As multiobjective evaluation of water resource investments becomes more common, it is important to develop conceptual bases for including monetary as well as nonmonetary impacts in the evaluation process. This is currently hampered by the lack of a comprehensive and systematic model which permits the identification and display of the many project impacts. And, more importantly, there is little information on the linkage between economic activity and many environmental impacts. A start is made by depicting natural resource use by sector of economic activity, with concentration on land use. A simulation model is developed which will determine acres in certain land-use categories in Southern Idaho over time without any water development. By being able to predict land use changes with and without a project, the first step in linking economic activity to certain environmental impacts has been taken. (Author)