What does the phrase "use it or lose it" signify in Arizona water law?

The phrase "use it or lose it" in Arizona water law signifies that water rights may be forfeited if they are not used beneficially. This principle is rooted in the doctrine of beneficial use, which is the cornerstone of water rights in Arizona. According to this doctrine, simply holding a water right without actively using it for a beneficial purpose—such as agriculture, industrial, or municipal needs—can lead to a loss of that right. The rationale behind this rule is to encourage the effective and responsible use of water resources, ensuring that they are utilized to meet the needs of the population and the environment, rather than being held in reserve without any practical application.

In contrast, while water rights can technically be sold, this is separate from the principle of "use it or lose it." The need for continuous use does apply, but it aligns more with the concept of forfeiture rather than just a continuous water supply needing maintenance. Moreover, although water rights can be transferred between users, this transfer must still ensure that the rights are maintained in a productive state, tying back into the notion of beneficial use and the potential for forfeiture if not upheld.