Conceptual models for water resource planning

Three similar models for the water resource planning in an urban area are compared. The first is static [1], but permits the examination of the political processes surrounding water resource decisions. The second could be dynamic [2], but its principal orientation is towards the examination of nonquantifiable social and environmental indicators. The third is developed here is somewhat more detail; it is dynamic, permits the examination of political alternatives but not their embedding in the model, and allows an indirect analysis of the questions raised by the first two models. Explanations for system behavior are found in the language of feedback loops, and system behavior is displayed graphically. This model encompasses the water quality, its cost, and their effects on and by the lifestyle of the city's populace.