S.D. Codified Laws § 9-43-86

Twenty days after publication of the adopted resolution of necessity, unless the referendum is invoked or unless a written protest is filed with the finance officer signed by the owners of more than fifty-five percent of the frontage of the property to be assessed, the governing body may cause the local improvement to be made, may contract for the improvement, and may levy and collect special assessments as provided in this chapter. Upon a two-thirds vote of the governing body, a protest petition may be denied and the governing body may cause the local improvement to be made.