Wash. Rev. Code § 35A.14.450
Upon the date fixed in the ordinance of annexation, the area annexed shall become part of the city. All property within the annexed territory shall, if the annexation petition so provided, be assessed and taxed at the same rate and on the same basis as the property of the annexing code city is assessed and taxed to pay for the portion of any then-outstanding indebtedness of the city to which the area is annexed, which indebtedness has been approved by the voters, contracted for, or incurred before, or existing at, the date of annexation and that the city has required to be assumed. If the annexation petition so provided, all property in the annexed area shall be subject to and a part of the proposed zoning regulation as prepared and filed as provided for in RCW 35A.14.330 and 35A.14.340.
RCW 35A.14.450
Intent-Severability-Effective date-2003 c 331: See notes following RCW 35.13.410.