Utah Code § 23A-9-301: Diversion of water prohibited -- Exception for flood control.

(1) Except as provided in Subsection (2), a person may not, without existing rights, divert so much water from a natural stream, lake, pond, or natural lake or pond, the natural storage content of which has been increased by the construction of a dam, that the diversion unduly endangers protected aquatic wildlife.

(2) A person may divert waters in a manner that would otherwise violate Subsection (1) in anticipation of and to provide for the carrying away and the safe disposal of natural storm and flood waters.