Wash. Rev. Code § 35.85.030
The city council may prescribe by general ordinance, the mode and manner in which the charge upon property in such local improvement district shall be assessed and determined for the purpose of paying the cost and expense of establishing and constructing such improvement: PROVIDED, That no assessment shall be levied on any such district, the aggregate of which is a greater sum than twenty-five percent of the assessed value of all the real property in such district according to the last equalized assessment thereof for general taxation: PROVIDED FURTHER, That there shall be, in all cases, an opportunity for a hearing upon objections to the assessment roll by the parties affected thereby, before the council as a board of equalization, which hearing shall be after publication of a reasonable notice thereof, such notice to be published in such manner and for such time as may be prescribed by ordinance. At such hearing, or at legal adjournments thereof, such changes may be made in the assessment roll as the city council may find necessary to make the same just and equitable. Railroad rights-of-way shall be assessed for such benefits as shall inure or accrue to the owners, lessees, or operators of the same, resulting or to result from the construction and maintenance of any such improvement, whether such rights-of-way lie within the limits of any street or highway or not; such assessment to lie against the franchise rights when such right-of-way is within such street or highway.
When the assessment roll has been finally confirmed by the city council, the charges therein made shall be and become a lien against the property or franchise therein described, paramount to all other liens (except liens for assessments and taxes) upon the property assessed from the time the assessment roll shall be placed in the hands of the collector.
RCW 35.85.030