Quantifying Household Water Use and Its Determinants in Low-Income, Water-Scarce Households in Karachi

Water system investments in megacities in South Asia are driven by a perceived 'shortage' of water supply compared to water demand. However, water demand estimates for such cities often do not reflect local socioeconomic and demographic characteristics nor account for seasonal variability. In this study, using a mixed-methods approach, we quantify household water use and its determinants and assess the seasonality of access to piped water in the low-income, water-scarce township of Lyari in Karachi. Results from over 600 household surveys show that the reported per capita water usage at the household level is lower than the assumed water demand by the city's water utility. Water use is found to differ by gender, season, and economic status. More affluent households are able to "purchase" water security and sustain higher water use even in situations of extreme water scarcity. The perceived sufficiency of water supply improves markedly in the winter despite no increase in supply, indicating reduced demand. These findings can inform more accurate water demand projections for Karachi and highlight the importance of accounting for local socioeconomic and environmental contexts in water demand projections.