What is managed retreat?
Managed retreat is “the purposeful, coordinated movement of people and assets out of harm’s way” [2]. An example of managed retreat would be relocating people living in a flood-prone region to a safer area; as was the case in Valmeyer (Illinois) in the 1990s, after the great Midwestern flood of 1993 [2]. Below is a simplified representation of managed retreat [3].
Managed retreat can be complicated and involve a number of different aspects, such as: coastal planning; relocation, buy-back and buy-out programs; regulating the types of development allowed; designating no-build areas; habitat restoration; replacement of built environment with green space, etc. [4]. Ajibade et al. (2022) identified 138 case studies from literature about managed retreat projects (either finalized or ongoing) around the world; the geographical distribution of those is shown in figure 2, with North America having the most projects. In terms of Global North/South, it is fairly equal with 68 in the Global North and 70 in the Global South [5].
How does it work in the US?
The most common tool used by US authorities is “voluntary property acquisition”. Authorities buy properties that are at risk of flooding and the owners relocate. This aims to reduce costs of future emergency responses and disaster recovery while also reducing the burden on the National Flood Insurance Program (NFIP) [6]. The latter is a public-private partnership managed by the Federal Emergency Management Agency (FEMA), and provides flood insurance [7]. Figure 3 shows where in the US such programs exist.
Funding is most often, but not always, provided by the federal government, while the administering is done by state or local governments which decide which properties to buy [6, 8]. This decision is restricted by federal requirements associated with received funding. The primary sources of federal funding are FEMA’s Hazard Mitigation Grant Program (HMGP) and the Department of Housing and Urban Development’s (HUD) Community Development Block Grants (CDBG) and CDBG-Disaster Recovery (CDBG-DR) program. Each source has its own restrictions, relating to: how much of the project can be funded; what can be done with the area from which people are moved; and whether some of the funding has to benefit low-moderate income groups (see table 1). HMGP and CDBG-DR only become available after a disaster [6].
So what do homeowners receive in exchange for moving? According to the US Constitution, the government cannot take a person’s property without providing “just compensation”. In these programs, this is interpreted as the fair market value (FMV): “what the homeowner would reasonably expect to receive if they sold the home on the private market” [9]. The FMV can be pre-disaster (possible with both FEMA and HUD) or post-disaster (only possible with HUD) [6]. One is not necessarily higher than the other, depending on post-disaster demand and any improvements done to the property. The valuation is done by an appraiser and can take several months [9].
And where do people go after? There is no systematic effort by these programs to track relocations. Relocation assistance can be provided (e.g. funding or building new apartments) but this is not required for voluntary participants [9]. Unfortunately, even after relocation, people can still be in a flood-risk zone. After the superstorm Sandy (2012), 20% of the relocated residents from Staten Island (New York) moved to a flood-risk zone [10].
So what about wildfires, the other major climate risk in the US? Buy-out programs, like described above, have only been recently implemented for wildfire events in 2025, but only in California. [11] However wholesale moving (i.e. moving an entire community) has not been implemented anywhere yet. Some local communities have tried to develop their own program but with limited success [12]. On the contrary, there is even a net influx of people moving towards fire-risk zones [13].
Justice concerns
There are two main concerns here. First, HMGP eligibility requires that repairs would cost more than 50% of pre-disaster value. Secondly, in some cases, the owner may choose to rebuild if alterations are made. But these can be very expensive thereby forcing homeowners to accept the “voluntary” buy-out. Both issues lead to low-income households more likely to accept the buy-out than wealthier households, enhancing social inequity. 3 The method to choose which homes to acquire is often based on cost-benefit analysis (CBA) which in itself promotes inequality. Wealthier neighbourhoods have more “value” (benefits) than poorer neighbourhoods. Therefore, flood protection is more likely to occur in richer areas, leaving the poorer areas vulnerable and more likely to retreat [6]. For example, a project in Cedar Rapids (Iowa) to build levees to protect low-value houses was rejected due to the benefits of protection not outweighing the costs of construction [14].
But, since lower-income groups are most vulnerable to floods, not relocating them specifically may also be considered to exacerbate inequalities. CBA avoids the necessary discussions and justice should be considered explicitly in such programs [6].
However, contrary to previous studies, a 2019 study of FEMA buy-outs from 1989-2017 of 40 thousand homes, found that they largely occurred in richer areas, which possibly indicates some barriers in terms of institutional capacity for poorer areas. With counties however, the study did find that buy-outs were more frequent in relatively poorer areas with lower education levels and greater racial diversity [8].
Conclusion
As climate impacts worsen, adaptation becomes increasingly important [1]. While managed retreat may be inevitable in some cases, the method of implementation is crucial to successful adaptation. This requires an explicit consideration of climate justice into decision-making [5]. The US has a history of injustice regarding relocations [15]. It should do better this time.
