Sea Level Rise and Potential Impacts by the Year 2100: A Vulnerability Assessment for Saco Bay Communities of Biddeford, Saco, Old Orchard Beach and Scarborough - Maine
Saco Bay is home to Maine’s longest stretch of contiguous sandy beaches, its largest expanse of coastal wetlands, and includes the coastal communities of Scarborough, Old Orchard Beach, Saco, and Biddeford. From the Saco Bay Sea Level Adaptation Working Group (SLAWG), this report provides the results and analysis of projected sea level rise inundation scenarios and land and real estate economic impacts for the Bay. This project was developed with the assistance of the Maine Department of Conservation, Maine Geological Survey (MGS) and the Southern Maine Regional Planning Commission.
The report provides results from an analysis of potential inundation impacts on real estate values in Saco Bay. In order to help determine vulnerable areas within the Saco Bay communities, MGS created a series of images depicting potential inundation scenarios. The inundation scenarios described were used to create a basis for identifying potential, at-risk residential and commercial infrastructure within the partner communities. A summary of potential static inundation impacts by community is provided.
For this assessment, SLAWG documented the potential impacts to structures along the open ocean - and the simulations of potential sea level rise impacts are shown in the report. In an attempt to preliminarily identify such areas, areas along the open coast of the Saco Bay shoreline that may potentially be impacted by dynamic erosion processes within 100 years after 2 feet of sea level rise were analyzed. This area is defined pursuant to the Erosion Hazard Area (EHA) from the Coastal Sand Dune Rules (Chapter 355 NRPA). The potential economic impact of an assumption that all building structures within the EHA are lost is summarized in Table 4. In total, nearly 550 building footprints with a combined assessed value (structure and associated land) of over $461 million are located within the EHA and are likely subject to potential erosion and ocean inundation within the next 100 years.
Based on this preliminary analysis and its assumptions, if both potential impacts along the open coast and static flooding impacts are combined, over $860 Million of building footprints and associated land is potentially at risk in a Highest Annual Tide plus 2 feet of sea level rise scenario for Saco Bay. Should a storm with a water elevation equivalent to the 1978 storm plus 2 feet of sea level rise occur, over $1.4 Billion of structures and associated land value is at potential risk to be impacted in the future.
In early 2009, the Town and City Managers of Saco, Scarborough, Old Orchard Beach, and Biddeford, discussed the idea of the creation of a Saco Bay Sea Level Adaptation Working Group (SLAWG) to develop and implement regional climate change adaptation strategies to respond to rising sea levels and become more resilient to coastal storms in the Saco Bay region. A Regional Challenge Grant from the Maine State Planning Office was applied for and granted to the Southern Maine Regional Planning Commission (SMRPC), for the period July 1, 2009 to June 30, 2010, to fund the initiative. The grant period for the project was extended for an additional six months, until December 31, 2010. The Maine Geological Survey (MGS) provided extensive scientific and technical assistance to the new committee during this period, under separate, parallel funding from the SPO-Maine Coastal Program.
Publication Date: December 31, 2010
- Saco Bay Sea Level Adaptation Working Group (SLAWG)
- Maine State Planning Office