Regional Multivariate Indices of Water Use Potential for the Continental United States

The necessity of freshwater for sustaining human life has prompted the development of numerous estimation techniques and metrics for understanding where, when, and why water is used. While estimates are valuable, techniques for estimating water use vary, and may be difficult to replicate and/or unavailable on an annual basis or at the regional scale. To address these drawbacks, this paper proposes a series of regional indices for the continental United States that could serve as proxies for water use that are based on key variables associated with water use. Regional indices at the county level are computed, compared against each other, and compared to water withdrawal estimates from the United States Geological Survey (USGS). These comparisons highlight differences amongst the derived indices and the water withdrawal estimates. They also demonstrate promise for future development and implementation of related indices, given their similarities with water withdrawal estimates. Using only a small set of variables, these indices achieve some degree of similarity (~20%) to estimates of water withdrawals. The comparative data availability and ease of estimating these indices, as well as the ability to decompose the additive indices into their constituent use categories and constituent variables, renders them practically useful to water managers and other decision makers for identification of locally specific drivers of water use and implementation of more geographically-appropriate policies to manage scarce water resources.