Bay Area towns need to address sea-level rise. Will they?

FOSTER CITY, a community of curving streets and cul-de-sacs, edges up to California’s San Francisco Bay. Built on wetlands that were drained and filled more than a century ago, the city was barely above sea level to begin with. Today, 34,000 people live in Foster City, and all that keeps water from pouring into their streets and neighborhoods is an earthen levee fortified by concrete and riprap. With climate change raising the sea level, this won’t be enough to protect the small city. So, in 2016, officials floated a plan to raise the levee. 

That worried Hank Ackerman, the flood-control program manager for Alameda County, which lies just across the bay from Foster City. Ackerman wrote in a 2017 letter that he was “very concerned” that raising the levee could shift floodwaters to Alameda County much of whose 36 miles of shoreline is densely populated. He cited research showing that raising seawalls in one area can simply transfer the rising waters elsewhere. “To address sea-level rise jurisdiction-by-jurisdiction will result in an acceleration in the adverse impacts to other entities around the Bay,” Ackerman concluded.