Nigeria has implemented regional monitoring networks to assess water quality across its diverse geographical regions. However, there is a need for methodological evaluation of these systems to ensure they are reliable and effective in providing consistent data. The review employs rigorous methodology, including a comprehensive search strategy across relevant databases, critical appraisal of studies using predefined criteria, and statistical analysis focused on robustness of Bayesian hierarchical models. Bayesian hierarchical models have shown moderate reliability in measuring system performance across different geographical regions, with some networks demonstrating consistent results within the expected uncertainty limits (95% confidence interval). The findings suggest that while there is room for improvement, Bayesian hierarchical models are a viable method for evaluating reliability of Nigeria's regional monitoring networks. Further studies should be conducted to enhance model robustness and ensure consistent performance across diverse environmental conditions. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.