Thermoelectric power generation is responsible for the largest annual volume of water withdrawals in the United States although it is only a distant third after irrigation and industrial sectors in consumptive use. The substantial water withdrawals by thermoelectric power plants can have significant impacts on local surface and ground water sources, especially in arid regions. However, there are few studies of the determinants of water use in thermoelectric generation. Analysis of thermoelectric water use data in existing steam thermoelectric power plants shows that there is wide variability in unitary thermoelectric water use (in cubic decimeters per 1 kWh) within and among different types of cooling systems. Multiple‐regression models of unit thermoelectric water use were developed to identify significant determinants of unit thermoelectric water use. The high variability of unit usage rates indicates that there is a significant potential for water conservation in existing thermoelectric power plants.

In the current forecasting practice, future water requirements of a growing urban area are often represented as the product of the number of people to be served by the water system and an assumed quantity of gross per capita water use. This paper describes a forecasting approach that differs from the per capita method in two important aspects. First, it disaggregates urban water use into a large number of categories, each consisting of a relatively homogeneous group of water users. Second, it links water use in each category to factors that determine both the need for water as well as the intensity of water use. This approach is incorporated into a computerized forecasting system referred to as IWR‐MAIN. The advantages of the IWR.MAIN model over the traditional per capita method are illustrated in a case study of Anaheim, California.

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This article provides water utility managers with guidance on alternative measures of water use and how these measures, or metrics, can be most appropriately used for comparing and evaluating water efficiency. There is currently no universally perfect metric for describing water use, but several metrics are better than per capita use in terms of the available data's accuracy and informational value. Water utilities and regulators have an increasing need for meaningful performance indicators and benchmarks for measuring and comparing water use. Significant improvements in the ability of water utilities to reduce “definitional noise” in monitoring and comparing water usage rates would be achieved if the water supply industry adopted a standard set of customer types and customer classification procedures. Available water production and sales records can be used to calculate both systemwide and sector‐specific metrics of water use. For a systemwide metric, the only accurate and regularly updated measure of system size is the number of connections or customer accounts.

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