Some of Maine’s priciest and most sought-after homes are along the coast, but that could change as sea levels rise in the coming decades.
While climate change and subsequent sea level rise has happened slowly — with only eight to nine inches of elevation gain since 1880 — the National Oceanic and Atmospheric Administration warned that coastal flooding is expected to accelerate in the coming decades.
NOAA projects seas will climb another foot along the U.S. coast by 2050.
This will mean some coastal communities could see more frequent and severe flooding during high tides and storms, which pose a risk to homes and properties that house essential services in those regions.
Climate experts recommend buyers consider these five things when looking to purchase a home in Maine, as they could make an area especially susceptible to storm surge.
Small islands or peninsulas with limited freshwater
Sea level rise could make freshwater aquifers brackish, meaning a community’s drinking water becomes salty and unfit for consumption, said Parker Gassett, assistant director of the Maine Climate Science Information Exchange at the University of Maine. This would be especially problematic in island communities with limited freshwater resources.
That includes North Haven or Stonington, two island communities that have publicly detailed how freshwater resources are limited.
Last month, the Stonington Water Company issued a mandatory water conservation notice to residents that lasts until the end of August warning of waning resources. If that continues, the town will need to transport freshwater into the community, the notice said, which would be costly for residents.
Communities with single access roads or causeways
Having more than one access road is crucial for public safety, Gassett said. If the single access point becomes impassable due to flooding, residents have no way to leave and emergency services can’t reach residents.
“In a storm event, emergency responders need to be able to reach the elderly, people with disabilities or those with medical needs,” Gassett said.
Communities built on narrow coastal peninsulas, such as Harpswell, are an example of this, as a main road connects both Orr’s and Bailey islands to the mainland.
Even if a community plans to create another access point to mitigate that risk, the high cost of that work will fall on residents if the community doesn’t receive a grant or other funding, Gassett said.
Areas at low elevation or that are built on filled land
As rising sea levels make coastal flooding more common, especially during storms and exceptionally high tides, storm surge can creep farther inland in communities with low-lying areas, causing widespread damage.
Portland’s Old Port — especially Commercial Street and the adjoining piers that jut into the harbor — is an example, as much of that area is on filled land. That portion of Maine’s largest city has already seen increased flooding during storms and high tides in recent years.
Filled land describes tidal areas where humans have added materials, such as dirt and gravel, to raise land heights above sea level. While filled land can meet an immediate need, it’s also at a greater risk of instability and erosion over time compared to bedrock as coastal flooding becomes more common, which puts the infrastructure built on it at risk, Gassett said.
Dave Reidmiller, chief impact officer for the Gulf of Maine Research Institute, said prospective buyers can use past storm and flooding events when considering how resilient an area will be to similar events in the future.
For example, Reidmiller said the back-to-back storms in January 2024 brought “unprecedented water levels as a result of strong storms hitting at particularly high tides” that caused severe damage to low-lying coastal neighborhoods in southern Maine, including Pine Point in Scarborough and Camp Ellis in Saco.
While a resident’s home may sit on higher elevation, taxpayers in coastal areas inevitably pay more when their communities have to build or repair infrastructure designed to mitigate the effects of climate change, such as sea walls or drainage, Gassett said.
Spots where the most critical infrastructure is in a flood zone
While a person’s house might sit outside of flood zones, essential services like wastewater treatment plants, hospitals or public safety departments being shut down by flooding would still directly harm residents, Reidmiller said.
When considering whether to move to an area, Reidmiller recommended buyers consider whether a community is exploring and pursuing measures to adapt to climate change — especially if critical infrastructure is at risk of flooding.
In South Portland, a school, fire station and police station are close to the coast, putting them at risk of sea level rise, according to the Natural Resources Council of Maine. It’s a similar story in Kennebunkport, where a public library, fire station and school all sit in coastal flood risk areas.
Taxpayers would also likely foot the bill for repairing or rebuilding essential buildings like schools or wastewater treatment plants, Gassett said.
“Your house might be fine, but rebuilding the school, fire station or wastewater treatment plant will still cost a lot of money,” Gassett said. “Sea level rise doesn’t just change the shoreline, it changes municipal budgets.”
Homes on flood maps or with risk disclosures
A new law passed in 2024 requires sellers to disclose whether their properties are in
a Special Flood Hazard Area, which the Federal Emergency Management Agency maps.
This law helps buyers feel more confident about whether their new home is at risk of flood damage, as not everyone would know to check FEMA flood maps, said Judith East, director of the Maine Bureau of Resource Information and Land Use Planning under the Department of Agriculture, Conservation and Forestry.
Being listed in a flood zone could also drive up insurance costs or harm resale values.
These disclosures must also say whether a property was damaged by flood waters or received disaster-related aid while the seller owned the home.
“With climate change, a lot of flooding is happening outside flood hazard areas noted by FEMA,” East said.
In addition to required flood risk disclosures, buyers can check state climate change mapping tools and NOAA’s online sea level rise tracker, which shows what portions of Maine would be underwater with various degrees of sea level rise.
Buyers should also consider whether the community they’d like to move to has a climate action plan, East recommended, as that could indicate whether local leaders are preparing for the coming effects of climate change.