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Shoreline Management

Shorelines of statewide significance

The Shoreline Management Act (SMA) (RCW 90.58.030(2)(e)) defines a special category of shorelines where specific priority uses are preferred. These shorelines of statewide significance include:

Marine areas

There are three different delineation schemes for marine areas of statewide significance (Map):

  • The Pacific Ocean coastline (from Cape Disapointment to Cape Flattery), including harbors, bays, estuaries, and inlets, seaward from the ordinary high water mark and all shorelands associated with these waters;
  • Specific estuarine areas (Nisqually Delta, Birch Bay, Hood Canal, Skagit Bay, and Padilla Bay) between the ordinary high water mark and line of extreme low tide and all associated shorelands; and
  • All other areas of Puget Sound and the Strait of Juan de Fuca and adjacent salt water areas lying waterward of the line of extreme low tide line (but not including the adjacent tidelands or shorelands).

Streams and Rivers

Streams and Rivers, or segments thereof, and their associated uplands which meet one of the following criteria are shorelines of statewide significance:

  1. West of the Cascades crest: rivers with a mean annual flow of 1,000 cubic feet per second or greater,
  2. East of the crest of the Cascades crest: rivers that have either:
    1. a mean annual flow of 200 cubic feet per second or more, or;
    2. the portion downstream from the first 300 square miles of drainage areas

Specific river segments that meet this criteria are indicated with an asterisk (*) in the county-by-county descriptions in WAC 173-18.


Lakes over 1,000 acres in area and all associated shorelands are shorelines of statewide significance. Lakes of statewide significance are listed by county in WAC 173-20.

For more information

Law: RCW 90.58.030 (Definitions)