Water Resource Systems Models: Their Role in Planning

Abstract

Planning is an integral part of water resources development and management. Whether or not particular plans or programs are eventually implemented, the planning process itself forces us to think about what we are or should be doing to address a particular set of problems or needs. The planning process should lead to a better understanding of what will happen if we do or do not act and, if we decide to do something, which of many possible actions is likely to be the best. Such planning requires information. Models are an increasingly important source of information, but such information is never complete, is rarely if ever certain, and hence is never a substitute for the judgment of experienced planners and managers. This paper attempts to reflect on the broader context in which models are used in the practice of planning, the inherent limitations of models in this broader context, and hence the challenges modelers have when addressing the information needs of planners and managers. Some criteria for judging the degree to which models have met these needs are reviewed. The paper concludes with some thoughts on the current state of planning models and supporting technology.