In the event said hearing shall result in a determination that in the discretion of the directors of said irrigation district it is advisable that said assessments be segregated and apportioned among the various parcels of said tracts against which the original total assessment was levied, then an order shall be entered on the records of the directors of said irrigation district determining said segregation, and a certified copy thereof shall be filed with the county treasurer of the county in which said assessment roll is filed.
RCW 87.03.300