SDCL § 9-13-25: Election result--Highest vote total or runoff.

Except as otherwise provided in this section, the person having the highest number of votes for any municipal office is elected.

The governing body of any municipality may, by ordinance enacted at least six months before the election, require a runoff election to be conducted pursuant to §§ 9-13-26.1 and 9-13-27.1.