In the past century, global mean sea level has increased by 7 to 8 inches with human influence the dominant cause of observed atmospheric and oceanic warming. Given current trends in greenhouse gas emissions and increasing global temperatures, sea level rise is expected to accelerate in the coming decades, with scientists projecting as much as a 66-inch increase in sea level along segments of California's coast by the year 2100. While over the next few decades, the most damaging events are likely to be dominated by large El Niño - driven storm events in combination with high tides and large waves, impacts will generally become more frequent and more severe in the latter half of this century.

The impacts of sea level rise in California will affect almost every facet of our natural and built environments. Natural flooding, erosion, and storm event patterns are likely to be exacerbated by sea level rise, leading to significant social, environmental, and economic impacts. Through its Sea Level Rise Policy Guidance and ancillary efforts, the Coastal Commission advances, supports, and helps to fund California's preparation for these critical challenges to ensure a resilient coast for present and future generations.

Informational Guidance on Sea Level Rise Planning

Events and Highlights

  • Sea Level Rise Guidance for Critical Infrastructure Adopted by Commission: At its November hearing, the California Coastal Commission adopted a guidance document for critical infrastructure adaptation planning, titled: Critical Infrastructure at Risk: Sea Level Rise Planning Guidance for California’s Coastal Zone. With a focus on water and transportation infrastructure, the goal of the Guidance is to promote resilient coastal infrastructure and protection of coastal resources by providing local governments, asset managers, and other stakeholders with policy and planning information to help inform sea level rise adaptation decisions that are consistent with the Coastal Act.

  • Interagency Sea Level Rise Awareness Campaign: On September 28, the Ocean Protection Council, in partnership with the Coastal Commission and other state agencies, launched a Sea Level Rise Awareness Campaign called “The Ocean Is Moving In.” The statewide campaign raises awareness about the urgent threat that sea level rise poses to coastal and inland communities. It features light-hearted videos (which have been posted on OPC’s YouTube page) and posters of various sea creatures taking up residence in people's homes, with the goal of inspiring people to visit the state’s new sea level rise website,, where they can learn more about sea level rise and how to take action. A media kit has been distributed among state agencies so that they can share the videos, website, and other social media content.

  • SLR and Rising Groundwater Briefing: On September 8, 2021 the Coastal Commission heard an informational briefing by a team of scientists from USGS and the University of Arkansas on a new statewide model that shows how sea level rise could cause coastal groundwater tables to rise and the implications that could have for adaptation planning. Click here to view a video of the briefing and here to view the slide presentation. The model can be accessed at and a video demonstration of how to use the website can be viewed here.

More Information on Sea Level Rise

Legal Authority & Legislation

The Coastal Act mandates the California Coastal Commission to "protect, conserve, restore, and enhance" the state's coastal resources. Policies on hazard avoidance and coastal resource protection provide the basis for the Commission to consider the impacts of sea level rise. The Commission has long considered sea level rise, erosion rates, and other effects of a dynamic climate in its analysis of permits and LCPs, staff recommendations, and Commission decisions. When Section 30006.5 was added to the Coastal Act in 1992, it directed the Commission to both develop its own expertise and interact with the scientific community on various technical issues, including coastal erosion and sea level rise, specifically.

Relevant Coastal Act Policies


Federal & State Context