New Paper Argues for Managed Retreat from Flood-Prone Areas

Flooding in Port Arthur, Texas after Hurricane Harvey, August 31, 2017. In a new paper, researchers argue for a managed retreat from flood-prone areas.

Flooding in Port Arthur, Texas after Hurricane Harvey, August 31, 2017. In a new paper, researchers argue for a managed retreat from flood-prone areas. Staff Sgt. Daniel J. Martinez / U.S. Air National Guard

A new paper argues that adapting to climate change over the long term will require managed retreat from areas that are prone to floods or other hazards. While managed retreat has long been viewed as a solution of last resort, authors say that it can be an economically efficient means of coping with climate change.

“Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it,” said A.R. Siders, assistant professor at the University of Delaware Disaster Research Center and co-author of the paper, which was published in the journal Science. “One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked.”

Managed retreat is already underway in some places. After Hurricane Harvey, Houston offered support for coastal homeowners looking to relocate. In California, the state senate recently passed a bill that will help counties and communities buy up coastal homes threatened by rising seas. Authors say that, going forward, such plans should be given serious consideration when weighing how to cope with climate change.

“Managed retreat can be used to address climate risks, along with other types of responses like building seawalls or limiting new development in hazard-prone regions,” said Katharine Mach, associate professor at the University of Miami Rosenstiel School of Marine and Atmospheric Science, and co-author of the paper with Siders.

Retreat will be necessary on the small scale to make room for flood barriers, drainage pipes and other flood-resilient infrastructure, the paper says. And retreat may be needed for more ambitious adaptations. For instance, coastal residents may relocate from flood-prone seaside homes to floating neighborhoods. In Amsterdam, in the Netherlands, some locals are already moving into floating homes that accommodate the tides.

“If the only tools you think about are beach nourishment and building walls, you’re limiting what you can do, but if you start adding in the whole toolkit and combining the options in different ways, you can create a much wider range of futures,” Siders said.