S.D. Codified Laws § 13-6-13.1
When the reorganization plan is submitted, the school board or the electors of the district may establish school board representation areas to represent each former school district that consolidated to form the reorganized school district. Each former school district representation area shall be formed by adhering to standards of population deviance as established by judicial precedence. The former school district representation areas shall be established after an election is called and held pursuant to §§ 13-8-3 to 13-8-5, inclusive, by a majority vote of the electors voting at the election. The former school district representation areas, if established, shall become effective January first of the following year. If former board member representation areas are established, the school board member candidate shall be a resident voter and reside within the representation area to qualify. The reorganization plan shall state whether the school board member candidates shall be elected at large or elected by the voters who reside within the representation area.
Any current board members shall serve the balance of their term. At the time of an election or vacancy, board members shall be elected or appointed in order that each representation area shall have a resident board member.
SDCL 13-6-13.1