Santa Cruz County
Coastal Climate Change Vulnerability Report
JUNE 2017
CENTRAL COAST WETLANDS GROUP
MOSS LANDING MARINE LABS | 8272 MOSS LANDING RD, MOSS LANDING, CA
Santa Cruz County Coastal Climate Change Vulnerability Report
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Santa Cruz County Coastal Climate Change Vulnerability Report
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Prepared by
Central Coast Wetlands Group at Moss Landing Marine Labs
Technical assistance provided by:
ESA
Revell Coastal
The Nature Conservancy Center for Ocean Solutions
Prepared for
The County of Santa Cruz
Funding Provided by:
The California Ocean Protection Council
Grant number C0300700
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Primary Authors:
Central Coast Wetlands group
Ross Clark Sarah Stoner-Duncan Jason Adelaars Sierra Tobin Kamille Hammerstrom
Acknowledgements:
California State Ocean Protection Council
Abe Doherty Paige Berube Nick Sadrpour
Santa Cruz County
David Carlson
City of Capitola
Rich Grunow
Coastal Conservation and Research
Jim Oakden
Science Team
David Revell, Revell Coastal Bob Battalio, ESA James Gregory, ESA James Jackson, ESA
GIS Layer support
AMBAG Santa Cruz County
Adapt Monterey Bay
Kelly Leo, TNC Sarah Newkirk, TNC Eric Hartge, Center for Ocean Solution
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Contents
Contents
Summary of Findings ........................................................................................................................ viii 1. Introduction ................................................................................................................................. 1
1.1. Background ...................................................................................................................................1 1.2. Coastal Commission Guidance......................................................................................................1 1.3. Geographic Scope of Study ...........................................................................................................2
2. Community Profile ....................................................................................................................... 4
2.1. Setting and Climate.......................................................................................................................4 2.2. Culture and Industry .....................................................................................................................4 2.3. Historical Context..........................................................................................................................5 2.4. Demographics ...............................................................................................................................5 2.5. Community Resources and Assets ................................................................................................5
3. Climate Science .......................................................................................................................... 14
3.1. Climate Change ...........................................................................................................................14 3.2. Sea Level Rise Projections...........................................................................................................16 3.3. State guidance.............................................................................................................................17 3.4. Coastal Hazards from Sea Level Rise...........................................................................................17 3.5. Current Planning Landscape .......................................................................................................18 3.6. Previous Studies and Reports in the Region ...............................................................................21
4. Vulnerability Assessment Methodology ..................................................................................... 24
4.1. Disclaimer: Hazard Mapping and Vulnerability Assessments.....................................................24 4.2. Coastal Hazard Processes............................................................................................................25 4.3. Scenario Selection and Hazards..................................................................................................27 4.4. Modifications to ESA Hazard Models..........................................................................................28 4.5. Data Compilation ........................................................................................................................29 4.6. GIS Mapped Assets Used for Analysis.........................................................................................30 4.7. GIS Vulnerability Analysis Methods ............................................................................................32
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4.8. Considerations Regarding New and Rebuilt Sea Walls ...............................................................33 4.9. Economic Analysis and Adaptation Alternatives ........................................................................34
5. Combined Impacts of Coastal Climate Change ............................................................................ 37
5.1 5.2
Existing Vulnerabilities................................................................................................................37 Future Hazards from Coastal Climate Change by Planning Horizon...........................................38
6. Vulnerabilities from Individual Coastal Hazards.......................................................................... 44
6.1 6.2 6.3 6.4 6.5
Section 1: Santa Cruz City Limit to Año Nuevo ...........................................................................44 Section 2: 7th Ave to Capitola.....................................................................................................46 Section 3: Seacliff to Manresa Beach..........................................................................................48 Section 4: Pajaro Valley from Sunset Beach to the County Line.................................................49 Future Risks to Specific Assets ....................................................................................................53
7. Economics of Future Climate Risks.............................................................................................. 59
7.1 Property valuation of vulnerable properties and infrastructure ................................................59
8. Adaptation Strategies Options.................................................................................................... 62
8.1 8.2 8.3 8.4
Adaptation Strategies by Coastal Hazard....................................................................................62 Strategies Listed Within Existing Plans .......................................................................................62 Adaptation Strategy Selection ....................................................................................................65 Potential Strategies for Climate Adaptation in Santa Cruz County by Time Horizon .................66
9. Conclusion.................................................................................................................................. 73
Possible Next Steps .................................................................................................................................73
Table 1. Major Floods in Santa Cruz County, 1861 to Present ...................................................................11 Table 2. Sea level rise scenarios selected for analysis ................................................................................28 Table 3. List of Assets Used in Analysis.......................................................................................................31 Table 4. Inventory of Existing Coastal Protection and Water Control Structures in Santa Cruz County....33 Table 5. Property valuation data sources for economic analysis ...............................................................35 Table 6. Specific assets vulnerable to coastal climate change hazards ......................................................58 Table 7. Total Value (2016 dollars) of Unincorporated Santa Cruz County Properties at Risk...................60 Table 8. Coastal infrastructure vulnerable to 2030 hazard projections. ....................................................66 Table 9. Coastal infrastructure vulnerable to 2060 hazard projections. ...................................................69 Table 10. Coastal infrastructure vulnerable to 2100 hazard projections. .................................................71
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List of Figures
Figure 1. Geographic Scope of Coastal Climate Change Vulnerability Analysis............................................3 Figure 2. The Greenhouse Effect.................................................................................................................14 Figure 3. Flowchart for addressing sea level rise in Local Coastal Programs and other plans ...................20 Figure 4. Sea Level Rise scenarios for each time horizon figure source: ESA PWA 2014 ..........................27 Figure 5. GIS Vulnerability Analysis Methodology for Point, Line, and Polygon features .........................32 Figure 6. Tide gates at Watsonville Slough flooded during a January 2017 king tide. ...............................41 Figure 7. Highway 1 at Scott Creek vulnerable to coastal erosion. ............................................................45 Figure 8. Resources along East Cliff vulnerable to Erosion.........................................................................47 Figure 9. Resources along Rio Del Mar vulnerable to Coastal Storm Flooding..........................................48 Figure 10. Tidal flooding hazard areas within the Pajaro Dunes ................................................................50 Figure 11. Low lying areas of the Pajaro Valley vulnerable to predicted 2030 storm flood hazards. ........51 Figure 12. Erosion hazard areas within the Pajaro Dunes ..........................................................................52 Figure 13. Numbers of residential buildings vulnerable to coastal climate change hazards. ....................53 Figure 14. Acres of farmland vulnerable to coastal climate change hazards. ............................................54 Figure 15. Feet of road and rail vulnerable to coastal climate change hazards .........................................55 Figure 16. Beaches along Santa Cruz County coast vulnerable to "Coastal Squeeze"...............................55 Figure 17. Number of coastal access points vulnerable to coastal climate change hazards......................56 Figure 18. Acres of Dune and Wetland habitat vulnerable to coastal climate change hazards .................57