S.D. Codified Laws § 46A-14-5
Any proceeding for the establishment of a watershed district shall be initiated by the filing of an initiating petition with each conservation district in which the proposed watershed district is located. The initiating petition shall be as provided in § 6-16-2. If the proposed watershed district includes land in more than one conservation district, the supervisors of each such conservation district shall act jointly as a board of supervisors on all matters concerning the watershed district that are specified in this chapter for a single conservation district.
An official of any municipality authorized by resolution of the governing body may sign the petition on behalf of the municipality if land located within the boundaries of the municipality is to be included in the watershed district. The petition need not be signed by any of the property owners of the municipality.
SDCL 46A-14-5