Wash. Rev. Code § 89.16.070
A diking, drainage, diking and drainage, and irrigation district, and improvement districts thereof through the parent district, or such other district as is authorized and organized for the reclamation or development of waste or undeveloped lands, may enter into contracts with the director for the reclamation of the lands of the district in the manner provided herein, or in such manner as such districts may contract with the United States or with individuals or corporations, for making surveys and furnishing engineering plans and supervision for the construction of all works and improvements necessary for the reclamation of its lands, and for the sale or delivery of its bonds, and may issue bonds of the district for such purposes.
RCW 89.16.070