Assessing trends in urban municipal water use across the Great Lakes Basin

Municipal water use has been decreasing in the Great Lakes region since the 1970s, though the driving forces behind this decline are not clear. We analyzed this trend by calculating and comparing residential per capita water use across select cities to five socioeconomic factors. Our findings reinforced previous research by indicating that water use, and residential water use in particular, has been decreasing across all five municipalities in our study. We also find the percentage of white residents served by a municipal water supplier to be positively associated with per capita water use, while income inequality is negatively associated with per capita water use. We find per capita water use to be strongly associated with service area population. Water use shifts coincided with abrupt changes in water supply service areas in two of the five cities in our study, underscoring the significance of the rationale for differentiating total water pumped to a distribution system from per capita metered residential use. Our findings have important implications for the economy, the citizens, and the ecosystems of the Great Lakes. They further dovetail with a vision for water use policies guided not just by trends in metered water use, but also by historical and projected changes in the demographics of water users. The relationships observed in our study may help guide water use policies by addressing current and potential future inequities in water distribution and water affordability, and improving understanding of relationships between trends in consumptive use and the regional water balance.