Boston Coastal Flood Plan Seeks Comment on Preliminary $9B-$10.5B System

Boston residents can now review and comment on a preliminary coastal flood-protection plan that could guide billions of dollars in infrastructure work over the coming decades.

The City of Boston and the U.S. Army Corps of Engineers released the draft Boston Coastal Storm Risk Management study on July 24, 2026. Public comments are due by 5 p.m. on September 18, 2026.

Where the draft plan would apply

The study considers more than 20 potential infrastructure projects along roughly 16 miles of Boston’s approximately 47-mile shoreline. Its five focus areas are East Boston, Charlestown, Downtown/North End, Dorchester, and South Boston.

The study is intended to address coastal flood pathways that could affect waterfront neighborhoods as well as inland streets, buildings, parks, public-access areas, and important civic and transportation infrastructure. The materials also discuss possible effects around Moakley Park and Boston Harbor access.

What the Army Corps is considering

The draft does not select final construction projects or alignments. Instead, it evaluates a range of possible measures, including floodwalls, levees, floodgates, elevated pathways, building retrofits, permitting and zoning tools, evacuation planning, and nature-based features.

Some concepts could change how residents and visitors move along the waterfront or use parks and harbor paths. Other measures could involve adapting individual buildings or changing rules for future development. The final mix would depend on additional engineering, environmental review, community input, and federal decisions.

The preliminary cost is between $9 billion and $10.5 billion

The draft full-system cost varies from approximately $9 billion to $10.5 billion, depending in part on alternatives still under consideration in Downtown and South Boston. That is a preliminary planning range, not a final price tag or a direct estimate of what Boston taxpayers would pay.

The study assumes a potential 65% federal and 35% non-federal cost share if a project is eventually authorized. That assumption is not a congressional authorization, appropriation, or adopted local funding commitment. How the non-federal share would be divided among Boston, Massachusetts, public agencies, private owners, or other partners remains unresolved.

What happens next

The study is still moving through the Army Corps’ feasibility process. Project alignments, construction sequencing, funding, local responsibilities, and the timing of any work remain open questions. The city and Army Corps have described a possible Chief’s Report in 2028, but that would not itself guarantee construction funding or completion.

Residents can review the draft materials, neighborhood summaries, maps, and public-engagement information through the city’s coastal resilience program. Comments may be submitted through the online form, by email to boston-csfrm@usace.army.mil, or in writing to Todd Randall, U.S. Army Corps of Engineers, New England District, ATTN: COB CSRM Project Team, 696 Virginia Road, Concord, MA 01742-2751.

For residents, property owners, businesses, and organizations in the five focus areas, the current decision is not whether a particular wall, gate, or pathway will be built. It is an opportunity to weigh in while the federal study is still evaluating alternatives. The next major questions will be which projects remain in the plan, how public access and neighborhood design are handled, and who ultimately pays for the work.

Sources

• City of Boston draft coastal flood plan announcement
• U.S. Army Corps Boston Coastal Storm Risk Management project page
• WBUR report on Boston waterfront flood defenses