A granite seawall along a Boston Harbor waterfront under storm clouds, illustrating the Boston coastal flood protection plan.

Boston Coastal Flood Protection Plan Wins Council Backing

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The Boston City Council has adopted a resolution supporting the city’s push for federal authorization of the U.S. Army Corps of Engineers’ coastal flood protection plan for Boston Harbor, according to a council news post published Oct. 13, 2026. The plan, known as the Boston Harbor Coastal Storm Risk Management Comprehensive System Plan, carries an estimated cost of $9 billion to $10.5 billion.

The resolution does not approve spending or construction. It records the council’s support for the city’s application and lists priorities the council wants the Army Corps, the city and state and federal partners to follow as the plan moves forward.

Boston Coastal Flood Protection by the Numbers

  • Estimated cost: about $9 billion to $10.5 billion for the full system, according to the Army Corps’ executive summary.
  • Cost share: implementation is generally eligible for a 65 percent federal and 35 percent non-federal split, the council’s post says.
  • Risk without action: the Army Corps estimates coastal flooding could affect more than 20,000 structures and cause more than $54 billion in cumulative damage.
  • Study area: 47 miles of Boston coastline across Charlestown, East Boston, Downtown and the North End, South Boston and Dorchester.
  • Next milestones: a USACE decision point in fall 2026, a final feasibility report in fall 2027 and a signed Chief’s Report in spring 2028, according to the city.

What the Council Resolution Asks For

According to the council, the resolution calls for building and sequencing the work to put life safety, emergency access and evacuation routes, critical infrastructure, environmental justice communities and socially vulnerable residents first. It also asks that protection in one area not shift flood risk to another.

The resolution names East Boston as a priority because of flood exposure affecting homes, schools, small businesses, the MBTA Blue Line, the harbor tunnels, evacuation routes, infrastructure near Logan Airport and the Chelsea Creek industrial and fuel facilities. It supports designating an early actionable element in East Boston and calls for a waterside alignment along Border Street, consistent with the city’s Resilient Border Street Waterfront Project.

For Charlestown, the resolution points to flooding that can come from several directions at the Navy Yard, the Little Mystic Channel and the Mystic River, and calls for a continuous line of protection that protects historic resources and keeps the Harborwalk connected. It also asks that the full “DT-3” downtown alignment be advanced, and that the work include stormwater and drainage systems, planning for compound flooding, reliability analysis of deployable gates and designs that can adapt to future sea-level rise. The council urged partners to publish transparent timelines and funding responsibilities and to keep engaging the community.

What the Army Corps Draft Plan Proposes

The Army Corps released its draft feasibility report and environmental assessment on July 24, 2026, and the public comment period has since closed, according to the city’s partnership page. The executive summary describes a “no action” option (Action Plan 1), the full comprehensive system (Action Plan 2) and a first early element (Action Plan 3).

In the draft, that early actionable element is in Dorchester: an upland wall behind Day Boulevard that transitions to a levee through Moakley Park. The council’s resolution asks for an early element in East Boston. The Army Corps has not yet selected a final plan. The executive summary also says the full system may not fit within the current study’s time and budget for the detailed designs Congress would need, and that it could still be built through later federal actions.

The study itself is cost-shared 50/50 between the city and the federal government, and the city says it has committed to the work in its capital budget. For more on city finances, see our coverage of Boston’s FY27 budget.

Why It Matters for Boston Neighborhoods

According to the city, more than 40 percent of Boston residents live in areas at risk of coastal flooding, and between 1991 and 2026 Boston saw 24 severe weather events that led to federal or state disaster declarations, 14 of which involved flooding. The Army Corps summary says relative sea level in Boston could rise as much as four feet by 2090. Boston’s waterfront was under coastal flood watches during the late-September nor’easter.

The city says that every dollar spent on protection could prevent more than $4 in losses. Federal construction money would depend on congressional authorization after the study is complete.

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