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Brent Doberstein
Department of Geography and
Environmental Management
Introduction
‘Managed retreat’ is gaining attention as an option for climate change adaptation (CCA) or disaster risk reduction (DRR) planning in coastal megacities. Coastal megacities are at particular risk to climate change hazards such as sea-level rise, coastal erosion, storm surges, flooding and landslides. Managed retreat, or the planned relocation of homes and infrastructure threatened by coastal hazards, is one of four main options included in the protect-accommodate-retreat-avoid (PARA) framework used to enhance resilience in coastal megacities (Figure 1).
Figure 1: The PARA framework of resilience-building through exposure reduction
The primary goal of this research was to assess the feasibility of using managed retreat in two case study coastal megacities: Manila, Philippines, and Vancouver, Canada. Case studies were used to identify current CCA/DRR policies linked to managed retreat and highlighted managed retreat practices and barriers to managed retreat. Suggestions as to how to overcome barriers to using managed retreat as a CCA/DRR strategy were provided.
Methodology
The research employed a qualitative, comparative case study method using primary and secondary data sources. Primary data were derived from semi-structured key informant interviews in Vancouver (N = 27) and Manila (N = 27). Interviewees in Manila included resettlement and CCA/DRR professionals from international agencies, national and local governments, private and non-governmental sectors, community organizations and academia. Interviewees in Vancouver included flood management and coastal adaptation professionals from private sector engineering and consulting firms, policy and research institutions, and provincial and municipal governments. Interview responses were analyzed for expected and emergent themes using NVivo software. Secondary data sources included published journal articles, local newspaper articles, government web pages, and grey literature reports.
Outcomes
Metro Manila is surrounded by coastal, lagoon and riverbank flood risks. Many of Manila's riverways are lined by informal settlements that have a high vulnerability to environmental threats due to their physical location, hazard exposure and social vulnerabilities. Recent extreme storms have identified the need for a CCA strategy, for example by incorporating actions into existing resettlement schemes.
Photos of informal settlements in Manilla by Brent Doberstein.
Land availability is a key barrier to managed retreat in Manila. Dense and sprawling urban development makes it a challenge to find available, affordable, environmentally safe, and desirable land for resettlement within the city. Social and livelihood risks are also a barrier, with many residents working as part of the informal economy and preferring to remain close to their urban livelihoods rather than relocating to distant areas. Jurisdictional conflicts among Manila’s 16 cities, a lack of political will, and government corruption also pose challenges to proactive planning such as managed retreat for climate change.
Metro Vancouver is projected to be faced with environmental hazards from climate change including sea level rise, increased coastal, riverine and urban flooding and landslides. Although managed retreat is identified as a policy option in Provincial planning documents, specific retreat policy is underdeveloped. In practice, managed retreat has been infrequent and not implemented in response to long-term threats, with home buyouts being used on a small-scale basis linked to DRR. Coastal adaptation plans and actions in Metro Vancouver have prioritized protect structural measures such as dikes and seawalls. Results suggested that protect was the favoured approach since it is the “least expensive” and “least disruptive” approach in comparison to managed retreat which was seen as expensive and unfamiliar.
Land affordability/availability was identified as a key barrier to managed retreat in Vancouver. Results noted that introducing a SLR retreat zone along the waterfront would come at high cost to taxpayers while reducing real-estate investment, land-values, and economic development opportunities. A jurisdictional mismatch/conflict of responsibility among federal, provincial and local governments for adaptation within at-risk areas was also identified as an important barrier. Political will, with politicians unwilling to make long-term adaptation decisions where public support favours immediate solutions such as engineered structures, was an additional barrier. Social and livelihood risks of managed retreat, such as displacement of people and communities, were also identified as obstacles. Results suggested that retreat would likely be a top-down and immediate risk reduction strategy in the aftermath of a disaster, with the majority of the government and financial backing provided by provincial and federal levels.
The study argues that the future hazard implications of climate change are sufficient to warrant the consideration of managed retreat as a CCA/DRR option in both case study cities, but that each city should understand its ‘hazardscape’ before deciding what role, if any, managed retreat has in local plans. Policies which provided support for managed retreat were found in both cities, with Vancouver having the most supportive policy environment and Manila having made significant investments into resettling informal settlement families away from rivers. Several differences related to managed retreat policy or practice were noted. For example, managed retreat policies apply in Vancouver to both the relocation of people and infrastructure, while in Manila policy applies primarily to people, and while lack of funding has hindered managed retreat in Vancouver, significant funds have been committed in Manila. Despite significant contextual differences in the two cities, the research revealed similar barriers to the use of managed retreat (Table 1).
Table 1. Barriers to managed retreat as a CCA/DRR strategy.
|
Barrier: general category |
Manila |
Vancouver |
|---|---|---|
|
Land Availability and Affordability |
2 |
3 |
|
Political Will |
2 |
3 |
|
Social and livelihood risks |
3 |
3 |
|
Jurisdictional Conflict |
1 |
2 |
|
Funding |
0 |
3 |
|
Corruption |
3 |
0 |
0 = non-barrier (0% of interviewees indicated this was a barrier).
1 = weak barrier (1–10% of interviewees indicated this as a barrier).
2 = moderate barrier (11–30% of interviewees indicated this as a barrier).
3 = strong barrier (>30% of interviewees indicated this as a barrier).
Conclusions
The research reinforced the importance of including managed retreat as one of the resilience-building options of the PARA framework and identified key barriers that can block its use. It argued that strengthened political will and improved policy support and leadership is critical if the approach is to form part of a megacity's climate change CCA/DRR ‘toolbox’. Barriers to managed retreat can be addressed through municipal or regional policies, updates to municipal CCA/DRR guidance documents, documenting successes in small pilot projects, and through new or expanded CCA/DRR funding mechanisms. Jurisdictional conflicts and social and livelihood concerns suggest that a multi-stakeholder engagement approach should be used to design solutions that are coordinated across multiple municipal jurisdictions, and involve public, private and third sector stakeholders. Making an economic case for managed retreat will require that megacity planners calculate the climate-change-adjusted costs of a wide range of CCA/DRR approaches.
The study noted that contexts for managed retreat vary significantly between developed and less developed nations for a variety of reasons, including that in developed nations homeowners with coastal properties are often wealthy and have access to political and legal support, in contrast to the developing nations where those living in at-risk areas are often poor. In Vancouver, concerns surrounding the right of governments to forcibly remove landowners for environmental purposes appeared to be a powerful barrier to managed retreat, while in Manila social and environmental justice concerns focused on the post-relocation livelihoods of poor communities.
Read more in Journal of Environmental Management
Doberstein, B., Tadgell, A., Rutledge, A. Managed retreat for climate change adaptation in coastal megacities: A comparison of policy and practice in Manila and Vancouver. Journal of Environmental Management, Volume 253, 2020.
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