Falmouth

Community Profile

About Falmouth

Falmouth features a rocky coast, beaches, the Presumpscot river, and Mackworth Island. As the Town begins to face more severe and frequent coastal flooding, the environmental, economic, and community benefits of these sites are at risk. Coastal risks in Falmouth include flooding of low-lying sites, eroding shorelines, and damage of coastal infrastructure from severe storms.

Keep scrolling to learn about Falmouth's infrastructure and ecosystems in the context of future climate risks.

Navigating the Profile

This data profile is divided into 7 sections to present maps and data which help assess Falmouth's coastal vulnerabilities. The first five sections contains resource-specific data. The last two sections combines all of the data to asses the co-occurrence of resources. You can scroll through this report one section at a time or you can click the section heading in the navigation bar on top to jump to a specific section.

  1. Flooding Risk - Visualize how sea level rise and 100-year flood risk could impact the coastline
  2. Coastline Changes - Learn which areas are most at risk to coastal erosion
  3. Habitat and Natural Resources - Discover where marine habitat such as eelgrass and tidal marshes are present in town
  4. Infrastructure - Explore which roads, buildings, culverts, and coastal infrastructure are most at risk to flooding
  5. Social Vulnerabilities - Discover how social vulnerability varies across town.
  6. Vulnerability Hot Spots - This section combines the data presented in the earlier sections to assess key vulnerable areas for the town to focus.
  7. Explore the Data - an interactive map containing all data presented in this profile

Using the maps

  • The maps below are interactive; users may zoom in or out and select various features.
  • It may be helpful to give computers some time to load each section.
  • Map legends can be expanded by clicking the icon in the lower left of each map window. 
  • The maps can be made full screen by clicking the arrow icons in the top right corner.
  • Data sources are listed and linked at the bottom of this page.

Flood Risk

Takeaway

Falmouth's coastal bluffs helps to protect the town from flooding and sea level rise. However, several areas, particularly along river outlets are more vulnerable.

Falmouth's coastal frontage exposes it somewhat to rising sea levels and storm surge.

Contour lines can help visualize this steep topography. Here, orange lines represent elevations between 0 and 10-feet above sea level (in 2-foot increments).

The current highest astronomical tide (HAT) is displayed in red. HAT is the highest tide that can occur under average weather conditions, and is about 1.9 feet higher than Mean High Water in Casco Bay (the average height of daily high water). It provides a useful baseline for assessing potential sea level rise.

The State of Maine estimated sea level rise scenarios on top of the HAT. The State asks communities to commit to managing 1.5 ft of sea level rise by 2050 and 4.0 ft by 2100 (relative to a year-2000 baseline).

The map at right shows the area expected to be inundated with 1.5 feet of sea level rise. Note that extreme storm surges (the rise in water level from storm winds piling water up at the coast) can reach around 3-4 feet above sea level.

The amount that sea level will rise depends in part on what we do to curb greenhouse gas emissions, communities should account for multiple future sea level rise scenarios. In this visualization, 3.9 feet of sea level rise encroaches farther inland. The State asks that communities be prepared to manage for this level of water, especially for high priority infrastructure, ecosystems and when people are at risk.

The Federal Emergency Management Agency (FEMA) maps the area likely to be flooded by severe storms that have a 1% chance of occurring within a given year, under current conditions. Over thirty years, there is a 26% chance that a storm of this severity will occur at least once, so it's important to plan for.

Together, these predictions (FEMA "100-year" flood risk and HAT + 3.9 feet of sea level rise) provide a look into how flooding could impact our coastlines, habitat, infrastructure, and people within this century. FEMA does not factor climate projections into their flooding maps, so combining with sea level rise maps show a more complete picture of impacts.

The Gulf of Maine Research Institute’s (GMRI) Coastal Flooding Community Science project allows community members to interact with and understand local flood risk. This map includes Falmouth's monitoring sites. Residents can capture photos of the site in varying conditions, and upload it to GMRI’s Ecosystem Investigation Network, contributing to local data and building community knowledge of coastal climate risks and opportunity for resilience.

Continue below to learn about other potential impacts of sea level rise and climate change.

Coastline Changes

Takeaway

Most of Falmouth's coastline is unstable coastal bluffs at risk of erosion. There is also a small section of sand dunes that should be monitored and protected.

The Maine Geological Survey assesses coastlines for erosion and beach changes. In the map below, orange indicates areas with coastal bluffs are observed to be potentially unstable, while red indicates coastal bluffs deemed highly unstable, and yellow lines indicate coastal edges that appear to be vulnerable to landslide hazards.

Sand dunes are an important coastal defense against flooding, but are subject to erosion. Here, an area of sand dune is delineated by the shaded polygon, while water overtopping potential is indicated by the colored circles. Beach and dune health should be monitored so that relevant restoration efforts can occur.

Habitat and Natural Resources

Takeaway

Falmouth has significant marine and coastal habitat home to critical species. Fortunately, many of these areas are already conserved. However, development pressure, especially along tidal marshes could impact these resources and risk flooding to surrounding areas.

Tidal Marshes

Coastal marshes protect our coastal infrastructure, homes and ecosystems from flooding. They also provide essential habitat. Sea level rise and erosion will impact marshes, if marshland has no areas to migrate upland, they will become inundated and disappear. Development (current or future) limits where potential future marsh habitat can exist. In the map below, slide the divider left to see how estimated tidal marsh areas expand inland with 3.3 feet of sea level rise assumed.

Eelgrass

An ongoing habitat change is reduction in marine eelgrass within Casco Bay. Eelgrass is ecologically significant, and its presence is important for many other sea-dwelling organisms. With warming in Casco Bay, eelgrass beds are shrinking. Here, the slider compares eelgrass bed presence and coverage percentage in 2013 (left of the slider) and 2022 (right of the slider).

Natural Resources

Wetlands and wildlife habitat are critical to a healthy ecosystem and can provide a buffer against flooding. Knowing where these resources occur in town, and protecting both the habitat and surrounding areas will ensure these resources continue to exist and provide resilience to the changing climate.

Wetlands (tidal and non-tidal) serve as crucial habitat for a variety of species and provide significant natural resilience to flooding. 

Some organisms, like molluscan shellfish (habitat of which is mapped at right), are important culturally as well as economically and environmentally. 

Various bird species require appropriate tidal habitats; rising sea levels and increased flooding may eliminate some of this habitat. Highlighted here are tidal wading bird habitats and seabird nesting islands. 

While all habitat is valuable, Falmouth has areas, shown in green, home to particularly vulnerable wildlife. Relevant species include roseate tern and least bitern. 

Because habitat can be disrupted by inland or coastal flooding, it may be helpful to provide buffers around habitat areas. This provides the opportunity for plants and animals to shift into new locations without the threat of encroaching development. 

Fortunately, a number of spaces within the Town's border are already protected for conservation or open space, mapped at right. 

However, there are many other areas across the Town that are currently undeveloped, but unprotected. Conservation and regulation of these areas can assist with habitat retention, as well as flood mitigation by allowing water to infiltrate below ground. 

Infrastructure

Takeaway

Coastal structures, including the Town Landing, are at risk of due to sea level rise and flooding. In addition, flooding of bridges could limit access, especially to Mackworth Island.

Important infrastructure can also be threatened by flooding, resulting in safety hazards and costly repairs. This map displays a selection of such infrastructure, such as docks, boat launches, public access to waterbodies, bridges, and dams. The resilience of this infrastructure should be examined and, where necessary, improved. 

The Nature Conservancy developed an analysis of culverts at risk of overtopping in a flood. Several culverts in Falmouth are assessed at high or medium risk for overtopping. These culverts should be examined and potentially improved. 

Also at risk are elements of the area's transportation network. Shown here are roads and transportation routes, as well as the previously flood hazard and sea level rise layers. 

Residents and emergency services should be aware of areas and road segments where access might become limited with flooding; this could result in safety hazards as well as travel impediments to private and public transit. These road segments are highlighted in yellow. 

Several buildings in Falmouth intersect with these estimated flooding areas as well. These are highlighted in red on the visual at right. These should also be assessed for safety, stability, and resilience in the event of flooding, storm surge, or sea level rise. 

Other neighborhoods farther inland could be cut off from normal access routes because of flooding and the limited road network.

Social Vulnerabilities

Overall, Falmouth has a lower social vulnerability, meaning the residents are relatively resilient to climate. However, there are pockets of higher social vulnerability and individuals may experience the impacts differently.

Various populations may be particularly vulnerable to climate change.   The Maine Social Vulnerability Index   uses a variety of socioeconomic, demographic, and geographic data indicators to identify areas where people may be more or less vulnerable to flooding. (More vulnerable census tracts are represented in darker shades). 

Many livelihoods depend on a clean, sustainable aquaculture industry. Several aquaculture sites and leases are present along the Falmouth coast that could be affected by negative impacts of climate change.

Vulnerability Hot Spots

Takeaway

The town will need to protect the tidal marshes along at the Presumpscot River outlet to maintain critical habitat and flood protection for surrounding development. The Town will also need to monitor and bolster shoreline defenses along its bridges and at Town Landing.

There are a few key areas of potential marsh migration along the outlet of the Presumpscot that are currently unprotected. Some of this marsh abuts neighborhoods and essential infrastructure like Falmouth's Waste Water Department buildings. As sea levels rise and this natural flood protection is lost to inundation this infrastructure and residential areas may need interventions to protect against flooding.

In Falmouth there are significant areas of least bittern habitat that is not conserved and could be threatened by future development.

Coastal defenses and infrastructure along Andrews Avenue to Mackworth Island and the Martins Point Bride on Route 1 to Portland are at risk of overtopping. This infrastructure is also at risk of future flooding and could sustain impacts that cut off travel.

The potential for flooding, and any impact on emergency services and travel, should also be considered at at the the I-295 bridge over the Presumpscot River.

Falmouth has three at risk dams that should be assessed for longevity, resilience, or maintenance if necessary. Potentially undersized culverts identified by the Nature Conservancy should also be assessed, and improved if necessary.

The Town Landing currently floods in high water and has sustained impacts from storms. The Town is studying opportunities for improving vulnerability. The riprap and coastal defenses here are shown to be at risk of overtopping.

Flooding of Foreside Road could limit access to and egress from the surrounding coastal neighborhood. There are also at risk coastal bluffs along the coast here and some town owned infrastructure at risk.

Explore the Data

Each of these data points and vulnerabilities can inform and build off one another to help develop resilience priorities. In the map application below, everything displayed thus far can be turned on or off to identify relationships between flood risk, shoreline, habitat, infrastructure, and social vulnerability.


Data Links and Sources

Flood Risk

Coastline Changes

Habitat

Infrastructure

Social Vulnerability