Wash. Rev. Code § 89.12.090
Whenever a district to which this chapter applies is organized or in process of organization, the state of Washington, by and through its proper officials, is authorized and directed to have any state lands within the exterior boundaries of such district included as a part of the lands of such district. The state hereby consents to the assessment by the district of such state lands so included in any such irrigation district, and to the enforcement of the payment of such assessments in like manner and to the same extent as applicable to private lands in such districts, except that the payment of such assessment against such state lands shall not be enforced by transfer of title, by tax sale, tax foreclosure or otherwise, until the state has sold or transferred such lands to a private party.
RCW 89.12.090