(1) Except as provided in subsection (2) of this section, certificates of delinquency shall also be issued, and foreclosure proceedings instituted under this chapter, for properties for which assessments have been delinquent for a period of three or more years, if all or part of such period occurred before June 9, 1988. If foreclosure actions have been commenced but not completed under the law as it existed prior to June 9, 1988, the district shall abandon such actions and proceed against such properties under this chapter.

(2) Certificates of delinquency shall not be issued under this chapter for properties that have been sold (other than to the irrigation district) under foreclosure proceedings which occurred prior to June 9, 1988. This section does not apply to any foreclosure sale declared to be invalid by a court of competent jurisdiction or if district assessments again become delinquent after the date of sale.

(3) A certificate of delinquency may be issued, and foreclosure proceedings instituted, under this chapter for property acquired by an irrigation district under foreclosure proceedings which occurred prior to June 9, 1988, and which the district believes might be legally defective. "Acquired" as used in this subsection also includes the district's obtaining a certificate of sale under such foreclosure proceedings.