S.D. Codified Laws § 46A-3A-15
If all of the election districts within a proposed water development district become a part of the water development district as provided in this chapter on approval of the proposed district by sixty percent or more of the votes cast in the election districts, or if the Board of Water and Natural Resources establishes a water development district pursuant to the provisions of § 46A-3A-14 for which not all of the election districts become a part of the water development district, the board shall by resolution create and establish the water development district, give it a name and, upon filing a true copy of the resolution with the secretary of state, the water development district shall become a political subdivision of the state with the authority, powers, and duties prescribed by this chapter.
SDCL 46A-3A-15