Just over four decades ago, the California Supreme Court fused the state’s emerging public trust doctrine with its intricate water rights system in the watershed Mono Lake decision. Perhaps most notably, the ruling allowed for the reevaluation and reduction of older water rights to protect public instream water uses. The decision rippled throughout other Western states, and scholars continue to grapple with its implications for water rights. Through a state-by-state review, this Article explores the diverse state responses to the public trust doctrine.
We draw several conclusions based on our analysis. First, this remains a tremendously active area of legal development; the trust is not a historical artifact. Second, states show significant variation in the way that the public trust relates to water law, and the path a state might take is very difficult to predict based on precedent. Third, because of this difficulty, federal courts should certify public trust questions to state courts to allow state courts to determine, in the first instance, what the public trust requires in that state. Fourth, the doctrine continues to play a significant role in preventing ossification of water law by invigorating the common law and providing flexibility for water reallocation by the state; this flexibility is likely to become ever more significant in light of climate change and changing social goals. Finally, we note an emerging convergent legal evolution toward the protection of public trust uses, although states use diverse mechanisms to achieve that goal.
This overdue review provides valuable context for practitioners, scholars, and jurists wrestling with the integration of the public trust and water rights. The article sets the stage for the next forty years of water law evolution in the West.
