What doctrine controls water rights when states do not automatically convey water rights with property?

The correct choice is the Prior Appropriation doctrine. This doctrine governs water rights in jurisdictions where water is not automatically conveyed with property ownership. It operates under the principle that water rights are allocated based on the priority of use. This means that the first user to divert water for beneficial use has a right to continue using that water, regardless of the land they own.

The Prior Appropriation doctrine is particularly significant in arid regions where water scarcity is a critical issue and thus emphasizes the importance of water rights based on historical usage rather than land ownership. This system allows users to establish and maintain water rights even if they do not own the adjacent land, contrasting with other doctrines that tie water rights more closely to land ownership.

In contrast, the Riparian and Littoral doctrines, which pertain to water rights associated with property adjacent to flowing bodies of water (rivers and streams) and static water bodies (like lakes and ponds), respectively, do not generally apply when states do not automatically convey water rights with property. The Water Rights doctrine is a more general term and does not specifically identify the legal principles governing these rights, making it less applicable in this context.