SDCL § 46-6-1: Vested rights defined.

The term, vested rights, as used in this chapter, means:

(1) Beneficial uses of groundwater under diversions and applications of water before February 28, 1955;

(2) The right to take and use groundwater for beneficial purposes if an owner or lawful agent was engaged in the construction of works for the actual application of water to a beneficial use on February 28, 1955, if the works are completed and water is actually applied for such use within a reasonable time after that date.