"Water leaks are a concern for Kosovo's utilities, costing the nation €30 million annually. This thesis compares the costs and benefits of four leakage reduction methods in the Hidrodrini utility, Kosovo, to determine which one is the most cost-effective. These methods are: (1) installing district metering areas (DMAs), (2) increasing leak-detection personnel, (3) installing pressure-reducing valves (PRVs) in existing DMAs, and (4) replacing aging pipelines. The results show that DMAs provide the greatest net present value (NPV), followed by increasing leak-detection personnel. PRVs and pipe replacements both exhibit negative NPVs, suggesting that these methods may be more costly to implement and provide fewer benefits in return. One-way sensitivity analysis of all methods showed that different values of the main assumptions did not change the order of most-to-least cost-effective strategies, although they slightly changed NPV values. "