Water treatment facilities in Ethiopia are crucial for public health but often operate inefficiently. Panel data analysis was employed to assess the performance of water treatment facilities, utilising a specific econometric model. The analysis revealed significant improvements in operational efficiency across selected facilities (e.g., by up to 20% reduction in energy consumption). Efficiency gains were quantified and can be attributed to improved management practices and technological upgrades. Further implementation of best practices and investment in maintenance are recommended for sustained efficiency improvements. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.