Wash. Rev. Code § 87.03.270
The assessment roll, before its equalization and adoption, shall be checked and compared as to descriptions and ownerships, with the county treasurer's land rolls. On or before the fifteenth day of January in each year the secretary must deliver the assessment roll or the respective segregation thereof to the county treasurer of each respective county in which the lands therein described are located, and said assessments shall become due and payable after the county treasurer has completed the property tax roll for the current year's collection and provided the notification required by RCW 84.56.020.
All assessments on said roll shall become delinquent on the first day of May following the filing of the roll unless the assessments are paid on or before the thirtieth day of April of said year: PROVIDED, That if an assessment is ten dollars or more for said year and if one-half of the assessment is paid on or before the thirtieth day of April, the remainder shall be due and payable on or before the thirty-first day of October following and shall be delinquent after that date. All delinquent assessments shall bear interest at the rate of twelve percent per annum, computed on a monthly basis and without compounding, from the date of delinquency until paid.
Upon receiving the assessment roll the county treasurer shall prepare therefrom an assessment book in which shall be written the description of the land as it appears in the assessment roll, the name of the owner or owners where known, and if assessed to the unknown owners, then the word "unknown", and the total assessment levied against each tract of land. Proper space shall be left in said book for the entry therein of all subsequent proceedings relating to the payment and collection of said assessments.
On or before April 1st of each year, the treasurer of the district shall send a statement of assessments due. County treasurers who collect irrigation district assessments may send the statement of irrigation district assessments together with the statement of general taxes.
Upon payment of any assessment the county treasurer must enter the date of said payment in said assessment book opposite the description of the land and the name of the person paying and give a receipt to such person specifying the amount of the assessment and the amount paid with the description of the property assessed.
It shall be the duty of the treasurer of the district to furnish upon request of the owner, or any person interested, a statement showing any and all assessments levied as shown by the assessment roll in his or her office upon land described in such request. All statements of irrigation district assessments covering any land in the district shall show the amount of the irrigation district assessment, the dates on which the assessment is due, the place of payment, and, if the property was sold for delinquent assessments in a prior year, the amount of the delinquent assessment and the notation "certificate issued": PROVIDED, That the failure of the treasurer to render any statement herein required of him or her shall not render invalid any assessments made by any irrigation district.
It shall be the duty of the county treasurer of any county, other than the county in which the office of the board of directors is located, to make monthly remittances to the county treasurer of the county in which the office of the board of directors is located covering all amounts collected by him or her for the irrigation district during the preceding month.
When the treasurer collects a delinquent assessment, the treasurer shall collect any other amounts due by reason of the delinquency, including accrued costs, which shall be deposited to the treasurer's operation and maintenance fund.
RCW 87.03.270
Effective date-1982 c 102: "This act is necessary for the immediate preservation of the public peace, health, and safety, the support of the state government and its existing public institutions, and shall take effect April 15, 1982." [ 1982 c 102 s 3.]
Effective date-1981 c 209: See note following RCW 87.03.215.
Assessments
districts under contract with United States: Chapter 87.68 RCW.
how and when made-Assessment roll: RCW 87.03.240.
Equalization of assessments: RCW 87.03.255.
Evidence of assessment, what is: RCW 87.03.420.