S.D. Codified Laws § 46A-9-26
Every owner of land and entryman within the district, and every person or corporation which is a party to a contract with the district for the purchase of water, for the collection, treatment, or disposal of wastewater, or other services to be furnished by the district, may cast one vote at each election for each director to be elected for whom the voter is entitled to vote. However, the vote which a voter is entitled to cast by reason of being a party to any such contract with the district is in addition to the vote to which the voter may be entitled by reason of being a landowner or entryman within the district. If election divisions are provided for, each person or corporation entitled to vote by reason of being a party to a contract, as provided in this section, shall select the division in which the person or corporation will vote. The selection shall be made under procedures established by resolution by the board of directors.
SDCL 46A-9-26