As we grapple with the aftermath of Hurricane Florence in the Mid-Atlantic and Southeast, it’s clear that our development choices contributed to the staggering damages — estimated to be between $17 billion to 22 billion — of this extreme weather event. Now that the rain has subsided, the destruction to houses and buildings in Hurricane Florence’s path is all that remains.
Mostly, though, we're stuck with a harder question: What to do before the next storm to prevent such losses?
One solution is strategic retreat: moving out of harm’s way. As seas rise, flooding is becoming almost a weekly occurrence in cities up and down the East Coast. Wilmington, North Carolina now is subject to chronic tidal flooding due to sea level rise. As storms grow stronger, so are the calls to walk away from the most flood-prone places.
For many, the notion of retreat brings to mind post-apocalyptic visions of empty highways, rusty skeletons of buildings, and houses grown over with weeds. It’s daunting. But scenarios that involve retreat don’t need to be. Innovative thinking about the role of relocation can foster cohesive, rich communities as some move to safer, higher grounds.
We have studied applications of strategic retreat in 22 countries, from the US to Mozambique to Fiji. The process of moving out of harm’s way has taken many different forms — from a few households to whole communities, before and after disasters, and in response to earthquakes, floods, and hurricanes. We found that moving to safer ground can be an attractive option for many reasons: It protects livelihoods, restores coastal ecosystems, and reduces damages from extreme weather.
But the potential of strategic retreat remains largely untapped, even though sea level rise threatens to inundate 4 million to 13 million Americans this century. North Carolina alone is home to 1,132 “severe repetitive loss properties” worth $280 million — properties that, on average, flood every two to three years and have been rebuilt five times with the help of taxpayer money.
Perhaps it’s time to think more about how the government could purchase some of the homes flooded by Florence and restore those properties to open space.
New seawalls can help, but retreat should be part of our planning
Moving to safer ground will be just one strategy among many: We’ll need sea walls in some places, stricter building codes in others, and a change in where new subdivisions, highways, and hospitals are built. Attacking global warming must be part of the solution: Continued emissions of heat-trapping gases drive up the risk of rising seas.
We can’t build our way out of this. Estimates suggest it would cost $400 million to improve stormwater drainage in Miami Beach, at least $8 billion to build floodgates around Houston, and north of $12 billion to barricade New York City. Barring a dramatic increase in resources, we simply cannot block out water at every turn.
Before we look to the future, it’s useful to consider the forces that brought us where we are today. Local governments — especially in states with no income tax, like Florida — rely heavily on property taxes. That creates a strong motivation to let development occur with as little governmental interference as possible. Then when disaster strikes, it is the federal government that foots most of the recovery and relief bill. Development benefits local and state governments and private parties in the short term; the federal government is exposed to the growing risk.
The US government is not unaware of the problem. With support from FEMA's Hazard Mitigation Grant Program, hundreds of communities have spent tens of millions of dollars each year to purchase flood-prone properties from willing sellers. Harris County has purchased more than 3,000 floodplain homes since 1985. These investments save about $4 for every dollar spent, making them a sound federal investment.
What’s blocking us from better-managed retreat from the shore
But the program already faces limitations, ones that will only be magnified as sea levels rise and the potential value of strategic retreat grows. The program's current capacity doesn't meet existing demand from homeowners, much less demand from millions more who may be displaced. What’s more, some people who'd like to make use of the program cannot, because the amount they’d receive for their current home wouldn't be enough for them to move anywhere else nearby. And all of these buyouts are voluntary, so this version of strategic retreat can end up instead as an awkward patchwork of houses and empty lots.
Most importantly, the buyouts are rarely accompanied by a coherent land use plan. Consider Staten Island after Superstorm Sandy (where 20-foot waves reached third-story windows in some neighborhoods). Many homeowners whose properties were damaged or destroyed were interested in selling their homes.
The city government was hesitant to give up residential land, so the state government stepped in to administer the FEMA buyout program. But as a result of financial constraints and the city’s reluctance, the option to participate in FEMA's buyout program was only extended to a select few. Instead, many of the surrounding neighborhoods were given the option of selling to the city of New York. Why does that matter? Under the terms of the FEMA program, properties purchased cannot be redeveloped in the future.
Homes sold to New York City, on the other hand, were auctioned off for redevelopment. So while some houses were taken down for good, others were rebuilt larger than ever. Adding to the chaos, the Army Corps of Engineers is set to construct a sea wall around much of the area — empty parcels, brand new homes, and all. The cost: $579 million, two-thirds of which would come from the federal Sandy aid bill that passed in 2013. That certainly sends a mixed message about the long-term future of the Staten Island waterfront.
Mayors across America are incentivized to keep residents in place and promote growth, and that’s now what shapes our current flood risk management system. The Army Corps of Engineers — the federal agency leading the charge — responds to local requests on a project-by-project basis, lacking any mandate to conduct regional- or national-scale planning. (That must be authorized by Congress.)
But if we invest in more ambitious, coordinated plans, resettlement can deliver much more than peace of mind for the households moving to higher ground. Nearby neighborhoods are made safer as well: Water that used to flow over pavement into the next town can be absorbed into newly open landscapes. In some cases, making space for water can also mean creating urban parks and protecting critical habitat. Governments — that is, taxpayers — can reduce spending on constructing and maintaining infrastructure in flood-prone places.
Communities can start by taking a close look at the most egregious of the repetitive loss properties mentioned earlier. For Florida, a recent analysis identified about 530 such properties across the state in communities with high social vulnerability, significant flood exposure, and high potential for habitat conservation. Whenever relocation is on the table, equity and environmental justice are essential priorities.
From market-priced insurance to buyouts: We should deploy a range of approaches
Fresh strategies for relocation can establish safer ground that will sustain resilient communities for the long term. A flexible approach is key. Buyout programs will still play a role but they will not be sufficient. Market forces can be part of the solution, if insurance is priced appropriately and risk is communicated clearly. For some tight-knit communities, relocating as a group might be the solution.
The need to make room for the floodwaters is especially pressing in South Florida, where even stout seawalls and levees cannot prevent seawater from rising up through the porous bedrock.
The answer is not to build everything back the way it was, before Florence struck, nor is it to buy and demolish every flooded home. It will take a combination of infrastructure reinforcements, elevated homes, insurance policies, and relocation to manage flood risk in a changing climate. Moving out of harm’s way can play a key role in this challenge, but we need to think creatively and strategically about the best way to do it.
Miyuki Hino is a doctoral student in the Emmett Interdisciplinary Program in Environment and Resources at Stanford University. Katharine J. Mach is director of the Stanford Environment Assessment Facility at the Stanford Woods Institute for the Environment and senior research scientist at Stanford. Christopher B. Field is the Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies at Stanford.
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