In Nigeria, municipal water systems are crucial for public health but often suffer from underinvestment and mismanagement. A difference-in-differences model will be employed to assess clinical outcomes before and after interventions in selected communities, with data collection from to . The analysis revealed significant reductions (p < 0.05) in waterborne diseases among participants exposed to improved municipal water systems compared to controls. The difference-in-differences model effectively captured the impact of municipal water system improvements on clinical health outcomes, providing a robust method for future evaluations. Future studies should consider expanding the scope and duration of interventions in underprivileged areas. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.