As used herein:
(1) "Governmental unit" means any incorporated city or town, metropolitan municipal corporation, or any special purpose district as defined in this section.
(2) "Special purpose district" means any water-sewer district, fire protection district, drainage improvement district, drainage and diking improvement district, flood control zone district, irrigation district, metropolitan park district, drainage district, or public utility district engaged in water distribution.
(3) "Board" means a boundary review board created by or pursuant to this chapter.