Wash. Rev. Code § 17.04.250
The county treasurer shall be ex officio treasurer of such district and the county assessor and other county officers shall take notice of the formation of such district and of the tax levy and shall extend the tax on the tax roll against the property liable therefor the same as other taxes are extended, and such tax shall become a general tax against such property, and shall be collected and accounted for as other taxes, with the terms and penalties thereto attached. The moneys collected from such tax shall be paid into a fund to be known as "fund of weed district . . . . . . of . . . . . . county" (giving the number of district and name of county). All expenses in connection with the operation of such district, including the expenses of initial and annual meetings, shall be paid from such fund, upon vouchers approved by the board of directors of such district.
RCW 17.04.250