Changing Maps, Changing Coastal Laws & Policies

Thursday, September 8, 2016

Imagine a map of sea-level rise in the year 2100. You know the ones—they show many of the world’s major coastal cities inundated by blue shading. With the sea predicted to rise one to two meters over that time, those maps are showing the consequences. Billions of people and trillions of dollars will be flooded out.

However, those maps only tell part of the story. Most of the world will not passively await the blue shading to come over them. Instead, local and national governments will adapt to sea-level rise. Through a suite of adaptation strategies, they will try to reduce impacts when possible and manage retreat when required.

ELI is currently partnering with local governments in San Diego to examine the law, policy, and economics of sea-level rise adaptation strategies. San Diego is not turning a blind eye to the sea-level rise projection maps. Rather, they are going into the uncertain future with eyes wide open, trying to find what works best for their citizens.

Sea-Level Rise Adaptation and the Potential for Legal Risk

From a legal perspective, sea-level rise adaptation poses a conundrum for local governments in southern California. On the one hand, they could decide not to act, exposing people and infrastructure to excess risk while potentially exposing themselves to litigation if their lack of action causes harm to individuals or public trust property. On the other hand, taking action may decrease risk to the community but increase litigation risk from aggrieved property owners or public interest groups depending on the nature of the action. Legal risk is thus unavoidable.

But different adaptation strategies (including the decision not to act) have different risk profiles. ELI is working to summarize legal risk for different adaptation strategies—incorporating it with economic cost-benefit analyses by a project partner—to facilitate informed decisionmaking.

Municipalities have three options to adapt to sea-level rise:

  • Protection: hard armoring (e.g., seawalls and revetments); soft armoring (e.g., beach nourishment and offshore protections); and certain types of green infrastructure.
  • Accommodation: zoning and land use tools to increase resilience (e.g., preventing armoring in certain areas).
  • Retreat: actively moving away from rising seas.

In practice, every California municipality’s Local Coastal Program (under California’s Coastal Act) uses some combination of these three strategies. The nature of that combination determines whether resilience goals are met, the costs and benefits of coastal management, and the legal risks involved.

In analyzing legal risk within the realm of adaptation strategies, the main legal principles at issue are the Public Trust Doctrine, the Takings Clause of the Fifth Amendment to the U.S. Constitution, the California Coastal Act (describing coastal management and permitting development), and the California Environmental Quality Act (essentially NEPA for state and local governments).

As an example of how these principles play out with sea-level rise, legal risk could arise under the Public Trust Doctrine when a private party or public-minded organization believes the government entity took its public trust responsibilities too far (or not far enough). Most often, when cases do arise, either plaintiffs’ private interests are the motivating force behind the litigation or public entities are seeking to protect public trust values for the broader benefit of the citizenry. For example, a private plaintiff might sue when denied a permit to build near the mean high tideline. A public-minded organization may sue to prevent beach nourishment on the theory that it is not a valid trust purpose.

Legal risk under the Takings Clause primarily arises from aggrieved private-property holders. Examples include a beach nourishment project that leads to pooling on private property (subject to an inverse condemnation claim), denial of a building permit on or near the high tideline (subject to analysis as a partial diminution in property value), or permit conditions that forbid or restrict seawalls (subject to regulatory takings analysis), among other situations.

Our project applies these and other legal principles to numerous adaptation strategies and fact-specific scenarios to find out where legal risks arise most often and how they can be mitigated for more efficient adaptation.


Sea-level rise has no precedent. And it’s happening fast. Every day, governments around the world are making decisions that will impact generations to come. Sea-level rise certainty mixes with legal and economic uncertainty to create a potent brew that could be bitter to swallow for governments that do not prepare now. San Diego is proactively looking at ways to help their citizens by getting ahead of the coming blue wave that will envelop most coastal maps in the coming decades and centuries.

Maps are changing. Coastal law, policy, and decisionmaking need to change with it.