Science and Decision Making for Water Resources

Many water-resource controversies are couched in scientific terms, although often they are not scientific disputes. Scientific information can help resolve such issues when it sheds light on the likely effects and effectiveness of policy options, but sometimes even the best scientific information is not relevant to the basic issues in dispute. I discuss several controversial topics recently studied by the National Research Council, including the Mono basin ecosystem, wetlands delineation, anadromous salmon in the northwestern United States, and the science underlying the Endangered Species Act. In each case, the controversies had scientific and nonscientific aspects. Clarifying the science helped decision making in some cases but never provided a complete resolution of the problem. Common barriers to resolving the controversies included varying policy goals among the parties, mutual mistrust, the amount of money and time needed to solve the problem, the lack of a coherent management authority or multiple jurisdictions, scientific uncertainties, and the nonscientific nature of the issues in dispute. Science is only a part of the solution to water-resource problems, although it is an essential part. Decisions to protect endangered species, to protect wetlands, or to maintain Mono Lake at a particular level are policy decisions. Those policy decisions are sometimes mistaken for scientific issues. Much of resource management lies outside science, involving economics, values, politics, and other factors. Scientists can and should ensure that science is understood and not misrepresented. It is often appropriate for decision makers to weigh other factors as heavily as science, but never to claim scientific support for a decision when there is none. To be most likely to influence actions, science should be clear and reliable when that is possible. It is essential that participants' goals and values be made explicit and that scientific arguments not be used as surrogates for the goals and values that are really in dispute.