S.D. Codified Laws § 46A-9-70
If, in the judgment of the board of directors, it is in the best interest of the water user district to sell any portion of the district works not needed for the performance of any outstanding contract, and not mortgaged or hypothecated as provided for in § 46A-9-71, the board of directors shall pass a resolution to that effect and shall submit the question to the Board of Water and Natural Resources for approval. If the Board of Water and Natural Resources approves, the board of directors shall call a special election at which the question of selling the portion of the works shall be submitted to the voters of the district qualified to vote for district directors. The board of directors shall mail to each qualified voter, at the voter's last known place of residence or place of business, a notice stating the time, place, and purpose of the election, and so far as practicable shall conduct the election in all other respects as provided in §§ 46A-9-25 to 46A-9-28, inclusive. If a majority of all qualified voters of the district vote "yes" at the election, the board of directors s may sell the portion of the works.
SDCL 46A-9-70