Shoreline, WA Invasive Plant Rules: Prohibited Species (2026)

Shoreline's critical areas chapter, SMC § 20.80.075(E), treats removal of noxious weeds and invasive vegetation identified on the Washington State or King County Noxious Weed Control Board lists as 'minor conservation and enhancement,' exempt from a critical area permit when it does not enlarge the disturbed footprint. The work must stay above the ordinary high-water mark, avoid very high risk landslide areas unless within a tree's critical root zone, and be performed with hand labor and handheld tools. Riding mowers, light mechanical cultivating equipment, herbicides, or biological controls are allowed only when the King County Noxious Weed Control Board prescribes them and the City approves the method on private property, or when the work follows SMC § 20.80.085 on City-owned land.

Removed plant material identified on the State or King County lists must be handled and disposed of using best management practices matched to that species. Replanting with site-appropriate native species at natural densities must happen immediately after removal. Property owners who clear more than 500 square feet of a critical area or buffer in a calendar year must submit a planting plan (work area, removal method, native planting plan and density, and project schedule) and a stormwater pollution prevention plan as part of a clearing and grading permit application.

The exemption does not excuse damage beyond what removal requires; any incidental alteration of the critical area must be restored, rehabilitated, or replaced at the responsible party's expense, and exceeding the exemption's scope is enforceable as an unauthorized critical area alteration under SMC § 20.80.090.