Whenever in the discretion of the board of directors of any irrigation district of the state as determined by resolution, after an assessment roll has been filed with the county treasurer of the appropriate county in accordance with the laws of the state pertaining thereto, the irrigation district assessments against any tract or parcel of land may be segregated to apply against, and the lien may be divided among, the various parcels of said tract as the same may be hereafter divided, all in accordance herewith.