How Is Boston Planning for Sea-Level Rise Protection?

Did you know that much of Boston was once underwater and that the city has created approximately 5,250 acres of new land throughout its history, about one-sixth of its current land area? These statistics should give Bostonians pause, particularly as future rising sea levels could threaten the very infrastructure on which the city now rests.

Boston's made land presents ecological and engineering challenges, including contaminated soils, land subsidence, seismic risk, and heightened vulnerability for neighborhoods such as Back Bay, the downtown waterfront, East Boston, Logan Airport, and the Seaport District.

According to a Next City report, sea level rise projections for Boston by the end of the century range from about 2.5 feet to 6.5 feet or more, with higher risk given a near-10-foot tidal range and the combined effects of storms and tides.

Boston's current resilience strategy centers on the Coastal Flood Resilience Overlay District and Climate Ready Boston. Both efforts aim to shield approximately 47 miles of shoreline with protections focused on low-lying areas and recognized flood pathways.

Institutional efforts include the Office for Climate Resilience, the U.S. Army Corps of Engineers' coastal-resilience study that began in 2022, and the Mass Ready Act state bond to fund resilience and flood-control projects.

“Yet for all its planning for climate adaptation along its shoreline, Boston has not yet identified large-scale investments to turn these plans into reality,” wrote Courtney Humphries of Next City. “Most adaptation projects that have been completed along the shoreline have involved parcel-by-parcel protection measures. Stitching together larger flood protection for areas with a mix of public and private landowners will require coordinated planning and marshaling new sources of financial support.”

Indeed, some of the major challenges include governance and financial hurdles stemming from regulatory complexity, public engagement fatigue, and the need to move beyond engineering fixes toward adaptable governance and innovative financing.

“Although managed retreat has been essentially absent from discussions of adaptation in Boston, as the risks and costs of waterfront development grow, the city may face diminishing investment in the waterfront, even if the word 'retreat' is never used,” Humphries concluded.