About TideGateway
TideGateway is a public website for exploring tide gate infrastructure across the Massachusetts Bays region (with a focus on Greater Boston and nearby coastal communities). It brings together historic inventories and the latest field surveys to support wetland restoration, flood resilience, and informed decision-making.
Who we are
TideGateway is a collaborative effort of the Massachusetts Bays National Estuary Partnership (MassBays) and the Massachusetts Office of Coastal Zone Management (CZM), with contributions from regional partners. The project has been partially supported by an NOAA grant and is designed for local, state, and federal resource managers, researchers, and community stakeholders.
What this site provides
- Tide Gate Inventory – A searchable catalog of individual tide gates with standardized attributes, photos, permits, and related documents.
- Interactive Map – A web map to locate tide gates and view them in context with wetlands, floodplains, and other ecological layers.
- Detail Pages – Read-only summaries for each site: ownership/operations, structure type and condition, culvert characteristics, notes, photos, and links to source material.
- Field Protocol Handbook – Guidance on how field teams assess sites and record observations.
- Field Collection Tool – A mobile-friendly workflow that allows authorized staff to submit site updates (notes, geolocation, photos) directly from the field for review.
Why tide gates matter
Tide gates influence tidal exchange, salinity, sediment movement, and habitat connectivity. As sea level rises and storms intensify, understanding where and how these structures operate helps communities manage flooding, protect infrastructure, and restore salt marshes and other tidal wetlands.
What's in the data
New survey (2024–2025)
Our most recent field campaign added and updated site records across communities such as Salem, Revere, and Marshfield. Observations capture both marsh condition and channel form, including (examples):
- Channel & sediment: alteration/ditching, constriction, erosion, in-channel deposits, debris/blockages, evidence of overtopping.
- Habitat proximity (yds): distance to open water, salt marsh, native brackish vegetation, freshwater wetlands, ditch networks, and unvegetated areas; open-water percent where noted.
- Biological indicators: Phragmites (common reed) presence, crab burrow intensity, ponding and die-off depressions, invasive species upstream/downstream, and comments on ecological impairment due to tidal restriction.
- Photos & notes: captioned imagery, structured notes, and timestamps.
- Location: latitude/longitude in decimal degrees.
You will see "Inspectors," "Creation/Edit date," and other provenance fields to help track when and how each record was created or updated.
Historic inventory
Earlier site assessments (e.g., Cape and South Shore towns) remain available for continuity and comparison. These records often include:
- Structure & operation: gate type (e.g., flap gates, stop logs), control mechanism, geometry and dimensions, number of gates, installation date/status, operational purpose and plan, invert elevation (often NAVD88), tidal influence upstream/downstream, and condition.
- Culvert details: geometry, dimensions, materials (pipe and bottom), condition, number of pipes, and comments.
- Permitting & ownership: operator type/agency, permits (e.g., Chapter 91, 401 WQC), and operational manuals where available.
- Marsh condition & restoration: invasive species notes, upstream marsh extent, restoration status/comments.
- Media & references: photo sets with annotations and links to external documents.
Where possible, we align historic fields with the modern schema so you can filter and compare across time.
Data stewardship & update cycle
- Quality control: New submissions from the Field Collection Tool enter a review queue. Staff verify location, attributes, and media before publishing.
- Versioning: We retain history for key fields so you can trace changes over time.
- Refresh cadence: Survey-based updates are incorporated after each field round; minor edits (e.g., metadata corrections) may occur between campaigns.
- Coordinates & elevation: Locations are stored in WGS84 (EPSG:4326). Elevations provided in legacy records typically reference NAVD88 when available.
- Known limitations: Some fields appear only in legacy records or only in new surveys; a few historic links and photos may point to external archives.
Acknowledgments
We thank MassBays, CZM, NOAA, municipal partners, and the field teams and engineers who contributed survey data, photos, and documentation across the region.
Contact & feedback
Questions, corrections, or new information about a site?
Please reach out to the project team via the Contact link in the footer. For data issues, include the Tide Gate Name and the record timestamp shown on the detail page.
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.