In Falmouth, Dennis, Harwich, and Wareham, thousands more homes than previously thought could be at risk of flooding by mid-century, according to a new online tool that helps people examine flood risks in their communities.
The tool, called Flood Factor, was created by the First Street Foundation, a group of over 70 academics and experts who compiled the data and created the website. The group takes into account a future with stronger storms, higher seas, and more frequent rain. These are just some of the consequences of climate change that are left out of flood assessments by the Federal Emergency Management Agency (FEMA).
“What used to be a 1-in-100-year event, now becomes a 1-in-50, 1-in-20, 1-in-10, once-a-year event," said Christopher Piecuch, an oceanographer at the Woods Hole Oceanographic Institution. "So increases like this … in terms of the number of properties at risk over the next 30 years, it’s not unreasonable.”
Worth noting, he said, is that for the year 2020, Flood Factor finds far fewer homes on Cape Cod are at risk of flooding than FEMA suspects. But when climate change impacts are factored in, a completely new picture emerges.
“Just to give you a sense here: Flood Factor suggests that about 10 percent of properties in Dennis Port right now are at risk from flooding," Piecuch said. "When you look out to 2050, Flood Factor suggests that this is going to increase fourfold to almost 40 percent of properties in Dennis Port,” he said.
FEMA's projections assume far fewer homes are at risk in the year 2050.
Now, Piecuch said, Cape Cod, in particular, needs to start getting prepared.
“As you move into the future and as seas rise, you find out that the Cape is actually— of all of Massachusetts— one of the communities that’s going to experience one of the greatest increases in risk, according to this estimate.”
Piecuch said he hopes people can use these new flood maps and assessment tools to make informed decisions about everything from home buying to town planning.