This paper studies the regional consumption of household water in Spain in the period 2000–2018. The use of the methodology proposed by Phillips and Sul allows us to conclude that there is no single pattern of behavior across the Spanish regions. By contrast, we can determine the existence of three convergence clubs, confirming serious regional disparities in water consumption. Navarra, País Vasco, La Rioja, and Cataluña are included in the convergence club that shows the lowest levels of household water consumption, while the Islas Canarias, Comunidad Valenciana, Castilla y León and Cantabria belong to that with the highest consumption. The determinants of the forces that drive these convergence clubs are difficult to identify because the demographic, economic and structural variables of the network interact in different ways. Nevertheless, we can select a group of explanatory variables that help to explain the formation of the convergence clubs. These are regional household income, the birth rate in the regions, and the regional spending on environmental protection. Increments in the levels of these variables are helpful for reducing household water consumption.