SDCI has updated the Environmentally Critical Areas (ECA) Map for Liquefaction-Prone areas. Liquefaction occurs when loose, saturated soils lose their strength due to strong ground shaking (usually from earthquakes). Details of the update are described in Director’s Rule 2-2023, Update of ECA Liquefaction-Prone Areas Map, which was effective August 30, 2023. You can view the new liquefaction-prone ECA layer on our GIS map.
Seattle DCI will post the updated advisory map for steep slope environmentally critical areas on October 24, 2016. The updated map will replace the steep slope layer shown on our GIS application.