Although there are multiple causes of the water scarcity crisis in the American Southwest, it can be used as a model of the long-term problem of freshwater shortages that climate change will exacerbate. We examine the water-supply crisis for 22 cities in the extended Southwest of the United States and develop a unique, new measure of water conservation policies and programs. Convergent qualitative and quantitative analyses suggest that political conflicts play an important role in the transition of water-supply regimes toward higher levels of demandreduction policies and programs. Qualitative analysis using institutional theory identifies the interaction of four types of motivating logics-development, rural preservation, environmental, and urban consumer-and shows how demand-reduction strategies can potentially satisfy all four. Quantitative analysis of the explanatory factors for the variation in the adoption of demand-reduction policies points to the overwhelming importance of political preferences as defined by Cook's Partisan Voting Index. We suggest that approaches to water-supply choices are influenced less by direct partisan disagreements than by broad preferences for a development logic based on supply-increase strategies and discomfort with demand-reduction strategies that clash with conservative beliefs.

This article (1) discusses existing efforts to measure water conservation policies (WCPs) in the United States (U.S.); (2) suggests general methodological guidelines for creating robust water conservation indices (WCIs); (3) presents a comprehensive template for coding WCPs; (4) introduces a summary index, the Vanderbilt Water Conservation Index (VWCI), which is derived from 79 WCP observations for 197 cities for the year 2015; and (5) compares the VWCI to WCP data extracted from the 2010 American Water Works Association (AWWA) Water and Wastewater Rates survey. Existing approaches to measuring urban WCPs in U.S. cities are limited because they consider only a portion of WCPs or they are restricted geographically. The VWCI consists of a more comprehensive set of 79 observations classified as residential, commercial/industrial, billing structure, drought plan, or general. Our comparison of the VWCI and AWWA survey responses indicate reasonable agreement (ρ = 0.76) between the two WCIs for 98 cities where the data overlap. The correlation suggests the AWWA survey responses can provide fairly robust longitudinal WCP information, but we argue the measurement of WCPs is still in its infancy, and our approach suggests strategies for improving existing methods.

Urban water supply systems in the United States are increasingly stressed as economic and population growth confront limited water resources. Demand management, through conservation and improved efficiency, has long been promoted as a practical alternative to building Promethean energy-intensive water supply infrastructure. Some cities are making great progress at managing their demand, but study of conservation policies has been limited and often regionally focused. We present a hierarchical Bayesian analysis of a new measure of urban water conservation policy, the Vanderbilt Water Conservation Index, for 195 cities in 45 states in the contiguous United States. This study does not attempt to establish causal relationships but does observe that cities in states with arid climates tend to adopt more conservation measures. Within a state, cities with more Democratic-leaning voting preferences and large and rapidly growing populations tend to adopt more conservation measures. Economic factors and climatic differences between cities do not correlate with the number of measures adopted, but they do correlate with the character of the measures, with arid cities favoring mandatory conservation actions and cities in states with lower real personal income favoring rebates for voluntary actions. Understanding relationships between environmental and societal factors and cities' support for water conservation measures can help planners and policy makers identify obstacles and opportunities to increase the role of conservation and efficiency in making urban water supply systems sustainable. Plain Language SummaryAs urban water supply systems confront growing populations, growing economies, and climatic stress, water conservation measures are often more effective and economical ways to assure reliable and sustainable access to water than building ever larger supply systems. We present the first analysis of a comprehensive index of urban water conservation policies for 195 cities in the contiguous United States. We find that the number of conservation measures a city adopts correlates both with environmental and societal factors and with the characteristics both of the city itself and of the state in which it is located. Cities in drier states and cities that vote for Democratic candidates in greater numbers tend to adopt more conservation policies. By identifying characteristics associated with water conservation, these results can help planners and policy makers understand how different cities face different obstacles and opportunities for adopting conservation policies.