceptions of Flood Risk and 4 Management of a Levee System: Applying the Q Methodology in the California Delta 1. Introduction 4 1.1 Sacramento-San Joaquin Delta 5 1.2 The Need for New Ways to Understand Stakeholders’ 7 Perceptions 2. Methods 7 2.1 Q Methodology 7 2.2 The Q Concourse and Q Set 8 2.3 Q Sorters 8 2.4 Q Sorting Procedure 9 2.5 Analysis 9 3. Findings 9 3.1 Factor 1a: Crisis is certain 9 iii 3.2 Factor 1b: There is no crisis 11 3.3 Factor 2: Locals are resilient 11 3.4 Factor 3: Nature is resilient 12 3.5 Factor 4: Human ingenuity will prevail 12 3.6 Consensus statement 13 4. Discussion 13 4.1 Uncertainty of scale 13 4.2 Place and proximity 13 4.3 Trust 13 4.4 Agency, vulnerability, and adaptive capacity 14 5. Conclusion 14 Acknowledgements 14 References 15 Chapter 3: Media Coverage of Flood Events in the Sacramento- 17 San Joaquin Delta, 1972-2019 1. Introduction 17 1.1. Issue framing of floods and climate change in the media 19 1.2 Study Area 20 2. Data and Methods 22 2.1 Data Collection 22 2.2 Data Analysis 25 3. Findings 26 iv 3.1 The voices 30 3.2 The narratives 32 3.2.1 Concern 33 3.2.2 Blame 35 3.2.3 Solutions in the narratives 41 4. Discussion and Conclusion 52 Chapter 4: Timing of Atmospheric Rivers and Flooding in the 55 Sacramento-San Joaquin Delta from 1980-2019 Abstract 55 1. Introduction 56 1.1 Study Area 58 1.1.1 Levee development 58 1.1.2 Levee improvements 62 1.2 Atmospheric Rivers 65 2. Methods and Data 68 2.1 Flood data 68 2.2 Atmospheric river data 69 3. Results 71 3.1 Floods and levee failures 71 3.2 Atmospheric river frequency and intensity 72 3.3 Timing of atmospheric rivers and floods 75 4. Discussion 77 v Summary of findings 80 Chapter 5: Conclusion 81 Appendices 83 Appendix A. Scree plot for Q study 83 Appendix B. Newspaper interviewees 84 Appendix C. R code for atmospheric rivers and floods 86 Bibliography 94 vi LIST OF FIGURES AND TABLES Figures Chapter 2 Fig. 1. Boating by a marina in the Delta. 5 Fig. 2. An agricultural island in the Delta. 6 Fig. 3. Map of the study area 6 Chapter 3 Fig. 1. The locations of the 12 newspapers in this study 25 Fig. 2. Number of types of interviewees quoted each year 31 Fig. 3. Total percent of interviewee type in each newspaper 32 Fig. 4. Number of articles reporting of damages by year 34 Fig. 5. Number of articles in each newspaper reporting on 35 damages from floods Fig. 6. Number of times possible cause of flood mentioned in 37 articles by year Fig. 7. Percentage of causes of flood in each newspaper 41 Chapter 4 Fig. 1. Map of project and non-project levees within the Delta 61 Fig. 2. Map of the Delta, the watersheds that feed into the Delta, 68 and the areas that use Delta water Fig. 3. Frequency of floods based on type of levee and degree of 71 the failure Fig. 4. Total number of floods by month and year from 1980-2019 72 vii Fig. 5. Frequency of all ARs in the study region from WY 1980- 74 2019, and their corresponding category of intensity, mean, and regression lines over time Fig. 6. Level of risk of all ARs in the Delta, and the proportion 76 coming from each of the watersheds Fig. 7. Timing of floods, the relative AR strength, location of AR 77 landfall, and the outcome of the flood viii Tables Chapter 2 Table 1. Major federal, state, and regional agencies with Delta 5 interests. Table 2. Statements and grid positions of idealized factor arrays. 10 Table 3. Correlations between factor scores 11 Table 4. Factor statistics and participants’ affiliations. 11 Table 5. Risk perception characteristics of the five perspectives. 14 Chapter 3 Table 1. Distribution of articles by year and newspaper 26 Table 2. Characteristics of flood events in this study 28 Chapter 4 Table 1. Floods in the Delta by island or tract between 1980 and 64 2019 Table 2. Scales of AR intensity and thresholds of risk based on 70 analyses of ARs that have made landfall on the US West Coast Table 3. Regression coefficients and number of observations of 74 each of the five scales of AR strength ix ABSTRACT FLOOD RISK AND MANAGEMENT OF CALIFORNIA'S SACRAMENTO-SAN JOAQUIN DELTA LEVEE SYSTEM Pamela Rittelmeyer The Sacramento-San Joaquin Delta is a highly developed floodplain and the hub of the state’s water supply system. It is an agricultural, recreational, historical, and cultural center where 1800km of levees protect the current land uses and prevent salinity intrusion into the freshwater supply. For decades the region has been ripe with political controversies stemming from conflicting interests over its natural resources. The threat of climate change has added a layer of urgency to understanding the mobilization of narratives at different scales. This dissertation is comprised of three distinct parts. I used the Q methodology to explore the discourses of the broad range of stakeholders about flood risk and flood management in the Delta. The results of the Q-study reveal five distinct views regarding the risk of submersion of one or more islands due to either overtopping during high waters or structural levee failures. Proximity, sense of vulnerability, values, trust, and views of climate change are the underlying factors in these perspectives. Then, using a collection of 345 newspaper articles from twelve different publications written between 1972 and 2017, I examined the trends and shifts in the narratives about floods in the Delta. Results show changes in framing over time and differences between local, regional, and national media. Lastly, I analyzed the characteristics of atmospheric rivers that x have preceded floods in the Delta using MERRA-2 0.5 × 0.625 6-hourly global atmospheric river (AR) reanalysis V2.0 and details about 57 documented floods from 1980 to 2019. Results show that most of the ARs that have made landfall in the watersheds that feed the Delta are not severe. Most of the floods, however, have been preceded by strong ARs. The most recent years (1999 to 2019) have had a small number of floods, and even fewer levee failures. However, the most recent ARs that impacted the Delta made landfall in the San Joaquin watershed, not the Sacramento watershed, which was the predominant origin of the more destructive floods in the earlier decades of this study. xi This dissertation is dedicated to my amazing husband and daughter, Nobuo and Naomi, for their love, patience, and never-ending encouragement. xii ACKNOWLEDGEMENTS This work was made possible by financial support from a Delta Science Fellowship awarded by Delta Stewardship Council Delta Science Program (R/SF- 86 grant number 1167), California State University’s Chancellor’s Doctoral Incentive Program, CONCUR, Inc.’s Environmental Studies Scholarship, a Marilyn C. and Raymond E. Davis Memorial Scholarship, a University of California Regents Fellowship, and the Environmental Studies Department at the University of California, Santa Cruz. I am grateful for the guidance from my dissertation committee, Dr. Andrew Szasz, Dr. Michael Loik, and Dr. Ellen Hines, and also my qualifying committee members, Dr. Zdravka Tzankova and Dr. Gary Griggs. I received assistance from many people in the California Sacramento-San Joaquin Delta, including Dave Mraz, Gilbert Cosio, Emily Pappalardo, Dr. Jeffrey Mount, and too many others to list them all here! I thank Dr. Brent Haddad and Dr. Kai Zhu for their input and technical assistance. Last, but not least, I greatly appreciate the brainstorming and research that my intern Ash Nee-Amshoff contributed during the early phase of my research design for the Q-methodology and media analysis. The text of this dissertation includes a reprint of the following previously published material: Rittelmeyer (2020). Socio-cultural perceptions of flood risk and management of a levee system: Applying the Q methodology in the California Delta. Geoforum, 111, 11–23. https://doi.org/10.1016/j.geoforum.2020.02.022. xiii INTRODUCTION In ’97 we passed the flood of record, which I believe was 93,000 cfs at Michigan Bar. Those flood flows were attenuated because of all those levee breaks high in the Consumes system – I believe there were 26 breaks – that allowed that water to spread out over the floodplain. We did not get the flood that DWR projected we would get.