The Kennebunk Select Board and Kennebunkport Board of Selectmen heard a presentation on floodproofing at a joint meeting last week.

The Southern Maine Planning Development Commission, along with the New England District Corps of Engineers, presented three possible options to prepare buildings in Dock Square and along the coast for future flooding.

Over the last few years, the development commission has been working with the towns on coastal resilience planning projects, and has conducted studies looking at the impacts of sea level rise and coastal flooding in both towns.

The impacts, corps of engineers Coordinator Sheila Warren said, are severe.

Route 9 near Dock Square in Kennebunkport was closed due to flooding in January. Gregory Rec / Portland Press Herald

“Water is here, floods are happening,” Warren said. “It’s not a phenomenon that happens.”

Both towns have seen the impacts of coastal flooding in the last year alone. Multiple winter storm in January rocked the coastline, leaving both towns with severe damage to infrastructure and buildings, including historic buildings.

“Floodproofing of historic structures is a big issue,” Warren said.

This is because of the structures’ locations. Many historic buildings are located in low-lying areas, Warren said, where people originally settled in the town.

Will Wierda, a historic buildings specialist with the corps of engineers, said Dock Square is one of these areas that will be most impacted by coastal flooding.

“All of these sites along the Atlantic Coast and along the Kennebunk River are going to be most impacted by coastal flooding,” Wierda said.

But there are options to create building resilience to flooding, including for historic structures.

One of these options is non-structural flood proofing. This includes smaller interventions that are not levees, dams or sea walls. It also includes wet floodproofing, which allows water to enter a building without causing damage.

Tools like sump pumps, floor and foundation vents, interior flood walls, and storm hatches are often used in wet floodproofing.

Another option is dry floodproofing, which stops water from entering a building in the first place. This typically includes storm doors, storm windows, inflatable barriers, waterproof membranes, raising utilities or raising the building itself, and moving a building to higher ground.

The focus in this case is dry floodproofing, Wierda said.

A payloader clears beach stones from Beach Avenue in Kennebunk following a winter storm. Gregory Rec / Portland Press Herald

“A lot of the recommended measures involve flood hatches and adding flood resistant material to the ground floor, as well as elevating utilities,” he said.

Wierda presented three potential options to the town boards, each with varying costs.

The first option, which Wierda categorizes as only “good,” includes hatches and utility elevation. In a typical Dock Square building, the cost would be just under $300,000.

The second option is the recommended option, and includes hatches and flood proof materials. The cost of this option is just over $450,000.

The third and final option would be to elevate buildings and utility tanks, and would cost over $1.5 million.

“There are a lot of challenges with raising buildings in the Dock Square area, where a lot of buildings share walls or are very close together,” Wierda said.

Board members echoed this concern.

“A lot of Dock Square buildings were built on old piers,” Kennebunk Select Board member William Ward said. “I would think that would be very challenging.”

No decision was made at last week’s meeting, but both boards will continue to work on the issue of floodproofing and coastal resilience over the next few months.