The River Basin Model places an emphasis on 'River' as it leads one to believe that the model is primarily concerned with water management. The emphasis should be placed on 'River Basin,' and that term should be interpreted in its broadest sense as meaning a geographic area of land. Through its two major components--in this report, human interaction and computer simulation--the model represents the economic, social and governmental activity that takes place within the geographical boundaries defined by a river basin. The model is unlike most other simulation or human interaction models. It was not designed to accomplish any one specific purpose. Rather it was designed to let its users represent the major economic, social, and governmental decision-making processes which cause a regional system to function and change on a year-to-year basis.