A.R. Siders and Katherine Mach: As coastal flooding worsens, cities beating strategic retreat

When the tide gets exceptionally high in Charleston, South Carolina, coastal streets start to run with seawater. Some yards become ponds, and residents pull on rain boots.

After homes in one low-lying neighborhood flooded three times in four years, the city offered to buy out 32 residents and turn their land into open space that can be used for managing future floodwater. It’s a strategy coastal cities from Virginia to California are increasingly contemplating as tidal flooding increases with rising sea levels.

Cities all along the U.S. coasts have seen high-tide flooding days increase. The U.S. coasts are currently averaging 3-7 tidal flooding days a year, but the rate is projected to rise to 25-75 by mid-century, according to the National Oceanic and Atmospheric Administration.

Low-lying Charleston saw a record-breaking 14 days of tidal flooding in 2020, and parts of the city counted even more.

The city is considering new sea walls to protect against hurricanes, and other measures to try to keep tidal and storm flooding out of threatened neighborhoods. But it has also started helping resident relocate away from high-risk areas.

The strategy is known as “managed retreat.” It’s the purposeful movement of people, buildings and other infrastructure away from highly hazardous places.

Managed retreat isn’t just about moving. It’s about building communities that are safer, addressing long-overlooked needs, incorporating new technologies and pursuing thoughtful design for today’s world.

We argued in a piece in the journal Science that managed retreat represents an opportunity to preserve the essential while redesigning high-risk areas in ways that are better for everyone.

Marine Corps Gen. Oliver P. Smith famously said of a retreat he led during the Korean War: “Retreat! Hell! We’re just advancing in a different direction.” Like Gen. Smith’s maneuver, retreat from climate change-related hazards is, at its core, about choosing a new direction.

Managed retreat could involve turning streets into canals in coastal cities. It could mean purchasing and demolishing flood-prone properties to create open spaces for stormwater parks that absorb heavy rains or retention ponds and pumping stations.

In some cases, it may involve building denser, more affordable housing that’s designed to stay cool, while leaving open spaces for recreation or agriculture that can also reduce heat and absorb stormwater when needed.

Managing retreat well is challenging, though.

Soldiers Grove, Wisconsin, relocated its flood-prone business district in the late 1970s. It used the opportunity to heat the new buildings with solar energy, earning the nickname “Solar Village.”

The move reinvigorated the local economy, but some residents still miss the old town.

Since high-risk areas are often home to Black, Indigenous and low-income communities, addressing climate change in these areas may also require addressing a national legacy of racism, segregation and disinvestment.

At its simplest, managed retreat can be a lifeline for families who are tired of the emotional and financial stress of rebuilding after floods or fires, but cannot afford to sell their home at a loss or don’t want to sell and put another family at risk.

Even if an individual or community decides not to retreat, thinking critically and talking openly about managed retreat can help people understand why remaining in place is important, and what risks they are willing to face in order to stay. Thinking carefully about what parts of our lives and communities should stay the same opens space to think creatively about what parts should or could change.

From The Conversation, an online repository of lay versions of academic research findings found at https://theconversation.com/us. Used with permission.


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