National Audubon Society v. Superior Court
Supreme Court of California
658 P.2d 709 (1983)
Since 1940, the Los Angeles Department of Water and Power (DWP) had diverted freshwater from four of the five streams feeding Mono Lake, a saltwater lake supporting a large shrimp population and bird-nesting islands, causing the lake's water level to drop, a third of its surface to dry up entirely, and one island to become a peninsula accessible to land predators, forcing nesting birds to abandon it. The National Audubon Society (plaintiff) sued to enjoin further diversion, arguing the lake, islands, and shores were protected by the public trust doctrine; the trial court granted DWP summary judgment, holding the doctrine provided no independent basis for an injunction, and Audubon petitioned the California Supreme Court for a writ of mandate.
Whether the public trust doctrine preserves the state's sovereign authority to protect public trust uses, thereby preventing owners from acquiring a vested right that would allow them to harm the land.