HARPSWELL — Residents packed the town office meeting hall on Tuesday, anxious for a glimpse of what sea level rise might hold for the town.
Murmurs of concern came from the crowd of about 50, who watched parts of Harpswell’s shoreline and critical infrastructure disappear beneath rising water, displayed on a digital map projected onto the wall.
While the town’s high shoreline mitigates the impact of the highest estimated rise – 3 feet – the projection pointed out several risks: swamped residences, engorged marshes, and flooded causeways linking the town’s archipelago to the mainland.
The workshop, held by the town’s Conservation Commission and Planning Board, was the first step to sketching out how Harpswell will meet the challenges presented by rising seas.
The town joins more than 30 other coastal communities that are wrestling with scenarios that put some of their towns under water, Peter Slovinsky, a geologist with the Maine Geological Survey, told the crowd.
For years, the MGS has been mapping the state’s coast with airborne radar and using advanced modeling to create a geographic template with estimated future water levels.
The department is offering its data and assistance to towns and cities as they begin to think about the issue.
“We’re trying to create data that municipalities can use in a plethora of different ways,” Slovinsky said.
Using data gathered from the Portland tide gauge, scientists predict that warming oceans and melting icecaps will push local sea levels up a foot by 2050 and as much as 3 feet by 2100, Slovinsky said.
Rising sea levels may also increase the chance that coastal communities will witness higher-than-normal storm surges in the same areas at risk for sea-level rise. Flooding from hurricanes may also be more serious, Slovinsky added.
Scott Hastings, of the Midcoast Council of Governments, noted Harpswell may get off lightly under most of the MGS scenarios.
MCOG is working with Harpswell and other southern mid-coast communities to work on resilience strategies, he said. It is providing its sea level maps free of charge through its website.
“Like most of Maine’s coast, Harpswell is in pretty good shape,” thanks to elevated, rocky shorelines, Hastings said.
The town is certainly better prepared to weather rising sea levels than his own home town of Scarborough, where hundreds of acres could be at risk, Slovinsky noted.
Still, rising seas could leave the approaches to bridges and critical roads under water, cutting off areas of town, including a section of Route 123 on the border with Brunswick.
Even though the scenarios presented are worrying, they provide an important baseline to start considering how Harpswell will plan for the future, resident Paul Ciesielski said.
“It’s useful, not just from a theoretical point of view, but to see where the choke points can be flooded,” Ciesielski said after the meeting. “It presents us things that we can set onto a schedule for future mitigation.”
Peter Slovinsky, a geologist with the Maine Geological Survey, points out areas in Harpswell that might be at risk of flooding in the event of a serious coastal storm.