The first step in determining shoreline jurisdiction is identifying which shorelines are regulated by the State Shoreline Management Act (SMA).  According to the SMA, the City's SMP regulations apply to all 'shorelines of statewide significance', 'shorelines', and their adjacent 'shorelands'^1.

Generally, 'shorelines of statewide significance' include portions of Puget Sound and other marine water bodies, rivers wet of the Cascade Range that have a mean annual flow of 1,000 cubic feet per second (cfs) or greater, rivers east of the Cascade Range that have a mean annual flow of 200 cfs or greater, and freshwater lakes with a surface area of 1,000 acres or more.

'Shorelines' are defined as streams or rivers having a mean annual flow of 20 cfs or greater and lakes with a surface area of 20 acres or greater.

'Shorelands' are defined as the upland area within 200 feet of the ordinary high water mark (OHWM) of any shoreline or shoreline of statewide signicance; floodways and contiguous floodplain areas landward 200 feet from such floodways; and all associated wetlands and river deltas.

'Associated wetlands' means those wetlands that are in proximity to and either influence or are influenced by waters subject to the SMA.²  The figure below graphically illustrates how floodways, floodplains, and associated wetlands influence the extent of SMA shoreline jurisdiction within a riverine environment (such as Muck Creek).

Muck Lake and Muck Creek meet the designation criteria for 'shorelines of the state'.  These shoreline jurisdiction areas (preliminary) are shown in Maps 1a and 1b of the Draft Shoreline Inventory and Characterization Report.

¹ RCW 90.58.030

² WAC 173-22-0360(1)