Sea Level Rise Vulnerability Study for the City of Los Angeles

Created: 2/20/2014 - Updated: 3/02/2020

Summary

Over the next century, sea level rise in the Los Angeles region is expected to match global projections with an increase of 0.1 - 0.6 m (5 - 24 inches) from 2000 to 2050 and 0.4 - 1.7 m (17 - 66 inches) from 2000 to 2100. Tides, wave-driven runup, and storm surge sometimes cause coastal flooding in Southern California, especially when big wave storms occur at or near peak high tides. Sea level rise will potentially exacerbate the impacts from these events. The City of Los Angeles owns and maintains coastal infrastructure that includes two power plants, two wastewater treatment plants, and the Port of Los Angeles, one of the busiest in the world. All of these are situated about ten feet above sea level. In addition, a major component of Los Angeles’s economy is dependent upon beach tourism. In 2012, the Los Angeles region attracted over 41 million tourists, who accounted for more than US$16.5 billion in expenditures. The University of Southern California Sea Grant Program engaged city managers and a team of science and outreach experts to develop a science-based and stakeholder-supported adaptation planning process in order to assess the City’s vulnerabilities and begin to prepare for accelerated sea level rise and associated storm impacts. The expert team conducted an assessment of the potential physical, social, and economic impacts of sea level rise on the City’s resources and population, as well as impacts to coastal and shoreline assets.

Background

In 2011, the City of Los Angeles engaged the University of Southern California (USC) Sea Grant Program, along with the Los Angeles Regional Collaborative on Climate Action and Sustainability (LARC) and ICLEI – Local Governments for Sustainability, U.S.A. (ICLEI), to begin research into the impacts of sea level rise on the City’s coastal assets, resources and communities.

In December 2011, USC Sea Grant and the City launched this project, locally called AdaptLA: a science-based and stakeholder-supported sea level rise adaptation planning effort. The methodology 1) supports the City in identifying the vulnerabilities of its coastal assets, resources and communities to sea level rise; 2) provides information for developing meaningful and effective adaptation strategies; and 3) builds on the City’s ongoing environmental and climate policies. The project involved a high degree of stakeholder engagement. Three teams were developed to support the project, a critical key to its long-term success. These include an Adaptation Planning Team; the City Adaptation Leadership Team (CAL); and a Regional Stakeholder Working Group (RSWG).   

 

Implementation

Staff used an adaptive adaptation planning approach as represented in Figure 2. This process includes four major steps:

  1. Identification of current observed vulnerabilities to coastal resources and communities in the region.
  2. Assessment of the vulnerability of coastal resources and assets to sea level rise with respect to social, economic, and ecological factors.
  3. Identification of adaptation measures to the expected impacts of sea level rise.
  4. Development of a sea level rise adaptation plan approved by the Mayor and City Council.

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This project addressed Steps 1-2 in the development and publication of the report, Sea Level Rise Vulnerability Study for the City of Los Angeles, which focuses on the potential impacts of sea level rise and associated coastal flooding for the coastal communities of the City of Los Angeles. We highlight the findings of a coastal issues report; three vulnerability assessments that provide a preliminary examination of the physical, social, and economic impacts of sea level rise on the City of Los Angeles; and a discussion of ecological vulnerability at Ballona Wetlands. We conclude the report with a set of guidelines for identifying and evaluating possible adaptation strategies and measures to address these potential vulnerabilities. This report is meant to provide a first glimpse into the vulnerabilities the City of Los Angeles may face under rising sea levels and to start building the capacity within the City to begin an adaptive approach to planning for sea level rise and other climate change impacts.

Outcomes and Conclusions

Major findings of this effort include:

  • The City’s wastewater management, stormwater management, potable water systems and roads are highly vulnerable to sea level rise.
  • The Port of Los Angeles and the City’s energy infrastructure have relatively low vulnerability to sea level rise.
  • City parks and open areas are moderately vulnerable to flooding, because they can be restored fairly quickly.
  • Museums and other coastal structures have higher vulnerability because of structural damage that may result from flooding.
  • Roads are vulnerable to flooding and erosion, which may impede emergency services.
  • Some coastal building stock is highly vulnerable – particularly in Venice, where historic buildings and much of the community are at or near sea level.
  • Some coastal communities, especially Venice and low-lying Wilmington and San Pedro, are home to highly vulnerable populations who may be unable to adapt to impacts of sea level rise because of social or economic challenges, including lower per capita income, lower education levels, linguistic isolation, older housing stock, and a high percentage of renters.
  • Direct financial losses from building stock (with a 10-year storm event) are expected to exceed US$410 million with a 0.5 m rise in sea level, or as much as US$714 million with a 1.4 m rise in sea level.

Next Steps:

There has been a strong move among Los Angeles regional partners to expand the work of AdaptLA to examine impacts and vulnerabilities across the region. USC Sea Grant and coalition of partners assisted the region led in applying for state funding to support regional sea level rise planning and modeling. The state awarded the City of Santa Monica on behalf on the region funding to initiate this effort. USC Sea Grant will also be partnering with the State of California to provide training and outreach across Southern California to educate local users on the science driving dynamic models, provide training, and ensure new models meet the needs of local planners and managers.

Status

Submitted by CAKE user and edited by CAKE Content Editor

Image: Kevitivity via Wikimedia Commons

Citation

Newton Mann, A. (2014). Sea Level Rise Vulnerability Study for the City of Los Angeles. Ed. Rachel M. Gregg. [Case study on a project by USC Sea Grant]. Retrieved from CAKE: www.cakex.org/case-studies/sea-level-rise-vulnerability-study-city-los-angeles (Last updated February 2014).

Project Contact(s)

Position: Regional Research & Planning Specialist

The University of Southern California, one of the largest private universities in the United States, has participated in the National Sea Grant College Program for over 30 years and has more than a 100-year history of marine science research in Southern California. USC's facilities, research, and curricula make it the principal university in the Los Angeles region for ocean studies, and it has demonstrated excellence in marine research and education from the beginning of the 20th Century.

Keywords

Target Climate Changes and Impacts
Air temperature
Culture / communities
Erosion
Infrastructure damage
Precipitation
Public health risks
Public safety threats
Sea level rise
Storms or extreme weather events
Climate Type
Temperate
Timeframe
1-3 years
Type of Adaptation Action/Strategy
Capacity Building
Conduct / Gather additional research, data, and products
Conduct vulnerability assessments and studies
Sociopolitical Setting
Urban
Effort Stage
Completed

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