{"id":2266,"date":"2018-08-01T09:49:55","date_gmt":"2018-08-01T13:49:55","guid":{"rendered":"http:\/\/lifeaftercarbon.net\/?p=2266"},"modified":"2018-08-02T09:00:34","modified_gmt":"2018-08-02T13:00:34","slug":"can-it-happen-here-managed-retreat-for-us-cities","status":"publish","type":"post","link":"https:\/\/in4c.net\/2018\/08\/can-it-happen-here-managed-retreat-for-us-cities\/","title":{"rendered":"Can It Happen Here? Managed Retreat for US Cities"},"content":{"rendered":"

Update for an INC project – Feedback welcome!<\/em><\/strong><\/p>\n

For several months John and I have been studying what’s known and done about “managed retreat,” to understand how US cities might be prompted to adopt this ignored strategy for climate adaptation. We’ve developed some initial ideas, a hypothesis, and some framing of the landscape within which decisions about managed retreat are made. And there’s more research and thinking to do. Here’s what we have so far:<\/p>\n

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The typical dynamics of urban development block most US cities from planning\u2014or even considering\u2014a \u201cmanaged retreat\u201d strategy to prepare for climate changes that could cause parts of the city to be uninhabitable or unusable in this century. Retreat– removing development and relocating people, businesses, and infrastructure\u2014would produce a great deal of political, financial, and community pain and little tangible gain in the short run. This is true even in cities that have undergone a horrendous climate disaster; their instinct is to rebuild their development\/spatial footprint, perhaps protecting it more, but not adjusting its expanse to avoid future risks.<\/p>\n

And yet, climate changes are projected to make parts of many cities inhabitable and unusable during this century. Rising sea levels and more frequent and intense rainfall will cause chronic flooding and erosion in coastal and riverside communities. By 2060, more than 270 coastal US communities will be chronically inundated, given moderate sea-level rise, according to a 2017 study by the Union of Concerned Scientists. More rapid sea-level rise could chronically inundate nearly 670 coastal communities by 2100, including 50 heavily populated cities, among them: Oakland, Miami, New York City.[1]<\/a> Prolonged droughts will cause severe water shortages and waves of extreme heat will make it dangerous to be outside. El Paso, Las Vegas, Phoenix, and other cities in the southwest US are located in arid environments that have natural scarcity of water and precipitation and are becoming hotter and drier, a 2017 Arup report noted, adding that the nation\u2019s arid zone is expanding.[2]<\/a><\/p>\n

Cities that do anticipate these climate risks usually plan to build their way out of the problem: build more barriers to sea and river surges, more capacity for storm water drainage and water delivery, and more electricity-generation capacity to power more air conditioners to cool buildings. They also plan to move out of climate-harm\u2019s way any underground and street-level infrastructure that could be inundated.<\/p>\n

Only a few US cities have included managed retreat in their plans, and some of these are hardly examples of best practice. In April 2018, California\u2019s Coastal Commission forced Del Mar, with about 4,100 residents, to include a retreat strategy in its coastal resilience plan or lose local authority over future development.[3]<\/a> New Orleans started a retreat strategy (property buy outs) after Hurricane Katrina, but then abandoned it. The US Army Corps of Engineers included retreat\u2014\u201creal estate acquisition and\/or relocation\u201d\u2014in its October 2017 flood management recommendations for coastal Norfolk, Virginia, along with many structural defenses, but the overall plan\u2019s $1.8 billion price tag is bigger than the city\u2019s annual budget and depends in large part on receiving a special federal appropriation.[4]<\/a><\/p>\n

In view of this situation, the Innovation Network for Communities is creating a framework to help answer this question: how can managed retreat become a general planning practice of US cities? The framework redefines managed retreat, describes four pathways that can lead cities to choose to retreat, and identifies the city capacities needed to prepare, implement, and defend decisions about which pathway(s) to managed retreat are being taken. It examines an initial hypothesis: that market dynamics are the most likely force that will lead cities to consider and embrace managed retreat. And it proposes several next steps.<\/p>\n\n\n\n
An Initial Hypothesis<\/strong><\/p>\n

Based on initial research, our hypothesis is that city consideration of managed retreat may follow any or a combination of four pathways, each of which has different instigating actors and approaches to retreat, with different implications for what a city will have to deal with. The pathways are:<\/p>\n

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  • Rational Planning<\/strong>. City government officials engage in a typical planning process focused on addressing climate risks; the process surfaces the option of and articulates the case for managed retreat.<\/li>\n
  • Market Dynamics<\/strong>. Developers, property owners, insurers, financial institutions, and other economic interests respond to climate risks in ways that result in property abandonment, climate migration\u2014a piecemeal and unmanaged retreat that the city decides to address. \u00a0<\/span><\/li>\n
  • State\/Federal Policy Mandates. <\/strong>State and federal governments require city governments to plan retreat and\/or take retreat actions, or limit cities\u2019 non-retreat options in addressing climate risks.<\/span><\/li>\n
  • Community Organizing<\/strong>. City residents, businesses, and\/or institutions voice concerns about climate risks and press governments, starting locally, to respond, including to support managed retreat if necessary.<\/span><\/li>\n<\/ul>\n

    The Market Dynamics pathway appears to be the one most likely to be taken in many cities\u2014with distinct implications for what cities will need to do.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Defining Managed Retreat<\/strong><\/p>\n

    Most literature and news reports about managed retreat focus on the elimination of existing physical infrastructure and housing and the subsequent relocation of people due to retreat-inducing threats posed by flooding due to rising seas and rivers. For research purposes, we have framed managed retreat more broadly in two ways. Our definition includes the prevention of future <\/em>development, not just the dismantling of existing<\/em> development, because relinquishing development is also a consequential retreat from a city\u2019s future land-use footprint. And we have considered the climate risks that, in addition to chronic flooding, may be posed by extreme heat and drought as another potential driver of city retreat.<\/p>\n

    \u201cManaged retreat\u201d is the use of public policies, including regulation and investment, to over time eliminate or prevent development from areas that are:<\/p>\n