A new report finds that towns on the South Coast and part of the Cape will be severely impacted by flooding during regular high tides within the next 3 decades.
The Trustees of Reservations looked at coastal communities surrounding Buzzards Bay and Narragansett Bay. That includes 14 communities from Falmouth and Bourne to New Bedford and Fall River.
With a projection of 2.5 feet of sea-level rise by 2050, the Trustees predicts that 25 miles of roads and 1,400 buildings across those 14 cities and towns would be flooded during the regular high-tide. Those are low lying roads and buildings that haven't adapted to meet those projections.
Trustees director of coast and natural resources Cynthia Dittbrenner says the study is designed to help plan for the impacts of sea-level rise, but it's also a call to action.
“There are areas we may want to adapt — raise roads, raise buildings — that are critical infrastructure. And there are other areas that we need to critically think about retreating from,” Dittbrenner said.
One major concern for planners will be the hurricane barrier in New Bedford Harbor. The barrier is closed during storm surge events or when tides are particularly high, to protect New Bedford and Fairhaven.
But Dittbrenner says the barrier would have to close during every high tide by 2050 because of sea-level rise.
“That’s clearly not sustainable for a working port," she says. "So what would need to happen, they’d have to close it at a higher water level. Which would mean that waterfronts of New Bedford and Fairhaven would experience higher water levels during floods.”
One way to prevent flooding is to build up natural areas like dunes, beaches and salt marshes that provide a buffer against wave energy from storms and flooding.
But the study also finds that more than 20 percent of salt marsh in the area could be destroyed by sea-level rise. That's with ocean levels rising and flooding salt marshes. Salt marsh can't migrate as they would because of surrounding developments. About 70 percent of the salt marsh in Wareham alone would be destroyed with 2-and-a-half feet of sea level rise.
The Trustees are pushing state lawmakers to approve a bill that would allow residents in areas prone to flooding to sell their properties for the purpose of conservation.
Dittbrenner says 2.5 feet of sea level rise is on the higher end of projections. She said that data was used from Massachusetts and Federal Emergency Management Agency, or FEMA.
The full study is available here: https://www.onthecoast.thetrustees.org/360-virtual-tours
