The City of Seattle has completed the first major update to the environmentally critical areas (ECAs) regulations since they were first adopted in 1992. These regulations address how development on and adjacent to Seattle’s ECAs is regulated. ECAs include the City’s wetlands, areas important for fish and wildlife such as riparian corridors (creeks) and shorelines, geologic hazard areas (such as landslide-prone, steep-slope and liquefaction-prone areas), flood-prone areas, and abandoned landfills.

The Mayor forwarded his ECA proposal to the City Council for consideration in September 2005. The City Council then reviewed, amended and on March 27, 2006, approved the ordinance. The new regulations will take effect on May 9, 2006.

Revisions to the ordinance increase protection for higher value wetlands through increased buffer sizes; provide greater protection for shoreline habitat by requiring mitigation for actions that harm habitat for fish and wildlife in proximity to these areas; and strengthen the protection of creek corridors by limiting development and encouraging more vegetation to be planted in these areas.

Major changes to the regulations include:

• increasing wetland buffers from the existing 50-foot requirement to as high as 200 feet, depending on the category and characteristics of the wetland
• increasing riparian corridor no-build buffers from the existing 50-foot requirement to 75 feet for larger streams that have anadromous fish such as salmon (Type 2 and 3), and to 50 feet for smaller streams (Type 4 and 5)
• potentially requiring the day-lighting of streams in limited circumstances
• establishing a new 100-foot shoreline habitat buffer, with mitigation required for the disturbance of habitat
• prohibiting pesticides and fertilizers within 50 feet of riparian corridors, wetlands and shorelines
• requiring formal variances for work on steep slopes
• reducing small project waiver areas, from 750 square feet to 150 square feet in riparian management areas and wetland buffers, to 300 square feet in steep slop areas and buffers