Water appropriated under an existing right or pursuant to this chapter may be turned into the natural channel of another stream or from a reservoir into the natural channel and withdrawn or diverted at a point downstream for beneficial use, but the waters of that stream may not thereby be diminished in quantity or deteriorated in quality to the detriment of a prior appropriator. Water stored in a reservoir under an existing right or pursuant to this chapter which is turned into a natural channel for withdrawal or diversion and beneficial use downstream shall not be considered a part of the natural flow of that stream.
§ 85-2-411, MCA