Wash. Rev. Code § 85.06.550
When any drainage district has been or shall be established and created under the provisions of an act of the legislature of the state of Washington, entitled "An act to provide for the establishment and creation of drainage districts, and the construction and maintenance of a system of drainage, and to provide for the means of payment thereof, and declaring an emergency", approved *March 20, 1895, and when the drainage commissioners of such district have employed surveyors or drafters, or legal assistance as provided in RCW 85.06.100, and have incurred expenses for the compensation of such surveyors, drafters, and legal assistance, and have issued to such surveyors, drafters, or persons rendering said legal assistance any warrants, orders, vouchers, or other evidence of indebtedness for said expenses so incurred, and when such warrants, orders, vouchers, or other evidences of indebtedness remain outstanding and unpaid, and when from any cause no further proceedings are had as provided for in said act approved *March 20, 1895, within a reasonable time, it shall be the duty of the county commissioners of the county in which such drainage district is located to assess in accordance with the provisions of RCW 85.06.550 through 85.06.630, the lands constituting and embraced within such drainage district for the purpose of paying such outstanding warrants, orders, vouchers, or other evidences of indebtedness, together with interest thereon.
RCW 85.06.550
*Reviser's note: The act of "March 20, 1895" is chapter 115, Laws of 1895, the basic drainage district law, codified as Part I of chapter 85.06 RCW as it has been amended and added to.