33 Cal. 3d 419 (Cal. 1983); 658 P.2d 709; 189 Cal. Rptr. 346
National Audubon Society v. Superior Court—widely known as the Mono Lake case—is a foundational decision in American water law and environmental law.
Does the public trust doctrine impose a continuing duty on the State of California to protect Mono Lake's navigable waters and related public values by reconsidering and, if necessary, modifying previously granted appropriative water rights to tributary streams—and do the courts have jurisdiction, alongside the State Water Resources Resources Control Board, to adjudicate such claims?
In California, the state holds navigable waterways in trust for the benefit of the public. The public trust doctrine protects traditional trust uses such as navigation, commerce, and fishing, and—consistent with Marks v. Whitney—also encompasses ecological, recreational, and scenic values. The doctrine applies not only to direct uses of navigable waters but also to diversions from nonnavigable tributaries that affect the public trust in those navigable waters. The state has an affirmative, ongoing duty to consider, protect, and, where feasible, restore trust resources. All water rights—riparian or appropriative, old or new—are subject to this inherent limitation and to the state's continuing supervisory power; prior administrative approvals do not irrevocably alienate trust obligations. Courts and the State Water Resources Control Board have concurrent roles: the Board has primary expertise in water allocation, but courts retain jurisdiction to enforce the public trust and review or supplement administrative action. Relief may include reconsideration, conditioning, or reduction of diversions to prevent unnecessary harm to trust uses, with the state required to balance competing interests to protect the trust to the extent feasible.
Yes. The public trust doctrine applies to Mono Lake and to diversions from its tributary streams that harm trust resources, and it imposes a continuing duty on the state to protect public trust uses. Previously granted water rights may be reconsidered and modified to mitigate or prevent unnecessary injury to the trust. The courts share concurrent jurisdiction with the State Water Resources Control Board; the superior court erred in effectively declining to adjudicate the public trust claims. The Supreme Court directed that the case proceed consistent with the doctrine, with appropriate deference to the Board's primary expertise in water allocation and continued judicial oversight.
National Audubon is a cornerstone of public trust and water law. It integrates the common-law public trust doctrine with California's statutory water rights system, making clear that vested appropriative rights remain subject to continuing state oversight to protect navigable waters and associated ecological and recreational values. The case extends the trust to cover effects from nonnavigable tributaries, articulates a balancing framework that prioritizes feasible protection of trust resources, and clarifies concurrent judicial and administrative authority. For law students, it exemplifies the interplay of common law, statutory schemes, administrative law (primary jurisdiction and judicial review), property limits (inherent constraints on water rights), and environmental values in resource allocation. Practically, the decision catalyzed administrative reconsideration of Mono Lake diversions and influenced water management across California, culminating in later Board decisions that raised Mono Lake's target levels and conditioned LADWP's diversions. Its reasoning has been cited nationally as states and courts grapple with reconciling historic consumptive uses with modern environmental and recreational needs.