Permanent project revision
Revision 2026-08-20-source-dates · effective 2026-07-26
Current revision. This is the snapshot used by the live entity page.
Created the first structured Evidence Passport with 1 claim and 13 source dossiers.
sha256:38a11a01cf3bf5d246e54b0f1b5404e5136b8659896b8b89e7a373eab9605ecb
add /evidencePassport — Added claim-level evidence mapping and source dossiers.add /revisionHistory — Established a permanent, hash-addressed baseline revision.The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.
clm-a5e9e8025c648473
quantitative
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
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sha256:38a11a01cf3bf5d246e54b0f1b5404e5136b8659896b8b89e7a373eab9605ecb
src-58bf52c9603e2b0aThe 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.
src-7bab6aa9565e0f51Confirms the projections are published in the open, not held as a consultant deliverable.
src-c07cdc75be4f9475Launch of the programme: climate projections, vulnerability assessment, resilience initiatives, by Arcadis, Sasaki, HR&A Advisors and UMass Boston.
src-2f517cc2acf9f45fThe 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.
src-2a39a2cfd78629e0Carries 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'.
src-d11bc19a86fff05aThe 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.
src-c3fe2d126da76b82The 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.
src-ef8e077e69772376The 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.
src-c8f151e75edcb88fBPDA board approval 13 September 2021, Zoning Commission adoption expected 13 October 2021; describes the new Resilience Review folded into Article 80.
src-dbfd91d3a580e541Completed: 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.
src-034c5bbd8882a375Langone 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.
src-e886914437109b0eThe 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'.
src-8c9df50b65cb376e2026 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.