In many places across the globe, sandy shorelines are under threat from rising sea levels. If coastal retreat of beachfront infrastructure and property does not keep pace with sea level rise, some of the world’s most iconic beaches could be lost. Even in areas where beaches are protected by law as a public amenity, beach loss is already underway.

To explore underlying factors impacting coastal retreat and beach preservation, researchers in Hawai’i interviewed a range of government, private sector and community group stakeholders in relation to three threatened beaches on the island of O’ahu, Hawai’i.

The interviews highlighted the local complexities, but also the broad commonalities of legal and economic constraints, that coastal communities face in relation to coastal retreat. The interviews also emphasised the need for a broader range of perspectives, far beyond beachfront property owners, in community consultation and planning for beach preservation and coastal retreat.

Despite the strong consensus among study participants that O’ahu’s beaches should be preserved, and the broad recognition of the social and ecological benefits that the beaches provide, managed retreat of coastal property and infrastructure was not seen as a viable policy position in Hawai’i in the near term.

On the world-renowned big wave surfing location of Sunset Beach, where powerful waves generate extreme seasonal erosion, some retreat was seen as inevitable to preserve the beach. But around the coast in Ka’a’awa, where the community is located on a thin strip of land between mountains and the ocean, there is little to no land to retreat to. A highway adjacent the Ka’a’awa coastline – the sole access point for emergency vehicles, and beneath which lies the water main for the eastern end of the island – was seen as critical infrastructure that many interviewees felt had to be protected in place.

More broadly, however, the key barriers to managed coastal retreat and beach preservation were legal and economic. Just the enforcement of existing shoreline regulations – such as laws on private property owners installing sea defences – has become increasingly combative, with beachfront homeowners increasingly fighting local authorities through the courts. Managed retreat was expected to be even more strongly legally contested.

Interviewees also raised concerns about managed coastal retreat based on governments acquiring private beachfront land. The concerns focused on whether this was a fair and sustainable use of public finances, but also that such policies would 'de-risk' investment in beachfront property, further inflating the market for this real estate.

When planning for coastal retreat, a key consideration was expanding community engagement to include a broader range of participants than typically takes place currently, to gain a diverse range of perspectives. Beachfront property owners tend to be vocal and highly engaged participants in community planning, but they represent just one subset of a wider community with connection to the beach and affected by coastal retreat decision making.

In Hawai’i, the traditional custodians of coastal areas and beaches, with longstanding connection to place, were identified as a key group to bring into consultation.

Stakeholders to be consulted should also extend far beyond the local area. On some beaches, interviewees identified tourists as stakeholders, noting that the surfers who gather on Hawai’i from around the world could help to bring a global perspective, and contribute to building a broad consensus on coastal zone management and adaptation.

Also highlighted was the desirability to initiate community discussions early, before the situation becomes an emergency.

This case study was prepared by NCCARF. Please cite as: NCCARF, 2024: Stakeholder perceptions of priorities and challenges of managed retreat in Hawaii. Case study for CoastAdapt, National Climate Change Adaptation Research Facility, Griffith University, Gold Coast.