Coastal areas are facing increasing and evolving risks from inundation and erosion driven by sea‑level rise, changing storm patterns, and potential shifts in wind and wave conditions. These risks tend to intensify over time and often interact with existing coastal pressures.

In response, local councils, infrastructure owners and coastal businesses are increasingly undertaking adaptation planning to manage both current exposure and future risk.

Effective coastal adaptation planning recognises that there is rarely a single or permanent solution. Instead, a range of options should be considered and tested against factors such as risk level, timing and decision triggers, funding availability, organisational capacity, and community environmental, social, cultural and economic values. This supports informed, flexible decision‑making under uncertainty.

Coastal adaptation responses are commonly grouped into five broad categories: avoidance, managed retreat, accommodation, hold the line, and loss acceptance. Together, these categories provide a practical framework for managing risk, from preventing new exposure through to accepting residual impacts where intervention is no longer viable or appropriate.

Below we define each adaptation category and link to more information on potential options that can be selected, combined and sequenced as part of long-term adaptive, coastal management.

While a wide range of adaptation options exists for managing coastal climate risks, all options have limits, beyond which they become technically, economically or socially ineffective or unacceptable.

As sea‑level rise accelerates and coastal hazards become more frequent and severe, residual risks - the risk that remains even after adaptation - are expected to increase even where adaptation actions are implemented.

Long term planning therefore requires identifying key thresholds, such as the frequency of inundation, rate of erosion, or escalating maintenance costs at which particular options cease to be viable.

Failure to account for these limits can lead to maladaptation or delayed decision‑making, increasing long‑term exposure to loss and damage.

The five adaptation categories can be broadly understood to overlap along a spectrum from incremental adaptation (which seeks to maintain existing land uses and assets through accommodation or protection) to transformational adaptation (which involves fundamental changes in where and how people live and invest in coastal areas).

Managed retreat and, in some cases, loss acceptance are increasingly recognised as transformational responses, particularly in locations where in‑situ adaptation options are no longer sufficient to manage rising risks.

Most coastal communities will require a combination of adaptation strategies over time; while many will need to transition between adaptation strategies over time through an adaptation pathways approach.

It is no longer realistic to rely on a single, static strategy for long term coastal risk management.

An 'avoidance' strategy focusses on reducing or eliminating exposure to future coastal climate hazards by preventing new development or intensification of assets (e.g. infrastructure, housing developments) in areas that are likely to become increasingly affected by inundation, erosion or storm impacts under climate change.

An avoidance strategy is typically implemented through planning and regulatory mechanisms such as coastal hazard mapping, development controls, zoning restrictions, setbacks and disclosure requirements. These measures aim to ensure that today's decisions about future land use and investments do not create new long‑term liabilities in areas affected by future climate change impacts, particularly sea‑level rise and coastal flooding.

Avoidance is most effective when applied early, before high value assets are established, and when combined with adaptation pathways that allow planning and regulatory controls to tighten over time as risks increase.

Managed retreat (also referred to as planned retreat or planned relocation) involves the purposeful, coordinated and often phased movement of people, buildings and infrastructure away from areas of increasing coastal risk.

Rather than responding after disasters, managed retreat seeks to reduce long‑term exposure and losses by proactively relocating assets out of harm’s way.

Successful managed retreat depends on more than planning and engineering measures (such as buy‑back programs and infrastructure relocation). It requires strong governance, community engagement, equity considerations and social support mechanisms to address impacts on livelihoods, place attachment and wellbeing.

Accommodation allows for the continued use (rather than avoidance or retreat) of coastal areas while modifying assets, behaviours or management practices to reduce vulnerability to climate hazards, rather than avoiding or retreating from those areas.

Accommodation measures typically include raising floor levels, flood‑proofing buildings, modifying building codes, changing land uses to less sensitive activities, improving emergency management, and introducing early‑warning and evacuation systems.

Accommodation can be an effective interim or medium‑term strategy, particularly where communities wish to maintain access and use of coastal areas and values. However, it does not eliminate risk and may reach limits as sea‑level rise and erosion intensify, making it a stepping stone in an adaptation pathway.

A protect or hold the line strategy involves actively keeping the shoreline in its current position through ongoing intervention. This typically involves constructing and maintaining coastal protection works designed to reduce erosion and manage inundation risk.

In practice, hold‑the‑line approaches usually rely on hard engineering structures such as seawalls, revetments, groynes and levees, and are often supported by soft or hybrid measures including beach nourishment, dune management and the incorporation of nature‑based features.

While hold‑the‑line approaches can protect high‑value assets in the short to medium term, they involve significant long‑term considerations. These include rising maintenance costs, impacts on coastal ecosystems and sediment processes, risk of erosion in adjacent areas, and the potential for maladaptation if future conditions exceed design assumptions.

Loss acceptance involves a deliberate, informed decision to accept ongoing or future losses from coastal climate risks, either temporarily or permanently, without implementing additional adaptation interventions at the present time.

Loss acceptance should be an active, documented choice, rather than default outcome. The use of this strategy should be based on an understanding of risk, costs, benefits, social values and the timing of future action triggers.

Loss acceptance may be appropriate where risks are currently low, adaptation options are not yet cost‑effective, or where future transformation (such as retreat) is anticipated and planning pathways are in place to guide later action.