Study shows sea level rise threatens critical infrastructure on New Hampshire’s seacoast

A recent study from the Union of Concerned Scientists shows as sea levels rise, pieces of critical infrastructure in New Hampshire could be threatened by flooding from the ocean on a regular basis.

In a medium sea level rise scenario, where the ocean rises about 3.2 feet, a fire station in Hampton would flood about twelve times a year by 2050. An affordable housing unit in Exeter could flood 26 times a year.

As time and sea level rise go on, wastewater treatment plants in Hampton, Portsmouth and Seabrook could expect regular flooding, too.

All told, up to six critical infrastructure assets would be threatened by flooding about twelve times a year by 2100, the study shows.

In a high scenario, with about 6.5 feet of sea level rise, that number jumps to 10, and critical infrastructure is at risk of flooding about 26 times a year.

The study only considered coastal infrastructure that would flood from the ocean itself. Extreme rainfall and river flooding are also increasing threats as the climate continues to change, but those risks aren’t included in this research.

Kristina Dahl, who worked on the project for the Union of Concerned Scientists, said in some ways, New Hampshire is lucky.

The state has less critical infrastructure on the coast than most other places. Nationwide, 1,600 pieces of critical infrastructure on the coasts are expected to flood twice a year or more from sea level rise, according to her research.

Researchers say because it’s a problem that can be anticipated, it’s a problem that can be addressed.

“This is not should not come as a surprise to us in the year 2050 that we have facilities that are at risk,” she said. “Because infrastructure is so long lived, and because the decisions that go into adopting infrastructure are so difficult and require a lot of community engagement, we really need to start now so that we're prepared for 2050 or 2100.”

Dahl says communities could use the data as a starting point for more detailed local risk assessments, which could help begin conversations about how to plan for the future. That could include moving or retrofitting buildings.

The changes needed to protect infrastructure from the rising ocean could be expensive, Dahl said. Fossil fuel companies are one place some communities, including the state of Vermont, are looking for the money to become more resilient to climate change.

“As we think about how we're going to fund this major effort toward climate resilience along our coasts, it's important that we look to the accountability of those companies that have contributed so much to the problem,” she said.

According to scientists, some amount of sea level rise is already locked in, particularly through 2050. But the amount that may threaten infrastructure in the latter part of the century depends on how much the world cuts climate polluting emissions.

This story is a production of the New England News Collaborative. It was originally published by New Hampshire Public Radio.