S.D. Codified Laws § 1-41-15
There is created a Water Management Board within the Department of Agriculture and Natural Resources. The board shall consist of seven members to be appointed by the Governor for a term of four years, and no more than four members shall be of the same political party. The terms of members of the Water Management Board who are first appointed after the effective date of this order shall be: two appointed for a term of one year; two appointed for a term of two years; two for a term of three years; and one for a term of four years, and such initial terms are to be designated by the Governor. Any member appointed to fill a vacancy arising from other than the natural expiration of a term shall serve for only the unexpired portion of the term.
SDCL 1-41-15