Notwithstanding § 46A-10A-43, if within ten years prior to July 1, 1985, three or more landowners have jointly maintained a legal drain by voluntarily contributing the cost of maintenance without establishing a drainage district or without special assessments as provided in chapter 46A-11, the landowners may petition the board to provide for future maintenance, improvement, and repair of the drain.
SDCL 46A-10A-43.1