S.D. Codified Laws § 46-5-5 (2026)
Subject to vested rights and prior appropriations, all waters flowing in definite streams of the state may be appropriated only as provided in chapters 46-1 to 46-10, inclusive. A water right does not constitute absolute ownership of the water, but shall remain subject to the principle of beneficial use. No appropriation in excess of the reasonable needs of the appropriators may be allowed.
Source: SDC 1939, § 61.0102; SL 1955, ch 430 , § 1; SDC Supp 1960, § 61.0109; SL 1983, ch 314 , § 42.