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Critical areas are lands with natural hazards or lands that support certain unique, fragile or valuable resource areas.

Lands designated by King County as critical include areas at high risk for erosion, landslides, earthquakes or flooding; coal mines; or wetlands or lands adjoining streams, rivers and other water bodies.

The King County Code protects critical areas as well as their buffers in order to protect public health and safety, and to promote environmental health in the region. Buffers are areas adjacent to a critical area that are also restricted from specific building and development activities.

When a development proposal occurs near wetlands, lakes, wildlife habitat or streams, an applicant may be asked to provide additional information with the permit application in order to enable the Department of Local Services, Permitting Division (Permitting) staff to better assess potential impacts the development might have on these critical areas.

Critical areas designation

A Critical Areas Designation is a process that allows a property owner to define the limits of critical areas on or near the project site, establish buffers and other required mitigation measures.

Critical area alteration exception

A critical area alteration process allows adjustments in the application of zoning code standards related to critical area buffers to a particular property.

Reasonable use exception

A reasonable use exception (RUE) is used only when all reasonable uses of a site, as allowed by adopted zoning, is denied as result of critical areas.

Additional resources and information: