Home Database Adaptation options Retreat from high-risk areas
Adaptation option

Retreat from high-risk areas

This measure refers to the strategic retreat or relocation of settlements, private households, infrastructures and productive activities from a risk to a non-risk location where they are resettled permanently. Retreat can be applied in pre- and post-disaster settings to reduce exposure to natural hazards when it is not possible to implement structural measures or their costs are too high. Retreat is often adopted in low-lying coastal zones, which are potentially sensitive to sea level rise and storm surges as well as more inland to address other types of hazards (e.g. river floods and erosion) that can become more severe in a climate change future looking perspective. Relocating potentially exposed assets away from hazard-prone areas ensures better safety of citizens and goods. In addition, it also can set up new space for nature to expand, favouring for example coastal ecosystem restoration.  

Managed retreat highly influences and is strongly impacted by private property rights. Therefore, the permanent movement of individuals is adopted as an extreme measure of risk management. Private landowners often receive a compensation to remove their houses from hazard-prone areas or, conversely, to remain in high-risk areas. The choice of who should receive compensation and who will pay the costs, as well as its amount and type, gives rise to social justice implications which should be carefully addressed when adopting this measure.  

In some cases, relocation from high-risk areas can be combined with the need of removing buildings constructed too close to beaches or rivers without proper authorisation.  

In a long-term perspective, spatial planning and building permissions can incorporate provisions for managed retreat. The Integrated Coastal Zone Management (ICZM) Protocol to the Barcelona Convention for the Protection of the Mediterranean Sea calls on Parties to establish a zone where construction is not allowed, the so-called “setback zone”. This zone should be set up preemptively, taking into account ‘climate change and natural risks’ (Art. 8). This provision is meant to avoid recurring relocation in the future.  

Examples of accomplished retreat and relocation measures are found throughout Europe. In southwestern France, a shoreline road in the municipalities of Sète and Marseillan (Languedoc-Roussillon region) was moved inland as it was threatened by erosion of the beach. This allowed the reconstruction of a larger beach and dune system, providing greater protection against erosion. Through road relocation and the restoration of dunes, infrastructures and people security were strengthened. This enabled the maintenance of the littoral’s core economic activities and the improvement of the landscape’s aesthetical value and natural habitats, with positive effects on tourism and recreational activities. 

In the context of river flooding, since the 1970s, the Austrian government (national, regional, and local authorities) has organised a managed retreat process for private households and businesses along the Danube River in moving more than 500 households. Compensation covering 80% of the value of the building as well as 80% of the demolition costs was offered to the affected householders. However, since compensation was only based on property value, most vulnerable groups living in less highly valued assets were penalised by this mechanism.   

The implementation of this measure must be coordinated at the proper spatial scale, fit to the specific local context and compliant with national and subnational regulations and plans. It specifically requires coordination with higher levels of governance and integration in land use planning. 

Additional Details
Reference information

Adaptation Details

IPCC categories

Institutional: Economic options, Institutional: Government policies and programmes

Stakeholder participation

Retreat from high-risk areas is often of high political and social controversy. The schemes frequently require more public acceptance due to a general lack of understanding real benefits of this option. Municipalities can be reluctant to modify their plans while setback zones are perceived as a loss of attractiveness of the territory and of economic development potential. Therefore coastal managers must involve all people affected by planning and decision-making process, communicating the true advantages and disadvantages of the approach. Effective stakeholder and local community engagement (local authorities, citizens, local businesses, tourism operators, and environmental NGOs is therefore essential for successfully implementing of relocation schemes and overcoming potential barriers. Ultimately, participation can help to:  

  • understand legitimate concerns and interests 
  • explain and convince the local community of a scheme’s merits;  
  • manage expectations;  
  • develop stakeholder ownership. 

Success and Limiting Factors

Success factors include: 

  • lower costs of retreat (including compensation), compared to other grey or green measures that protect assets where they are, especially in areas with low population densities. 
  • the possibility to combine retreat actions with restoration of natural features, such as vegetation buffers, wetlands, and dunes, that can provide landscape and biodiversity benefits as well as further protection against erosion, debris flows and floods. 

On the other hand, one of the biggest challenges of this adaptation option is that it requires people and businesses to relocate. People affected by relocations are confronted with profound changes in their lives. This requires overcoming the emotional attachment to the place, adapting to the new environment, coping with the financial burden, and re-building a new neighbourly social network. A lack of acceptance can also occur, especially when land with high perceived property value and development potential is affected. Whenever not well managed, retreat strategies can therefore be controversial and may result in strong opposition, in particular from homeowners and economic operators affected by land use change. Offering more appealing compensation schemes can overcome landowner opposition. However, the strong impact on private property rights and the choices underlining landowner’s compensation can raise issues of social justice. The needs and interests of the most vulnerable groups should be included in the policy design. Moreover, decisions on who should receive compensation, as well as its amount and type, should be carefully addressed in the planning phase.  

Public acceptance may also be reduced by a lack of community awareness or understanding of natural hazard phenomena and of how this measure mitigates coastal flooding and erosion. Retreat policies are likely to be more successful and receive stronger public support if they are designed from a long-term perspective. Incorporating alternative scenarios and long term projections of climate change into planning and management process can increase the overall understanding of climate risks and ultimately enhance public acceptance. Also, selecting the land where to retreat can be challenging and limit the implementation of this option. Since managed retreat can involve relocating numerous assets inland, natural, or agricultural land away from the coast is at risk of being artificialized. Moreover, land shortages or higher prices in the new area can impede the relocation. For instance, to overcome this problem, in the Eferdingen Becken area (Austria), the local authorities designated some limited special relocation areas and fixed land prices to avoid land price speculations.


Costs and Benefits

The main cost for this option is usually the cost of purchasing the land exposed to flooding or other hazards. The costs depend on the specific site and the settlements and infrastructure or land use concerned. As an example, agricultural land is usually less costly than land used for housing or industry, largely due to the presence of infrastructure. However, if land is used for housing or industry, additional compensation for relocation could be needed, increasing the overall costs of the intervention.  

Costs may increase further if it is necessary to dismantle human-made infrastructure in the new planned setback zone. This may include buildings and roads, underground pipes for gas delivery or wires for electricity, internet, or television. On the other hand, costs are likely to be lower if existing defences are left to breach naturally. This saves money which would have been spent creating artificial breaches. In Germany, the cost of relocation is seen as a major barrier to implementing this adaptation option since most of the North Sea defences are in excellent condition. The scale of monitoring operations post-realignment will also influence costs. 

The costs of retreat from high-risk areas need to be compared to those required for alternative actions, and to the value of the settlements of infrastructure that would be lost. For example, in Austria, relocation was carried out as an adaptation measure in Eferdinger Becken. A total cost of 250 million EUR was shared between the provincial (regional) and federal (national) government to compensate citizens 80% of the house’s value if they agreed to move. 

Retreating from high-risk areas brings several benefits beyond the increased safety for people and infrastructures. Managed retreat may favour ecological restoration of coastal areas, by providing new habitats for species as well as providing space for the creation, restoration, and conservation of dune ridges and salt marshes.  

The relocation of infrastructure may affect natural areas protected under the EU Natura 2000 network or other spatial conservation measures. This would require an appropriate assessment under the EU Habitats Directive. The construction of the new infrastructure may require assessment under the EU Environmental Impact Assessment (EIA) Directive. Retreat policies may need to take into account national property legislation and national and subnational land use plans. As noted above, the Mediterranean ICZM Protocol calls for a ‘setback’ strip along the coast where construction is prohibited. 

Implementation Time

The implementation time is highly site-specific. In general, implementing managed retreat constitutes a multidecadal sequence of actions, including community engagement, vulnerability assessment, land use planning, active retreat, compensation, and re-purposing. Long-term and strategic planning is required to implement managed retreat initiatives to ensure adequate stakeholder consultation and social acceptance. In Sète and Marseillan, South France, feasibility studies on the managed retreat of a coastal road and connected interventions of beach and dune restoration started in 2003 and were completed in 2005, including stakeholder consultations. Works (2007-2019) were then implemented in successive phases. Due to the complex nature of private property rights, retreat policies involving the relocation of houses and people usually involve a long process. Experiences from several cases in the Danube floodplains in Austria show that the process can take more than 10 years. 

Life Time

This measure overall represents a long-term approach to adaptation. Its long-term efficacy depends on the timeframe and accuracy of climate change projections embedded in the planning process. Setbacks need to be periodically reviewed to ensure that they continue to provide enough protection to population. 

Reference information

Published in Climate-ADAPT Jun 07 2016   -   Last Modified in Climate-ADAPT Aug 17 2023

Document Actions