Hampton Voters To Decide On New Building Requirements For Flood-Prone Homes

Mar 11, 2019

"King" high tides, like this nearly 10-foot one seen from above in January, can bring floodwaters into Hampton's marsh-facing neighborhoods.
Credit Annie Ropeik / NHPR file photo, aerial support by Lighthawk

At town meeting in Hampton Tuesday, residents could take another big step in adapting to rising seas.

Voters will decide whether to require pilings under new structures in certain at-risk coastal areas.

Hampton conservation commission chair Jay Diener says the town already has this policy, which stems from federal flood insurance requirements, for a strip of homes that directly face the ocean.

It’s based on federal flood insurance standards for “coastal high hazard” areas, which require all new structures or ones undergoing major renovations to be put up on pilings that allow floodwaters flow underneath.

Hampton adopted the latest federal flood maps, which carry these requirements, in 2015.

This year, they’ll vote on extending those “high hazard” requirements to other zones – covering the entire tidal wetlands conservation district.

The town warrant also includes other proposed zoning changes that would support the pilings policy.

The affected neighborhood typically floods during storms and 10-foot-or-higher high tides – which are happening more and more frequently, according to the National Weather Service.

Diener says the zoning change would cover around 340 homes, but wouldn’t actually affect many directly. He says it aims to protect homeowners who choose to invest in staying in a flood-prone area.

"Also it's in the best interest of the town, especially when you look at what services might be necessary to protect or rescue people,” he says.

The zoning change would require pilings like these, which allow water to flow underneath homes, for new constructions in the flood-prone district.
Credit Courtesy Jay Diener

But it won't solve the issue of road flooding. Diener says that's a bigger problem the town will have to figure out how to tackle in future.

He says the pilings requirement is a manageable first step as the town mulls larger changes to protect against increased flooding.

"This is an adaptation strategy, you know – get your structure out of the way of the water,” he says.

Federal data and many studies, including one from the Union of Concerned Scientists and the real estate website Zillow in 2018, show Hampton faces some of the greatest risk in the region from rising seas.

The 2018 study analyzed federal sea level rise scenarios, including a “moderate” case that assumes carbon emissions begin to decline by mid-century and the ice sheets follow their historic melting trends.

The study says this would lead to about a foot of sea level rise by 2035 and four feet by 2100.

It puts more than 700 homes – valued today at more than $215 million dollars – and 1,100 people in Hampton at such a risk of chronic flooding that the study suggests they would likely have to move.