Wash. Rev. Code § 52.04.161
If the area of a newly incorporated city or town is located in one or more fire protection districts, the city or town is deemed to have been annexed by the fire protection district or districts effective immediately on the city's or town's official date of incorporation, unless the city or town council adopts a resolution during the interim transition period precluding the annexation of the newly incorporated city or town by the fire protection district or districts. The newly incorporated city or town shall remain annexed to the fire protection district or districts for the remainder of the year of the city's or town's official date of incorporation, or through the following year if such extension is approved by resolution adopted by the city or town council and by the board or boards of fire commissioners, and shall be withdrawn from the fire protection district or districts at the end of this period, unless a ballot proposition is adopted by the voters providing for annexation of the city or town to one fire protection district or providing for the fire protection district or districts to annex only that area of the city or town located within the district. Such election shall be held pursuant to RCW 52.04.071 where possible, provided that in annexations to more than one fire protection district, the qualified elector shall reside within the boundaries of the appropriate fire protection district or in that area of the city located within the district.
If the city or town is withdrawn from the fire protection district or districts, the maximum rate of the first property tax levy that is imposed by the city or town after the withdrawal is calculated as if the city or town never had been annexed by the fire protection district or districts.
RCW 52.04.161