Author(s)

P.F. RICCI

Abstract

The purpose of this paper is to develop, from a very wide variety of public data, a synthesis of the status of water supply, demand, and quality for the United States from 1985 to the present, in an effort to obtain a dynamic baseline for assessing the sustainability of multiple water uses. Although the United States has relatively ample supplies of water, it is likely that deficits will occur in areas with increasing population and economic development. Variations in population, industrial, and agricultural production are driven by internal and external factors among which water probably causes the largest disruptions because of the inability to adapt to those changes. Climate changes due to global and regional warming trends also have major impacts on water availability and quality, although they are less sudden than structural changes in the economy. To help frame a baseline from which those changes can be measured to assess its sustainability for the population of the United States, we summarize the most salient findings about the status of US water supply, demand, and quality at the level of the water resource regions, and states over a period of approximately 20 years. Our synthesis of the data collected by the US agencies indicates that water quality is improving and the supply of water for the United States is generally good. However, shortages of water predicted from linear extrapolations of past trends, appear principally to affect the western water resource regions. Using US Census Bureau ‘high population’ forecasts, water shortages may be felt earlier and in more water resource regions than previously expected. These conclusions implicitly take into account changes in the US economy during the mid-eighties but do not account for: regional-scale climate, legal low-flow requirements, or other non-routine occurrences.

Keywords

demand, supply, sustainability, water quality, water quality index, water uses