Relocation and Innovative Solutions for Managing Future Flood Risk

Relocation and Innovative Solutions for Managing Future Flood Risk

Alex Score
Time Slot: 
Concurrent Sessions 4
Session Type: 
Tools and Posters

This session concerns different policies and solutions for managing flood risk in a changing climate. It starts by outlining experiences with and outcomes of the FEMA buyout program, the largest form of managed retreat implemented in the US to date. Two proposals for future solutions follow, one builds on the existing buyout program, and the other focuses on innovative community involvement. The session concludes by showing ways to bridge the science-policy divide for sea level rise assessments. Equity and social justice will be a major theme throughout.


The landscape of voluntary property buyouts to manage flood risk in the United States
Carolien Kraan, Stanford University
  • Katharine J. Mach, Stanford University
  • Miyuki Hino, Stanford Unversity
  • A.R. Siders, Harvard University
  • Erica M. Johnston, Stanford University
  • Yi-Lin Tsai, Stanford University
  • Christopher B. Field, Stanford University
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Managed retreat from flood-prone areas is an increasingly important adaptation option for reducing risks to people and assets. Learning from experiences to date, such as long-running property buyout programs in the United States, is essential for informing future deployment. Since 1989, the U.S. Federal Emergency Management Agency (FEMA) has funded voluntary buyouts of over 40,000 flood-prone properties, with the land subsequently maintained as open space. Here, we analyze where buyouts have occurred with respect to flood risk, socioeconomics and demographics, and local capacity. The evaluation is attuned to adaptation effectiveness and equity. Buyouts have taken place in almost every U.S. state, yet approximately half are concentrated in fewer than 10 states and in program years 1989–1998. The number of bought-out properties in a single county ranges from 1 to 2190 (median=11), implemented through 1–59 grant projects (median=2). Buyouts have been concentrated in more flood-prone areas, as measured by disaster declarations, property damage, and flood hazard, and bought-out properties are largely single-family homes and primary residences. Results suggest that capacity of local governments has enabled participation in the FEMA buyout programs, yet bought-out properties are concentrated in areas of greater social vulnerability, pointing to the importance of assessing the equity of buyout implementation and outcomes. Deployment of buyouts has been more likely in counties with higher population and income, in contrast to model-based analyses of managed retreat under increasing sea level rise. Improvements, such as more consistent project reporting, could catalyze learning in the policy process through time.

Case studies of community relocation and managed retreat policies in U.S. floodplains
A.R. Siders, Harvard University
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Managed retreat, the removal of infrastructure in vulnerable floodplains and relocation of communities, is a controversial strategy for adapting to the increased risks posed to riverine and coastal communities by global climate change. However, there is growing recognition that protecting communities in place will not always be possible and some relocation may be necessary. How can retreat be done effectively and equitably? Managed retreat has the potential to end cycles of destruction and rebuilding that leave some communities “trapped” in risky areas, but retreat has also been shown to cause social, economic, and psychological harm to participants, and in the United States it is likely to disproportionately affect low-income and minority communities, potentially exacerbating historic inequalities. However, these outcomes, both beneficial and harmful, are not foregone conclusions. How retreat is performed – which laws and policies are used and how they are designed and implemented – can have a significant effect. Drawing on case studies of managed retreat policies in New England and Mid-Atlantic states, this talk presents preliminary results from an ongoing study into how retreat policy design and implementation affect social equity, economic resources, risk reduction, and ecological restoration outcomes. Cases include policies such as property acquisition, setback building restrictions, rolling easements, and eminent domain condemnations. Results identify specific challenges of retreat, strategies used by communities to overcome those challenges, and information gaps that need to be addressed to inform future retreat efforts. Audience questions and feedback will inform subsequent phases of this ongoing project.

Flood, Rebuild, Repeat
Rob Moore, Natural Resources Defense Council
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In the U.S., flood insurance is usually the only timely assistance owners of repeatedly flooded homes can access easily, but it generally pays to rebuild in the same vulnerable location. For homeowners who want to move, escaping the threat of sea level rise, assistance is hard to find. The U.S. spends relatively little to help people move out of harm's way, even though helping people relocate is often cheaper than rebuilding. When assistance is offered, it can take years of waiting.

More than 30,000 "severe repetitive loss properties" have flooded an average of five times and the U.S. spent $5.5 billion to rebuild these homes. NRDC estimates that sea level rise will place up to 2.57 million homes in an identical situation by century’s end, with the U.S. spending as much as $447b to repeatedly rebuild. NRDC has developed a proposal to pre-approve interested low-income homeowners and guarantee them a future buyout, breaking the cycle of flood, rebuild, repeat and eliminating the years long waiting and uncertainty common to current efforts.

Public Sediment Overview + Moderator
Gena Wirth, SCAPE Landscape Architecture
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Planners are working directly with local communities to lead the design of ecosystem-scale projects that address emerging climate change threats and prioritize social equity and access. This session reveals new methodologies for the co-design of large-scale ecological infrastructure that addresses sea level rise threats in the San Francisco Bay area. The design process for Public Sediment for Alameda Creek will be featured as a case study, and will be presented through the perspective of a community advocate, an agency stakeholder, and a design team member.

Public Sediment was developed for the Resilient by Design Bay Area Challenge, a design competition that brings together local residents, public officials, and local, national and international experts to develop innovative solutions to the issues brought on by climate change in the Bay Area. Public Sediment for Alameda Creek is a proposal to address the challenge of sediment scarcity along the vulnerable urban edges of Fremont, Union City, and Newark, California. The proposal provides a sustainable supply of sediment to baylands for sea level rise adaptation, reconnects migratory fish with their historic spawning grounds, and introduces a network of community spaces that reclaim the creek as a place for people.

Bridging the Science-Practice Divide: Washington’s Sea Level Rise Planning Toolkit
Harriet Morgan, University of Washington Climate Impacts Group
  • Ian Miller, Washington Sea Grant
  • Guillaume Mauger, University of Washington Climate Impacts Group
  • Nicole Faghin, Washington Sea Grant
  • Crystal Raymond, University of Washington Climate Impacts Group
  • Heidi Roop, University of Washington Climate Impacts Group
  • Robert Norheim, University of Washington Climate Impacts Group
  • Tish Conway-Cranos, Washington Department of Fish and Wildlife
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As part of the NOAA-funded Washington Coastal Resilience Project (WCRP), the Climate Impacts Group, Washington Sea Grant, and partners released an updated sea level assessment for Washington State. This assessment incorporates probabilistic sea level rise (SLR) models, accounts for variations in vertical land movement, and improves our understanding of coastal hazards.

While the best available SLR science is essential for increasing climate resilience in coastal communities, projections alone are insufficient to support effective climate adaptation. This is demonstrated by the fairly limited number of adaptation projects implemented across Washington, despite a history of regional SLR assessments.

In order to bridge this science—practice divide we developed a suite of tools to help planners and communities interpret and apply these SLR projections in a planning context: (1) a “How to Choose” framework that helps decision-makers identify the appropriate timeframe, greenhouse gas scenario, and risk tolerance that should be considered when evaluating projections for a specific project; (2) guidelines for mapping SLR inundation using the localized projections; and (3) a considerations document for incorporating the projections into nearshore restoration projects.

Local decision-makers need more than just data to make resilient decisions in the face of SLR. This toolkit was designed to facilitate the incorporation of SLR projections into local planning and management contexts by improving decision-maker understanding of the projections. This presentation will showcase the lessons learned from co-producing this toolkit and highlight next steps in the project as we seek to apply these frameworks to develop a library of case studies.