Correcting Power Leakage Equation for Improved Leakage Modeling and Detection

Fluid pressure influences leakage flow rate in water distribution pipe networks. Significant progress has been made in the use of pressure management techniques to control leakage. An empirical power equation (known as the N1 power equation) is widely used to model the pressure-leakage relationship in practice. However, recent research has shown that this equation is not able to accurately model leakage under various conditions. When estimating the N1 leakage exponent for a system, the power equation assumes that leakage is located at a point in the network that is representative of the average system pressure, which is rarely true. In addition, parameters of the power equation are not constant but vary with pressure, which is a problem especially for water distribution pipe networks where pressure varies with time, for example, due to diurnal demand variation. These factors result in significant errors when the power equation is used to model leakage in real water distribution networks. This technical note analyzes the factors that introduce errors in the power equation and proposes methods to improve its accuracy. The performance of the methods is demonstrated using a case study.