Chapter 1. Population & Land Use

Watershed Land Area Classified as "Forested" Continued to Decline

Between 2001 and 2024 Forest Loss was Estimated at Over 50 Square Miles

At a Glance

Loss of forest lands puts wildlife populations at risk, reduces recreation opportunities, and threatens our waters. Healthy streams, rivers and lakes depend on healthy forests.

Single family building permit applications increased through the COVID-19 years and beyond, indicating a hot housing market.

How we plan and build to accommodate growing populations in the region will determine the health of urban and suburban streams.

Since the 2021 Report

Watershed land area classified as “forested” continued to decline, with a net loss in forest cover between 2001 and 2024 estimated at over 50 square miles. Watershed land area classified as “developed” continues to increase, but the growth in development does not explain the extent of decline in forested areas.  Automation and other recent methodological changes to mapping land use may account for some changes in land cover classification.

Maine is the second fastest growing state in New England and ranked 25th in the country for population growth on a percentage basis. In 2025 a record high population was reached, estimated to total 1,414,874. Broad social and economic trends, including population growth, contribute to changing patterns in where people work and live in the Casco Bay region and, in turn, the intensity of human impacts.

Many environmental stressors affecting the Bay stem from changes in land use in the watershed, particularly loss of forests and the conversion of undeveloped areas to roads, buildings, parking lots and driveways. Suburbanization, or increased development on outskirts of urban centers, of the region contributes to degraded aquatic ecosystems, fragmentation of large undeveloped areas, loss of access to open space, and declines in fish and wildlife habitat.

 

Building Permits Surge in Number

Building permits have shown a tendency to cycle through periods of boom and bust, with a boom in single-family homes permitted in the mid-2000’s followed by a lull in 2010 at the tail end of the financial crisis.

More recently, building permits have surged again, particularly in the years following the COVID-19 pandemic, when opportunities for remote work drove housing purchases from new Maine residents. In recent years, applicants have sought to build proportionately more multi-family residences than in years past.

Suburban development adjacent to the Presumpscot River in Falmouth, Maine. (Image: Jerry Monkman)
Suburban development adjacent to the Presumpscot River in Falmouth, Maine. (Image: Jerry Monkman)

Open Space Planning Around the Bay

Throughout the region, towns including Scarborough, Casco, and Harpswell have embraced open space planning.

Open space planning is a process that seeks to identify priority lands to protect by making intentional choices about the future of communities and balancing growth with preservation of natural areas, rural character, and human uses and activities.

Affordable Housing Remains Key Issue

Above: New building contruction on Commercial Street in Portland, Maine. (Image: Jerry Monkman)

Access to affordable housing remains a critical issue in the Greater Portland Area, putting additional pressure to build housing where land is less expensive and contributing to suburbanization, which can threaten water quality and loss of natural areas for wildlife and recreation.

Looking Ahead to 2030

In the 2023 State of Maine Housing Production Needs Study, HR&A Advisors reported that Maine needs 84,000 housing units by the end of the decade to keep up with population growth.

Development for residential purposes will continue, especially in Southern Maine and the Casco Bay watershed. How we plan and build the housing our communities will need will strongly influence water quality, especially in suburban waters.

*Frye Island has a 20.4% growth rate

An aerial view of US 302 (Forest Ave.), Allen Ave., and Stevens Ave. in Portland, Maine.
An aerial view of US 302 (Forest Ave.), Allen Ave., and Stevens Ave. in Portland, Maine. (Image: Jerry Monkman)