This chapter does not apply to the merger of irrigation districts authorized under RCW 87.03.530(2) and 87.03.845 through 87.03.855 or to the merger of a drainage improvement district, joint drainage improvement district, or consolidated drainage improvement district into an irrigation district authorized by RCW 87.03.720 through 87.03.745 and 85.08.830 through 85.08.890.