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Coastal Properties and Climate Change: Managed Retreat May Be the Best Option

Around 8% of the U.K.’s population is at risk of flooding. In many areas structural flood defences protect households and businesses from flooding but only up to a certain threshold. If the flood is big enough it overwhelms defences leading to catastrophic events such the North Sea Storm Surge of 1953 in the U.K. and the Netherlands or more recently Hurricane Katrina in the US.

With climate change exacerbating flood risks, flood defences will not offer the same level of protection as they used to unless they are reinforced. Particularly coastal communities across the U.K. face an unprecedented challenge to adapt to these increasing flood risks due to rising sea levels increasing the risk of storm surges. One of the inconvenient truths of this adaptation process is that for many communities, the only affordable, technically feasible and fair, long-term adaptation option will be moving to a less flood prone location — also known as “managed retreat.”

As one of the headline topics of almost every report on climate change from the IPPCC Assessment Reports to the National Climate Assessment in the U.S. or the U.K. Climate Change Risk Assessment, as well as at every COP over the last decade (including the infamous speech of Tuvalu’s foreign minister at COP26 standing knee-deep in water), the discourse on managed retreat and relocation is almost as old as the discussion on climate change itself. While it makes a strong and compelling narrative for climate action, the discourse has so far remained an abstract one.

Shoreline management plans in the U.K. and elsewhere remain vague when it comes to managed retreat, referring to uncertainties in climate projections and delegating the decision if and/or when to retreat to local authorities arguing that they are in the best position to decide what needs to be done.

However, managed retreat is understandably not a popular topic for local politics in at-risk communities. 

Behavioural studies on how households respond to flood risk show that most people tend to not take flood risk seriously until it materializes.

Relocating entire communities, aside from being a rare and unusual process, poses a threat to some of the core principles of human settlements, such as their geographic location and territorial integrity as well as some fundamental human rights, such as the right to property. Not to mention the loss of some of the amenities that waterfront properties offer. Nevertheless, if decision-makers on any level want to take the “managed” in “managed retreat” seriously, there is no time to lose for many communities across the U.K.

The Risk of Last-Minute Decisions

A recent study by Sayers et al. (2022) reviewing shoreline management plans in England, suggest that around 1600-1900 kilometres of English coastline where the current adaptation option is ‘holding the line’, will likely get under pressure by the 2050s leading to 120,000-160,000 properties facing uncertainty whether there will be continued protection or whether they will need to relocate.

In face of the scale of the challenge and despite all valid concerns and local resistance against managed retreat, there are a number of reasons why waiting until the last minute to decide on relocation should not be the preferred option.

First, relocation takes time. A popular relocation strategy, especially in the US, are buyout programs, in which governments buy at-risk properties to either demolish homes or relocate them. This is a complex process with legal and political battles being the norm rather than the exception. There are many examples of individuals refusing to move despite the evidence of their property being in an unsafe location and managed retreat programs going badly. 

The example of the town of Marina on the California coast shows why starting the process early pays off. The town’s sea level rise plan has been passed with little resistance as it sets a clear timeline over the coming decades outlining when specific buildings must move, giving residents enough time to prepare for a life at a different location. Their plan also defines clear priorities such as ensuring public beach access and setting a clear vision for the relocated town, namely “a desirable residential and business community in a natural setting”.

Chaotic Relocation

Second, the risk of flooding is inherently probabilistic, meaning that while we can quantify with some uncertainty the probability of a flood event occurring, we cannot predict when a flood will happen. The ‘big one’ can come tomorrow or in 20 years from now. Behavioural studies on how households respond to flood risk show that most people tend to not take flood risk seriously until it materializes. A study by de Koning et al. (2019) on the U.S. found that households only consider relocation after they have been flooded. If we wait for this to happen, the relocation process is likely to be chaotic rather than managed. This can lead to severe distortions in the community when those who are able to move after a flood event (usually younger, healthier, and wealthier households) leaving those who rely on external help behind.

Third, trying to become ‘too big, too fail’ is a risky bet for many communities. Creating a healthy competition between local authorities to attract new investments, new jobs, and subsequently new people in need for housing is generally seen as a good thing that allows communities to develop. 

However, a recent study on England and Wales has shown that in many cases, this is done in a way that results in more homes being built in areas at risk of flooding and disproportionately in disadvantaged neighbourhoods and communities. Having more properties at risk of flooding can mean that chances to receive national funding for flood alleviation schemes are increasing, but in case a community does not make the cut, those who cannot afford to count their losses and leave will likely be left behind (see previous point). 

Fourth, insurance can soften the impacts but cannot fix the problem. With FloodRe, the U.K. has a reinsurance solution that, by pooling and through a levy paid by insurers, ensures that flood insurance for properties at significant risk of flooding is available and affordable. 

However, FloodRe is designed to be transitory to give private households, local and central government time until 2039 to reduce the risk to an extent that ensures flood insurance remains affordable before it is phased out to become a free market. Those households whose risk has not reduced or even increased (for example, because new protection measures are not affordable or technically feasible) will likely face a steep cliff once FloodRe ends.

The clock is ticking for many at-risk communities in the U.K. (and elsewhere) as even if flood risks look manageable today, there is no guarantee they will be in the future. While this makes for some unpleasant conversations it will certainly make things easier if we have them now than later.

Viktor Roezer

Research Fellow at the Grantham Research Institute on Climate Change and the Environment, London School of Economics

Viktor joined the Grantham Research Institute on Climate Change and the Environment in December 2018 as part of the Zurich Flood Resilience Alliance (ZFRA) project. He works on adaptation and resilience to flooding and other climate related risks with a focus on urban areas. He is interested in the quantification of flood impacts, the role of insurance and incentives for increasing pre-event resilience.

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