Wash. Rev. Code § 85.24.900
The organization, establishment and creation of all diking and drainage districts in this state situated in two or more counties heretofore had or made, or attempted to be had or made, pursuant to the provisions of chapter 4, Title XXVII of Remington's Compiled Statutes, relating to the creation and establishment of such diking and drainage districts, and all acts, steps or proceedings had or attempted to be had by any such district, are hereby for all purposes declared legal and valid, and such districts situated in two or more counties are hereby declared duly organized, established and created, and all contracts, obligations or debts heretofore made or incurred by or in favor of such diking and drainage district situated in two or more counties so attempted to be organized, established and created, and all official bonds or other obligations executed in connection with or in pursuance of such organization, are hereby declared legal and valid, and of full force and effect.
RCW 85.24.900