following National Audubon Society v. Superior Court (1983), it does impose a condition on the future use of waters appropriated to further the public interest (the finding that harm must be minimized to the extent feasible). There are, however, broad discretionary powers for states and legislatures to define exactly what the public purpose is. As technology has advanced, waters of the U.S. have been used less for commerce and navigation, the basis for most current environmental law, and more for recreational purposes. In recognition of this, the public trust doctrine can also be employed, using the discretionary powers enjoyed by states for determining public purpose, as the basis for the preservation of a public interest in recreation. Other states, such as Montana, have integrated natural resource values and the public trust doctrine into appropriative water rights through allowing water to be appropriated for future uses that are protective of the environment or a resource (such as maintaining instream flows for water quality or habitat connectivity). In this way, states may establish an appropriative right for water that is integrated with the system of water law as the water is not "used" in the traditional sense of being diverted for commercial, agricultural, or industrial use, but is appropriated to remain in the stream channel. The overriding legal implication of the courts decision in National Audubon Society v. Superior Court (1983) is that traditional use of the public trust doctrine to ensure that valuable public resources are not lost to the public through diversion to public control has been altered to encompass an all-embracing environmental protection mechanism. In cases in which the traditional doctrine evolved to protect common rights of access for commercial purposes, the modern public trust doctrine proclaims conservationist principles. See also Mono Lake Los Angeles Department of Water and Power California Water Wars References External links United States environmental case law United States statutory interpretation case law United States energy case law 1983 in the environment 1983 in United States case law National Audubon Society California state case law 1983 in California Los Angeles Aqueduct United States water case law