Unpredictability of Intermittent Water Supply and Associations with Child Health in Urban India

Abstract Unpredictable water delivery within intermittent water supplies (IWS) may pose critical but underrecognized health risks. Using longitudinal data from nearly 2000 households with IWS in Hubli-Dharwad, India, we evaluated associations between water delivery unpredictability and caregiver-reported diarrhea in children <5 years. In adjusted mixed-effects models, children had 47% higher odds of diarrhea if water delivery deviated from the expected day (odds ratio [OR]=1.47, 1.25–1.74) but not if it deviated from the expected hour (OR=1.09, 0.90–1.32), compared to predictable IWS (delivered as expected). The influence of unpredictability was pronounced among households with infrequent supply. In contrast, children with predictable IWS had similar diarrhea prevalence as those with continuous water supply (OR=0.89, 0.71-1.12). Our findings demonstrate that water delivery unpredictability, especially delays of days, is a key determinant of health outcomes. Improving delivery schedule reliability could offer an immediate, low-cost pathway to reduce disease burdens in settings with IWS.