Recent studies have explored the impact of municipal water systems on South Africa's economy and environment, but methodological consistency remains a concern. The study employs DiD regression analysis with robust standard errors to compare pre- and post-intervention outcomes for a sample of municipalities, accounting for potential confounders. A significant difference-in-differences effect was observed in the cost-effectiveness metrics (p < 0.05), indicating that implementing water management strategies reduced costs by approximately 12% over two years. The DiD model provided robust evidence for the cost-saving benefits of municipal water system improvements, with results corroborating previous findings but offering enhanced statistical rigor. Future studies should consider expanding the sample size and including additional control variables to further validate these findings. Model estimation used $\hat{\theta}=argmin_{\theta}\sum_i\ell(y_i,f_\theta(x_i))+\lambda\lVert\theta\rVert_2^2$, with performance evaluated using out-of-sample error.