Embodiments of the present invention relate to water leakage detection. Data obtained by a smart electricity meter during a predefined time period is collected, where the smart electricity meter is associated with a water-consuming unit. Usages of certain electric appliances in the water-consuming unit during the predefined time period are determined based on the collected data. The electricity consumption of those appliances is correlated to water consumption. The legitimate water consumption of the water-consuming unit during the predefined time period is then determined based on the usages of the electric appliances.