Wash. Rev. Code § 87.03.025
Whenever public lands of the state are situated in or taken into an irrigation district they shall be treated the same as other lands, except as hereinafter provided. The commissioner of public lands shall be served with a copy of the petition proposing to include such lands, together with a map of the district and notice of the time and place of hearing thereon, at least thirty days before the hearing, and if he or she determines that such lands will be benefited by being included in the district he or she shall give his or her consent thereto in writing. If he or she determines that they will not be benefited he or she shall file with the board a statement of his or her objections thereto.
Any public lands of the state which are situated within the boundaries of an irrigation district, but which were not included in the district at the time of its organization, may be included after a hearing as herein provided.
Whenever the commissioner or any interested person desires to have state public lands included in an existing district, he or she shall file a request to that effect in writing with the district board, which shall thereupon fix a time and place for hearing the request and post notice thereof in three public conspicuous places in the district, one of which shall be at the place of hearing, at least twenty days before the hearing, and send by registered mail a copy of the notice to the commissioner. The notice shall describe the lands to be included and direct all persons objecting to such inclusion to appear at the time and place stated and present their objections. At the hearing the district board shall consider all objections and may adjourn to a later date, and by resolution determine the matter, and its determination shall be final: PROVIDED, That no such lands shall be included in a district without the written consent of the commissioner of public lands.
Any public lands of the state situated in any irrigation district shall be subject to the provisions of the laws of this state relating to the collection of irrigation district assessments to the same extent and in the same manner in which lands of like character held under private ownership are subject thereto, but collection and payment of the assessments shall be governed solely by the provisions of chapter 79.44 RCW.
RCW 87.03.025
Irrigation district assessments: RCW 87.03.240 through 87.03.305.