When it’s impossible to fight rising sea levels, should we move somewhere else?

San Francisco policymakers consider hotly-contested ‘managed retreat’ strategy

Relocating homes, communities and essential infrastructure away from shorelines may become a reality for low-lying coastal areas where rising tides already are lapping at doorsteps.

But the concept, called managed retreat, has become a hotly contested topic for policymakers and communities for whom a migration away from homes and communities can feel like a latent threat.

Still, experts argue that in some cases, staying put is also untenable. That’s why this week, SPUR, a local public policy nonprofit, is hosting an event that poses the uncomfortable, yet inevitable, question: When, if ever, is the right time to talk about managed retreat?

“The numbers for managed retreat are compelling,” said Nicholas Pinter, professor and associate director of the Center for Watershed Sciences at the University of California Davis. “By many estimates, it’s tens to hundreds of millions of people in the U.S. that may be looking at this in coming decades, and it’s at least hundreds of millions on a global basis.”

As coastal areas face worsening climate threats, it’s become clear that resilience efforts alone will not save us entirely. But encouraging migration away from flood zones and eroding cliffsides is a bitterly divisive subject — especially in the United States where there is a long and fraught legacy of forcing non-white communities off land or property under the guise of progress.

The good news is “managed retreat is a long way off in the Bay Area,” said Laura Feinstein, SPUR’s sustainability and resilience policy director. “But having these conversations now can help us be in a better position to plan for it in the future.”

In the Bay Area, sea levels are projected to rise 3 to 6 feet by the end of this century. Coupled with more extreme weather events as a result of a changing climate, over 6% of San Francisco’s land could be inundated, according to the Planning Department.

This puts more than 37,000 residents, 170,000 jobs and vital infrastructure, including roadways, utilities, emergency services and transit, at risk.

Not always possible

Managed retreat most often is achieved through government buyouts of vulnerable or at-risk properties. The United States has spent more than $5 billion on such initiatives over the past three decades, according to some reports.

But not all retreat is created equal. The towns that have managed successful retreats have tended to be smaller, rural communities with less infrastructure to uproot and more space to rebuild. Places like Fargo, North Dakota, and Birmingham, Alabama, have pulled back from their respective riverbanks.

In a densely populated metropolis like San Francisco, the story is more complicated. “Retreat and avoid are not necessarily going to be feasible everywhere,” said Dana Brechwald, a program manager at the San Francisco Bay Conservation and Development Commission (BCDC), who is working on the agency’s Rising Tides initiative. “I think San Francisco is one of those places, and that’s why they’re investing billions of dollars into rebuilding a sea wall.”

A map showing projected sea level rise vulnerabilities in blue, with 100-year storm surge projections in orange. (San Francisco Planning Department)

A map showing projected sea level rise vulnerabilities in blue, with 100-year storm surge projections in orange. (San Francisco Planning Department)

Regional adaptation in and of itself is a complex tangle of policies, projects and preferences. A sea wall in one place, for example, could have adverse effects on another. Recent research out of Stanford University found the addition of sea walls in certain parts of the Bay could increase flooding for communities throughout the region, costing hundreds of millions in flood damages, and potentially exacerbating the need to relocate.

“Seawalls are sort of the last resort,” said Arthur Feinstein, Sierra Club California executive and longtime conservationist. “The more you put up seawalls, the higher the water — and it becomes the bathtub. You fill it up. It’s got nowhere to go. And so it goes up.”

But despite local projections that show places like Bayview Hunters Point, the Embarcadero waterfront and Treasure Island will be inundated with water under warming conditions, The City continues to develop shiny new skyscrapers, stadiums and multi-story housing close to the shoreline, something that may be unavoidable given housing pressures, but may not be advisable long term.

“We should be looking carefully at placing new infrastructure in the locations most at risk,” said Pinter.

Also complicating matters, managed retreat is not yet officially defined or considered a formal policy by the Bay Area’s planning body, which makes it nearly impossible to track and enforce such adaptation projects on a regional scale.

“BCDC does not have a managed retreat policy,” said Jaclyn Mandoske, a coastal scientist with the agency who serves BCDC in an advisory capacity. “We don’t have any plans to do so.”

Question of equity

Despite this, the question of how to withdraw from shorelines equitably is evidently top of mind, as it raises the questions of who should be protected, who should move, where people could go and who should be left footing the bill.

In the past, managed retreat has not always been a fair and just process, and there are myriad examples of what not to do, said Pinter. Take Grafton, Illinois, which was flooded by the Mississippi River in 1993. “None of the low-income people who were removed moved into the higher-end housing that was made available,” he said. “That was a great case of flood mitigation, but a poor case of social justice.”

In the Bay Area, many of the most vulnerable and heaviest burdened communities live close to the shoreline, which makes this work even more challenging, especially as rising seas infiltrate groundwater, pushing an upwelling of buried industrial chemicals and other pollutants to the surface. It’s a toxic soup that’s poised to flood nearby neighborhoods.

“The biggest climate threat to San Francisco, we think, is the shoreline contamination, sea level rise issue and groundwater rises,” said Bradley Angel, executive director of the environmental justice nonprofit Greenaction, which is demanding San Francisco implement a full-scale clean up of the toxic waste buried in places like Hunter’s Point and Treasure Island.

But San Francisco isn’t alone in hosting a slew of heavy industry along its shores, which makes this a regionwide issue. “Water doesn’t care what boundaries it crosses,” said Mandoske. “When I think of the key challenges of adaptation, I really think it’s just people working together, working through historic distrust and historic conflict.”

Ultimately, managed retreat is just one piece of the overall strategy to adapt to the impacts of climate change, and no one will be forced to pick up and move in the near term. The choice, at least in the Bay Area, will always be voluntary, said Pinter.

“California is different. It’s high-value infrastructure. I see a strong NIMBY element in how people have responded to these proposals,” said Pinter. “This is going to be a case of incremental retreat.”

Still, however incremental, regional planners agree time is of the essence to start planning for this wetter future, no matter how uncertain — or divisive.

“Adaptation is not just we do it and we’re done,” said Mandoske. “We can make decisions today that build resilience and give us options for how we might try to solve these challenges in the future.”

jwolfrom@sfexaminer.com

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