Forecasts and the Role of Alternative Futures

A review of previous water resource forecasts by the Kerr Commission, the Water Resources Council, and the USGS is presented. Comparison among them indicate widely ranging figures depending on the underlying assumptions. Various factors affecting forecasts are presented along with conceptual problems in forecasting. Rarely have the impacts of alternative policy assumptions, life styles, or technological change been fully considered. Furthermore, forecasts are typically viewed as requirements rather than as desires which must be examined for their benefits and costs. Developing a single most likely forecast is rejected in favor of separate alternative futures. Typical assumptions for various alternative futures are presented encompassing population growth and distribution, food and fiber production, income distribution, national economic efficiency, lifestyle changes, and various means of developing, using, and conserving water resources.