Definitions for "Prior appropriation"
Legal principle by which the first user of water from a stream establishes a legal right to continued use of the amount originally withdrawn. Compare riparian rights.
A theory used in some western states that the first user of water has priority rights as against later users of water from the same source.
A doctrine of water law which allocates the right to use water on a first-come, first-served basis. The doctrine was developed out of the system of administrative disposition of land grant. Disputes were settled in favor of the party with the oldest grant.