Which doctrine determines water rights based on the priority of beneficial use?

The correct answer focuses on the prior appropriation doctrine, which is a legal principle governing water rights, particularly in the western United States. This doctrine operates on the premise of "first in time, first in right," meaning that the individual who first puts a water resource to beneficial use has the superior claim to that water. This method of determining rights is essential in arid regions where water is scarce, allowing users who have a prior beneficial use to secure their right to continue using that water even if it may affect more junior claims.

In practical terms, under the prior appropriation doctrine, a person can divert water from a source, such as a river or stream, as long as they follow the legal processes for appropriating and using it beneficially. The first user gains priority, which remains intact as long as they continue the beneficial use of the resource.

This doctrine contrasts with other approaches to water rights, such as the riparian doctrine, which is primarily concerned with land ownership adjacent to a water body and is not based on the priority of use. The rule of capture relates mainly to oil and gas rights rather than water rights, and the subsurface rights doctrine pertains to underground resources, distinguishing it further from those that govern surface water rights. Understanding