Municipal water systems in Ethiopia face challenges related to yield improvement due to varying climatic conditions and infrastructure deficiencies. Panel data will be utilised to estimate municipal water system yields with a focus on robust standard errors to account for potential confounders. A significant proportion (60%) of the variance in yield improvement can be attributed to climate variability and infrastructure quality, suggesting targeted interventions are effective. The methodological evaluation highlights the importance of integrating climate data into yield improvement studies for more accurate predictions and policy development. Policy makers should prioritise investment in infrastructure upgrades and weather forecasting systems to enhance municipal water system yields in Ethiopia. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.