Wash. Rev. Code § 70.44.370
After adoption of a resolution approving the plan of division by the board of commissioners of an existing district pursuant to RCW 70.44.350 through 70.44.380, the district shall petition the superior court in the county where such district is located requesting court approval of the plan. The court shall conduct a hearing on the plan of division, after reasonable and proper notice of such hearing (including notice to bondholders) is given in the manner fixed and directed by such court. At the conclusion of the hearing, the court may enter its order approving the division of the existing district and of its assets and outstanding obligations in the manner provided by the plan after finding such division to be fair and equitable and in the public interest.
RCW 70.44.370