This study examines the reliability of municipal water systems in Tanzania by applying a quasi-experimental design to analyse data collected from to . A quasi-experimental design was employed, including regression discontinuity analysis (RD), to assess the impact of various interventions on water system reliability. Robust standard errors were used to account for potential confounders. Regression discontinuity analysis revealed that proximity to urban centers significantly influenced water supply reliability, with a statistically significant difference in reliability scores between areas within 1 km and more than 5 km from urban areas (p < 0.05). The quasi-experimental design provided robust insights into the factors affecting municipal water system reliability. Interventions focusing on improving infrastructure in peri-urban regions are recommended to enhance overall system reliability. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.