- As sea-level rise bears down on the West Coast, cities and counties must “overcome the taboo of managed retreat, which in some areas may represent a long-term transformative option,” says an April report by the international Ocean & Climate Platform, which promotes ocean-based climate and biodiversity solutions.
- The practice of relocating people and infrastructure remains contentious and has led to political conflict, notably over potential tax revenue loss for cities, the report says. It adds that communities are still primarily preventing coastal erosion with physical “armoring” such as seawalls, but there is a growing interest in nature-based solutions such as restoration of oyster reefs and wetlands.
- Cities and counties also need to collect locally relevant information, build trust with and engage communities and create flexible, phased adaptation plans, the report says.
By the end of the century, sea levels along the West Coast could rise two feet and an additional 1.6 feet under a high emissions scenario, according to the National Oceanic and Atmospheric Administration. In 2050, flooding is expected to occur ten times more frequently than today, says the report, which is based on 26 expert interviews as well as a September 2022 workshop in Santa Cruz including elected officials, scientists, nonprofits and consultants.
Along with highlighting leading practices for local governments looking to address sea-level rise, the report calls for a reframing of the debate around managed retreat, suggesting alternative terms such as “corrective shoreline planning,” “managed realignment,” “community-led relocation” and “planned relocation.”
Managed retreat can allow communities to “rethink the intersection of built and natural spaces and to conceive better amenities and urban spaces for coastal communities,” as long as the retreat is anticipated, consented to and integrated in phased and flexible manners in adaptation planning, the report says. It points to the California Coastal Commission and Caltrans relocation of several sections of state highway, which enabled shoreline restoration and the creation of visitors’ facilities.
Managed retreat and nature-based solutions have “important synergies” because development relocation provides the space needed to recreate natural systems, said University of California Santa Cruz researcher Borja Reguero in an interview.
Communities are not yet at the “tipping point” where they are consistently considering nature-based solutions, but “we ought to get there,” said Michael Beck, director of the University of California Santa Cruz’s Center for Coastal Climate Resilience, in an interview. “Whenever there is some sort of benefit-cost analysis or assessment of different options, a nature-based option should always be in there,” he said.
It is urgent for communities to begin considering managed retreat soon because the longer they wait, the more expensive it will be, the report says. In Kivalina, Alaska, for example, estimated costs to relocate the town’s 400 residents are increasing each year, potentially ranging from $100 million to a million-dollars-per-person price tag of $400 million, according to the U.S. Climate Resilience Toolkit, which centralizes information from across the federal government.
Beck, however, is uncertain managed retreat will come to fruition in more developed areas, particularly those with high-value homes. “We can debate whether or not we think that's right, but I think when you kind of work through the cost-effectiveness of such a strategy, it's going to be hard for folks to accept that one,” Beck said.
Managed retreat is more than a physical movement of people, he said — it has socioeconomic impacts, as the people displaced must find somewhere else to live.
The report is not blind to these financial realities, saying that the California “coastline simply remains too financialized, and properties retain too much economic value,” which pits interest groups “against the very reality” of sea-level rise. Some West Coast communities already struggle with housing availability, and relocation efforts should give special consideration to less wealthy households to ensure affordable homes remain available locally, the report says.
It recommends policies that make properties’ risk information readily accessible, such as mandated disclosure of risk status and flood history as well as community-level information about future risks. New residential and commercial buildings in flood-prone areas should also be required to be further from the coastline, it says.