Seattle public GIS
Seattle ECA map and layer guide.
How to check the city's environmentally critical area layers, download the address-level Site Characteristics Report, and understand what neither source can establish by itself.
Check a Seattle address in three steps
Open the official ECA map
Search the address in the SDCI Property Information Map ↗ and turn on the relevant environmentally critical area layers. Treat a mapped flag as a screening signal, not a surveyed boundary or stability finding.
Download the Site Characteristics Report
Use SDCI's Permit & Site History Research Tool ↗ to locate the development site and download its current report. Review related addresses, zoning overlays, permit history and available documents together.
Move from screening to the project path
Map layers and reports do not approve a wall or diagnose a slope. Continue with the Seattle ECA retaining-wall guide, then decide whether the first call belongs with an engineer, contractor or agency and trace any proposed outlet with the Seattle wall-drainage guide.
What the aggregates describe
Each neighborhood profile intersects an official Neighborhood Map Atlas polygon with four Seattle environmentally critical area layers: steep slope, potential slide areas, properties associated with known slides, and liquefaction-prone areas. It also counts known-slide initiation points inside the same neighborhood polygon and reports event years when the source carries a usable date.
Percentages are calculated from simplified GeoJSON at refresh time and rounded to two decimal places. Boundaries overlap imperfectly with everyday neighborhood usage and permit labels. Use the values to understand the citywide record, not to rank homes, predict a slide, or decide whether engineering is required.
Planning a retaining-wall repair or replacement on a flagged site? Read the Seattle ECA and steep-slope wall guide for the permit test, map limitations, relief paths, survey and geotechnical roles, drainage, and rainy-season review.
Neighborhood layer profiles
Each ECA aggregate now lives in the single combined profile for that Seattle neighborhood. These links open the layer section directly; there is no separate set of duplicate slope-detail pages.