Indiana Code Title 14. Natural and Cultural Resources § 14-25-1-4

Sec. 4. (a) This section applies to land contiguous to or encompassing a public watercourse.

(b) The:

may impound the water behind a dam in the natural stream bed or on the owner's land or by pumping or diverting the water from a stream or lake to a reservoir when the flow in the stream or the level of the lake exceeds existing reasonable uses at the time of the impoundment.

(c) An obstruction placed across a natural stream must include an outlet facility for release of water that the owner is not entitled to use under this chapter.  The owner shall operate the outlet in accordance with this section.

(d) Action by an owner or a group of owners under this section must be approved by the commission before the action is taken.