The Belle Isle Marsh is the largest and one of the last remaining salt marshes in Boston. In addition to being a valuable ecological resource for wildlife and climate resilience, it is an important regional recreation space for East Boston, Revere, Winthrop, and other surrounding communities. The Belle Isle Marsh’s long-term health is influenced by human impacts, both historical and present-day, and by the anticipated effects of climate change. The marsh is existentially threatened by rising sea levels, increasingly intense coastal storms, and dense development along its inland borders. Without active intervention, Belle Isle Marsh will become open water in the coming decades, eliminating its coastal flood protection services, carbon storage, and its role as habitat for over 250 bird species (seven of which are listed as threatened or endangered). Addressing the current and future resilience challenges in the Belle Isle Marsh and the surrounding communities is essential to ensure the healthy function of the marsh as a habitat for plants and animals and as a place for community recreation.

Much of Boston and Revere was built on a salt marsh and the low-lying land is vulnerable to flooding along the entire coastline. Three flood pathways originating from within the Belle Isle Marsh present a risk to East Boston and Revere today, and this risk will increase substantially over time. By the 2030s, with 9 inches of sea-level rise, coastal flooding puts Bennington Street, the MBTA Blue Line Suffolk Downs Station and train tracks, Fredericks Park, and residences along Belle Isle Avenue and Montfern Avenue at greater risk of regular flooding even during typical storms. In the longer term, with sea-level rise projected to occur between 2030 and 2070, flood pathways originating from the Belle Isle Marsh contribute to widespread flooding in East Boston and Revere.

The Study of Belle Isle Marsh is a multi-year Municipal Vulnerability Preparedness grant funded study awarded to the Town of Winthrop with facilitation by the Mystic River Watershed Association and Woods Hole Group. Participants in a regional Stakeholder Collaborative have been meeting monthly since 2021 to assess the current and future impacts of flooding and coastal storms on the Belle Isle Marsh and evaluate potential flood risk reduction strategies and marsh restoration efforts. In addition to the City of Boston, City of Revere, and Town of Winthrop, the participants include representatives from the Department of Conservation and Recreation (DCR), Massachusetts Department of Transportation (MassDOT), MBTA, The Nature Conservancy, Friends of the Belle Isle Marsh (FBIM), and HYM Investments (the owner and developers of Suffolk Downs). 

The Study of Belle Isle Marsh has identified preliminary nature-based and hybrid solutions to prevent damage to the neighboring communities and MBTA Blue Line, promote public safety, and enhance and extend the habitat value of Belle Isle Marsh based on the Massachusetts Coast Flood Risk Model (MC-FRM) projections for 2070. Since the Study of Belle Isle Marsh began in 2021, the Stakeholders identified 12 project locations along the perimeter of Belle Isle Marsh that should be explored further to address climate vulnerabilities and ecological restoration within the marsh. The Stakeholders collaboratively developed prioritization criteria for these sites and selected this location (as well as a location at Morton Street in Winthrop) as a top priority. The Belle Isle Marsh Climate Vulnerability Assessment (2023) summarizes the study and the recommended next steps.

The City of Boston’s Climate Ready Boston initiative completed the Coastal Resilience Solutions for East Boston (Phase II) plan in 2022 (the “Phase II Plan''), which identified the Bennington Street and Fredericks Park area as a near-term priority for coastal resilience due to the extreme flood risk to the East Boston neighborhood and City of Revere. The Phase II Plan was underway at the same time as the Study of Belle Isle Marsh and the two efforts were developed in coordination with each other.

The project will build upon the Study of Belle Isle Marsh, Climate Ready Boston’s findings, and the 2023 Feasibility Report for the project area. The next phase of work will involve advancing the design of flood risk reduction strategies on Bennington Street in Boston and Fredericks Park, Belle Isle Avenue, and Montfern Avenue in Revere. The project would reduce the risk of coastal flooding that enters Boston and Revere via three flood pathways originating in the Belle Isle Marsh under current conditions by elevating the coastal edge of the project area to address a 1% annual chance storm sea-level rise projected around 2070. The project's design that must meet the flood risk reduction objectives while providing a co-benefits, including stormwater management, urban heat island reduction, and improved recreation.

The key goals of this project include:

• Advance the preferred design that will protect East Boston and Revere from the near- and long-term impacts of coastal flooding from sea-level rise and storms; 
• Redesign Fredericks Park to improve coastal resilience, stormwater management, recreation, and ecological habitat; 
• Ensure that all design alternatives support co-benefits along Bennington Street; and
• Support the health and longevity of Belle Isle Marsh.

This project builds off of several years of community engagement by the City of Boston (through Climate Ready Boston's Coastal Resilience Solutions for East Boston (Phase II) planning effort between 2020-2022), the City of Revere (through the MVP-funded Community Resilience Building effort from 2019), the Study of Belle Isle Marsh (between 2021-2023), and the first phase of work for the project (between September 2023 - June 2024). These three efforts have involved many meetings, workshops, surveys, working groups, and outreach to involve the East Boston, Revere, and Winthrop communities in developing coastal resilience strategies surrounding Belle Isle Marsh. See the Past Community Engagement section for more information.

Join us at an upcoming event or email Catherine McCandless (catherine.mccandless2@boston.gov) and Elle Baker (ebaker@revere.org) to share feedback, ask questions, or inquire about your participation! 

The Request for Proposals (RFP) was open between October 30 - December 13, 2023 and describes the project scope and goals. Download or read the RFP here to learn more about the project!