RCW 86.09.625

When the obligations have been fully paid, all moneys in any of the funds of the district and all collections of unpaid district assessments shall be transferred to the general fund of the county within which the major portion of the district is situated as partial reimbursement for moneys expended and services rendered by the county for and in behalf of the district, and thereupon the county legislative authority of that county shall file a statement of the full payment of the district's obligations for record in the county auditor's office in each county in which any lands in the district were situated and thereafter the dissolution of the district shall be complete and its corporate existence ended.