Leakage Rate Uncertainty in Water Distribution Systems with Uncertain Demands: Impacts on Delivery Pressures

Leakage rate has long been known to be related to the internal pressure of the pipe at leak locations. Reducing leakage and excess pressures are two main goals in pressure management activities. Computer model-based leak detection methods that detect leaks by analyzing the pipeline hydraulic state have been widely employed in the industry, but their effectiveness in practical applications is often challenged by real-world uncertainties. This study quantitatively assessed the effects of uncertainties in leakage rates, consumer water demands, and pipes roughness on the delivery pressures in water distribution systems. Variations in leakage rates due to changes in pressure and discharge coefficient are shown. And, the most sensitive uncertain parameters contributing to uncertainty in leakage rates are determined. For this purpose, the mean-centered first-order method is used to estimate the first and second moments (i.e., mean and variance) of leaks. Then, changes in delivery pressures caused by uncertainties in leakage rates, consumer water demands, and pipes roughness are quantified using Monte Carlo simulations. This study provides valuable quantitative results contributing toward a better understanding of how real-world uncertainties affect pressure distributions in water distribution systems and can be helpful in pressure management studies.