Wash. Rev. Code § 87.80.060
The notice of the hearing on the petition shall state that a petition requesting the creation of a board of joint control to administer the facilities and activities, naming them if named in the petition, has been filed with the board of county commissioners of the county, naming the county; that the board of joint control, if it is created, will have authority to provide for apportionment of costs to carry out the objects of its creation among the member irrigation entities (naming them); shall state the day, hour, and place of the hearing on the petition; shall state that any person interested in the creation of the board of joint control may appear on or before the day of hearing on the petition, and show cause in writing, if any, why the same should not be granted, and the notice shall be over the name of the clerk of the board of county commissioners.
RCW 87.80.060