Federal Way, WA Environmental Rules: Boat Dock Permits (2026)

050(2), residential piers, docks, floats, or mooring buoys are allowed accessory to a single-family home, or as shared facilities for a subdivision or multifamily project, but the code caps what you can build. Only one pier, dock, float, or mooring buoy is permitted per existing residential lot, and new developments of two or more units must share a single dock rather than each unit getting its own. On the Puget Sound shoreline, a mooring buoy is the preferred option over a fixed structure, and an applicant proposing a dock or pier there must show why a buoy will not provide adequate moorage.

Dimensionally, a single-family pier or dock on marine shorelines cannot exceed 75 feet measured perpendicular from the ordinary high water mark (shared moorage can reach 100 feet if needed), the maximum width is six feet, walkway ramps top out at four feet, and decking must allow at least 45 percent light passage through grating or spacing. On lake shorelines the waterward limit is generally the average length of neighboring docks, capped at 36 feet or the point where water is eight feet deep, whichever comes first.

No structure may protrude more than five feet above the water surface, floats cannot rest on the substrate, chemically treated wood is barred on freshwater lakes and creosote-treated wood on marine shorelines, and no dwelling unit may be built on a pier or dock. Live-aboard vessels are prohibited except for temporary habitation in a cabin under the hull, capped at 14 days in any six-month period. A preliminary eelgrass survey under Army Corps Regional General Permit RGP 6 is required for new Puget Sound docks or piers, and side and rear yard setbacks of the underlying zone apply except for shared facilities.