COASTAL CHALLENGESSea Levels Rise and Floods Intensify, So Governments Consider Managed Retreat

By Martin Kuebler

Published 5 July 2022

As climate changes, rising sea levels and disastrous flooding are becoming ever more common, and they could force billions to move during the next decades. Instead of trying to prolong the inevitable by building sea walls, importing sand to build protective dunes and berms, planting mangrove, and raising structures on stilts, some communities are already adapting: They are developing plans to move away from vulnerable areas to higher ground inland.

People have been pushing back the boundary of the sea for centuries. Whether by building dikes in the Netherlands or creating artificial islands with soil and debris in places such as Hong Kong and Dubai, it once seemed as if nothing could stand in the way of our expanding landmass.

But, with rising sea levels and disastrous flooding becoming ever more common, some communities are beginning to consider the opposite approach to counter the effects of climate change: managed retreat.

This could include moving from big cities. In Sydney, Australia, the latest extreme torrential rain has caused dams to overflow and rivers to break their banks, forcing more than 30,000 residents to evacuate. Areas north and south of the city were deluged with 1.5 meters (59 inches) of rain in 24 hours, which is close to the average rainfall for a year in coastal areas of the state of New South Wales, according to Australia’s Bureau of Meteorology.

After Sydney also flooded in April, the premier of the state acknowledged that such extreme weather was “becoming more common,” and it would be necessary to “respond to the changing environment.” 

What Is a Managed Retreat?
Managed retreat means permanently moving people and buildings away from vulnerable areas — either in a preventative way or, as is more often the case, after a disaster. That’s been the case in New Orleans, ever since Hurricane Katrina devastated the low-lying city at the mouth of the Mississippi River in 2005.

Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it,” A.R. Siders, a disaster researcher at the University of Delaware, wrote in a June 2021 study. “One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked.”

In New Orleans, some rebuilding projects have offered low- and middle-income families the chance to relocate to new homes on higher ground, as have buyout schemes in the surrounding state of Louisiana. Similar programs are in place nationwide: As of 2017, the Hazard Mitigation Grant Program run by disaster management agency FEMA had bought up more than 43,000 homes in flood-prone areas across the United States and its territories abroad.

But it’s not always so simple: The process can be complicated by government red tape and end up exacerbating social inequalities as long-established communities are displaced.