Climate Ready Boston
Boston's 2016 climate study put 36 inches of sea-level rise as early as the 2070s, and mapped the flooding that follows. The maps are open data, and since 2021 a zoning overlay makes them binding: new buildings in the 2070 flood area must sit above a design flood elevation. A study the city commissioned then talked it out of a harbour barrier.
Live
📅 since 2016
✔ Editor-reviewed
📊 Impact
The 2018 barrier study Boston commissioned priced an inner-harbour barrier at up to $8.7 billion and an outer one at up to $11.8 billion, assumed at least 30 years to build them, and advised against both; the city dropped the idea and turned to the shore. Little of that shore work is built. The Conservation Law Foundation found in April 2024 that most projects due by 2030 were still missing from the capital plan running to 2029.
🎓 Lesson
Boston turned its modelling into law faster than into concrete: the flood maps are public, machine-readable and binding on developers, while most of the seawalls and berms they justify are still drawings.
Evidence📊 Independent
Scale🏙️ City-wide
CostProgramme costs put at well over $4bn (Conservation Law Foundation, 2024); the 2026 USACE/City draft plan prices shoreline protection at $9-10.5bn
FundingCity of Boston capital budget, developer obligations under Article 80, state and federal grants; the harbour-barrier study was sponsored by the Boston Green Ribbon Commission
Sources
↗ Boston Research Advisory Group — Climate Change and Sea Level Rise Projections for Boston (authority, the modelling layer)The 2016 downscaled projections behind everything else, produced under UMass Boston's School for the Environment. Carries the 36 inches of sea-level rise as early as the 2070s, and the shift of severe flooding from roughly annual to monthly.
↗ UMass Boston ScholarWorks — the BRAG report deposited openly (academic repository)Confirms the projections are published in the open, not held as a consultant deliverable.
↗ City of Boston — Climate Ready Boston releases report, December 2016 (authority)Launch of the programme: climate projections, vulnerability assessment, resilience initiatives, by Arcadis, Sasaki, HR&A Advisors and UMass Boston.
↗ UMass Boston Sustainable Solutions Lab — Feasibility of Harbor-wide Barrier Systems, May 2018 (independent study)The study that ended the barrier idea. Recommended by the city in 2016, sponsored by the Boston Green Ribbon Commission. Finds the barriers do not address routine tidal flooding without frequent gate closures, and flags navigation, fisheries and ecosystem harm.
↗ WBUR — Study advises against Boston Harbor barriers, 30 May 2018 (press)Carries the numbers sentence-level: inner-harbour barrier 'could reach $8.7 billion', outer barrier 'up to $11.8 billion' over 3.8 miles from Winthrop to Hull, 'at least 30 years' to build. Lead author Paul Kirshen: 'Right now, it doesn't make sense for the city to consider any kind of harbor-wide barrier system.' City environment chief Austin Blackmon calls it 'affirmation that we're on the right track'.
↗ WBUR — Walsh outlines Resilient Boston Harbor, 17 October 2018 (press)The formal turn to the shore-based alternative five months after the study: elevated roads, berms and open space along the 47-mile shoreline instead of a barrier.
↗ Analyze Boston — Climate Ready Boston Sea Level Rise Inundation (open data, the licence check)The maps themselves, under the Open Data Commons Public Domain Dedication and License (PDDL), served as an ArcGIS GeoService REST API by Boston Maps. Scenarios: 9 inch (2030s), 21 inch (2050s), 36 inch (2070s), at high tide and at 10% and 1% annual exceedance probability. Released 22 September 2017, updated 8 July 2020.
↗ BPDA — Article 25A, Coastal Flood Resilience Overlay District (authority, the legal consequence)The overlay's own document set. Boundary is the modelled 1% annual chance flood in 2070 with 40 inches of sea-level rise; applies to Article 80 Large and Small Project Review; requires a Sea Level Rise Design Flood Elevation with one or two feet of freeboard by use sensitivity; uses below that elevation limited to access, flood prevention, storage and parking.
↗ A Better City — Article 25A explained (trade/civic, dates the adoption)BPDA board approval 13 September 2021, Zoning Commission adoption expected 13 October 2021; describes the new Resilience Review folded into Article 80.
↗ City of Boston — Coastal Resilience Implementation (authority, what is actually built)Completed: Martin's Park (2019), Langone Park and Puopolo Playground (2020), McConnell Park (July 2022), Piers Park Phase II (2023). In construction or design: Ryan Playground, Moakley Park, Tenean Beach, Lewis Street and Carlton Wharf, Long Wharf, Fort Point Channel. Run by the Office of Climate Resilience with the Planning and Parks departments.
↗ City of Boston — North End, Dorchester and South Boston park improvements completed, 2021 (authority)Langone Park and Puopolo Playground reopened February 2021 at about $15 million in public and private funds: inland secondary seawall, Harborwalk raised four feet, fields lifted out of the flood zone. The first Boston park built to the city's Climate Resilient Design Standards.
↗ Conservation Law Foundation — What happened to Climate Ready Boston?, 24 April 2024 (independent scrutiny)The counterweight: 'Most of the climate projects recommended for completion by 2030 have yet to be included in Boston's recent capital plans', including the plan through 2029; costs 'well over $4 billion'; leaning on developers is called 'an inefficient, piecemeal approach toward resilience'.
↗ City of Boston — Plan summary: Boston Coastal Storm Risk Management study, July 2026 (authority, currency)2026 currency: the joint US Army Corps of Engineers and City draft plan released 24 July 2026, comment to 18 September 2026, final to Congress in 2028. Shoreline protection across 16 of the 47 coastal miles in the five Climate Ready neighbourhoods, $9-10.5 billion against roughly $41 billion of prevented damage. Still shore-based, not a barrier.
📎 Cite this project
1001 Smart Cities (2026). “Climate Ready Boston” — Boston, United States. The Smart City Atlas. https://1001smartcities.org/projects/boston-climate-ready/. Data: CC BY 4.0.
The underlying data is free to reuse with attribution — see the open data page.
🔗 Related projects
🇺🇸 Miami Forever flood-resilience program · Miami
Two US coastal cities, two constraints: Miami prices a $3.8-5.4bn pump-and-seawall build; Boston zoned to its 2070 flood maps instead.
🇩🇰 Copenhagen's Cloudburst Management Plan · Copenhagen
Copenhagen has been building its 300+ rain projects since 2011; Boston turned its modelling into zoning law faster than into concrete.
🇺🇸 FloodNet street-level flood sensors · New York City
New York measures the water street by street; Boston modelled 36 inches of sea-level rise by the 2070s and wrote the map into its zoning.
🇺🇸 Analyze Boston and the 2014 Open Data Executive Order · Boston
Another verified project from Boston.
→ Open this project in the interactive atlas · → 🌱 Environment category · 🚩 Report an error