Wash. Rev. Code § 87.68.010
At the option of the board of directors assessments of irrigation districts in this state under contract with the United States involving payments thereto for the development and operation of their respective projects shall be payable on or before December 31st of the year in which the assessment is levied and upon the resolution of the board of directors of the district to that effect, adopted and entered at a regular meeting thereof not later than the second Tuesday of September of the year in which the levy is made. Such resolution shall thereafter remain in full force and effect until revoked by the board.
RCW 87.68.010
Severability-1941 c 141: "If any section, provision or part of this act shall be adjudged to be invalid or unconstitutional, such adjudication shall not affect the validity of the act as a whole or of any section, provision, or part thereof not adjudged invalid or unconstitutional." [ 1941 c 141 s 7.]
Construction-1941 c 141: "Nothing in this act contained shall be held or construed to modify, abridge or extend any other law or provision thereof relating to irrigation district assessments or the collection thereof except as herein provided." [ 1941 c 141 s 6.]