Part III examines case law reflecting this doctrinal shift and concludes that the decline of the appurtenancy requirement was the inevitable result of another key doctrine in riparian law: the reasonable use requirement, under which riparian rights are correlative and are limited only by the rights of other riparian proprietors. (39) I argue that whereas the appurtenancy doctrine relied on a fundamental limiting approach to resources, the reasonable use doctrine, as interpreted and applied by the courts, relied instead on an inherently tolerant and expansionist ethic.
(83) The California Supreme Court affirmed an injunction prohibiting the diversion and explained the extent of the defendants' entitlement under such a grant: "[It] gave [defendants] no right in the land which is adjacent to the stream, and they took by the contract no riparian rights in the waters of the stream...." (84) While the defendants might have had a contractual right that was good as against the grantor, they had no rights as against other riparian proprietors. They were, in effect, excluded from the riparian community.
(87) The court noted that the doctrine of reasonable use as between riparian proprietors did not include "'the case of an interference by a stranger, who, by any means, or for any cause, diminishes the flow of the water; for this also is wholly wrongful, and no question of the reasonableness of his action in causing the diminution can possibly arise.'" (88) The court in essence announced a per se rule against water use by nonriparians, or "strangers," under which no such use could ever be found reasonable.
The release from liability that the plaintiff had sought and received from the other riparian proprietors, and his long-accepted diversion of the water, demonstrated that his usage had survived the community's scrutiny.