Dictionary.net

An appropriation of water flowing on the public domain consists in the capture, impounding, or diversion of it from its natural course or channel and its actual application to some beneficial use private or personal to the appropriator. to the entire exclusion (or exclusion to the extent of the water appropriated) of all other persons. To constitute a valid appropriation, there must be an intent to apply the water to some beneficial use existing at the time or contemplated in the future. a diversion from the natural channel by means of a ditch or canal, or some other open physical act of taking possession of the water, and an actual application of it within a reasonable time to some useful or beneficial purpose. Low v. Rlzor. 25 Or. 551, 37 Pac. 82; Clough v. Wing. 2 Ariz. 371. 17 Pac. 453: Offield v. Ish, 21 Wash. 277. 57 Pac. 809; Reservoir Co. v. People. 8 Colo. 014. 9 Pac. 794; McCall v. Porter. 42 Or. 49, 70 Pac. 820; McDonald v. Mining Co., 13 Cal. 220.