RCW 87.03.295

Not less than ten days prior to the time and date fixed for said hearing the directors of said irrigation district shall cause notice of the time and place of said hearing to be given by registered mail to every person, firm or corporation having any interest in said property as shown by the county assessor's records or by the record of the irrigation district within which said property is located and to the address shown by said records, authorizing and directing that they appear and be heard at said time and place.