Ariz. Rev. Stat. § 45-171
Nothing in this chapter shall impair vested rights to the use of water, affect relative priorities to the use of water determined by a judgment or decree of a court, or impair the right to acquire property by the exercise of the right of eminent domain when conferred by law. The right to take and use water shall not be impaired or affected by the provisions of this chapter when appropriations have been initiated under and in compliance with prior existing laws and the appropriators have in good faith and in compliance with such laws commenced the construction of works for application of the water so appropriated to a beneficial use and prosecuted the work diligently and continuously, but the rights shall be adjudicated as provided in this chapter.
A.R.S. § 45-171