California Sea-Level Rise Guidance - 2018 Update
The Ocean Protection Council’s 2018 update of the California Sea-Level Rise Guidance is designed in support of state agencies and local governments preparation for and adaption to sea-level rise (SLR). The report includes a step-by-step approach to SLR risk analysis, and incorporating these projections into planning, permitting, and investment decisions. Recommended adaptation strategies are given for priorities such as bolstering the resilience vulnerable communities and coastal habitats, and incorporating climate change impacts into project design and coastal planning. The 2018 update includes new sea-level rise projections, and an extreme sea-level rise scenario caused by rapid ice loss from the West Antarctic ice sheet.
The report summarizes the best available sea-level rise science and modeling from the 2017 report, “Rising Seas in California: An Update on Sea-Level Rise Science,” with an increased understanding of sea-level rise projections and polar ice sheet loss. To ensure decision making in light of the best available science, this new data as well as new policy and legislative directives warranted an update to California’s sea-level rise guidance.
This Guidance provides a step-wise approach to assess risk by evaluating a range of SLR projections and the associated impacts - and evaluate various planning decisions in relation to these risks. The decision framework includes the following steps, which are detailed in the report:
- Identify the nearest tide gauge.
- Evaluate project lifespan.
- For the nearest tide gauge and project lifespan, identify range of sea-level rise projections.
- Evaluate potential impacts and adaptive capacity across a range of sea-level rise projections and emissions scenarios.
- Select sea-level rise projections based on risk tolerance and, if necessary, develop adaptation pathways that increase resiliency to sea-level rise and include contingency plans if projections are exceeded.
The report includes substantial coastal resilience planning support in the Recommendations for Sea-Level Rise Planning and Adaptation section. Detailed actionable strategies are illustrated for each of the following 8 recommendations:
1. Adaptation planning and strategies should prioritize social equity, environmental justice and the needs of vulnerable communities.
Strategies are outlined for SLR planning that addresses social equity, environmental justice and protection of vulnerable communities - including early public engagement of those who will affected, and the discernment of impacts of those dependent on critical assets threatened by SLR. Other strategies to consider are described, for example, to:
2. Adaptation strategies should prioritize protection of coastal habitats and public access.
3. Adaptation strategies should consider the unique characteristics, constraints and values of existing water-dependent infrastructure, ports and Public Trust uses.
4. Consider episodic increases in sea-level rise caused by storms and other extreme events.
5. Coordinate and collaborate with local, state and federal agencies when selecting sea-level rise projections; where feasible, use consistent sea level rise projections across multi-agency planning and regulatory decisions.
6. Consider local conditions to inform decision making.
7. Include adaptive capacity in design and planning.
8. Assessment of risk and adaptation planning should be conducted at community and regional levels, when possible.
OPC developed the 2018 guidance with a policy advisory committee including representatives of the California Natural Resources Agency, the Governor’s Office of Planning and Research, and the California Energy Commission. OPC also collaborated with state coastal management agencies and other members of the state’s Coastal and Ocean Working Group of the California’s Climate Action Team. In addition, OPC solicited input from coastal stakeholders including local governments, regional and federal agencies, environmental groups, Tribes and others.
Publication Date: March 14, 2018
- Agency guidance/policy