Coastal Resiliency along New Hampshire Seacoast

Portsmouth flooding photo - Tim Hayes

If you have read the news lately you will have seen that sea level rise and coastal resiliency planning are making the front page, especially along the New Hampshire Seacoast. Sea level rise and adaptation in coastal communities was the topic of a five-article series on Seacoast Online this summer written by Deborah McDermott. And for good reason, as sea level rise presents real threats in coastal communities.

Projections based on LIDAR modeling (a laser measuring system) indicate that the Seacoast region will see about 2 feet of sea level rise by 2050 and between 3 and 6 feet by 2100. (NHDES) Add a storm surge on top of that, especially if a storm should happen at high tide or during spring tides (highest tides of the month), and it is

obvious that many coastal communities would be in trouble.

Much is at risk in the Seacoast. In the city of Portsmouth, $32-$600 million in property would be vulnerable to sea level rise and storm surge in the future. In Hampton, Hampton Falls, and Seabrook, a 2012 study estimates the cost is between $1.9 billion and $2.8 billion.

Fortunately, there is NHCAW! The New Hampshire Coastal Adaptation Workgroup (NHCAW) is a collaboration of organizations working to help communities in New Hampshire’s Seacoast area prepare for the effects of extreme weather events and other effects of long term climate change. NHCAW provides communities with education, facilitation and guidance.

And fortunately, many of the Seacoast towns understand the urgency to begin planning for sea level rise now. The City of Portsmouth recently completed a vulnerability assessment that will be used as a guide for the next iteration of its master plan. Peter Britz, the city’s environmental planner and sustainability coordinator, said the price of adapting to sea level rise is four times less than the cost of simply losing vulnerable swaths of the city.

It is a similar story in Hampton and Seabrook. If adaptation measures are taken over the course of the next few decades, the cost benefit ratio ranges from 2:1 to as much as 10:1 compared to taking no action.

New Castle, Rye, and North Hampton are all in the process right now of starting to evaluate their resources and are discussing incorporating sea level rise and storm surge into their planning. Rye is updating its town’s master plan to incorporate language about sea level rise. York, Maine is adding a sea level rise chapter to the town’s comprehensive plan, which will go up for approval in November.

Along the Seacoast, sea level rise and climate change, are no longer “hot topics” within community planning boards. Coastal communities have conceded to the inevitable and are accepting the challenge to make their towns resilient and prepared for the future. We encourage you to follow the NHCAW blog and visit the StormSmart Coasts website for updates on new initiatives and activities in climate preparedness in New Hampshire.