S.D. Codified Laws § 46A-2-37
The provisions of this chapter and chapters 46A-3A to 46A-3E, inclusive, do not abrogate or limit the rights, powers, duties, and functions of the State Water Management Board, but are supplementary to and in aid of such rights, powers, duties, and functions. Chapters 46A-3A to 46A-3E, inclusive, do not limit or affect the laws of this state relating to the organization and maintenance of irrigation districts, water user districts, drainage districts, soil conservation districts, or watershed districts. Chapters 46A-3A to 46A-3E, inclusive, do not infringe upon or establish any rights superior to any existing water rights, and do not preclude the establishment of any such or similar public entity wholly or in part within the boundaries of the district created by this chapter.
SDCL 46A-2-37