Washington Revised Code Title 35A. Optional Municipal Code § 35A.08.010. Adoption of charter authorized

Any city having a population of ten thousand or more inhabitants may become a charter code city and be governed under the provisions of this title by adopting a charter for its own government in the manner prescribed in this chapter. Once any city, having ten thousand population, has adopted such a charter, any subsequent decrease in population below ten thousand shall not affect its status as a charter code city.