Residential and Non-residential Minimum Night Consumption Analysis Based on Smart-meter Data

Accurate estimation of users’ minimum night consumption (MNC) is essential for effective leakage assessment in water distribution networks using the Minimum Night Flow (MNF) method, based on which leakages are quantified by subtracting users’ consumption from the network nighttime inflow. However, the limited availability of MNC data—often scarce and mostly tied to local contexts—can lead to misestimations of leakage rates. This study contributes to the literature on MNC assessment by analysing hourly water-consumption data from about 1,700 residential and non-residential users in three Italian districts, with the aim of investigating the related MNC values and distributions. Results indicate that residential MNC values range between approximately 1.3 and 2.5 L/user/h, with increasing values likely due to irrigation of private gardens. Conversely, non-residential MNC values are higher and more spread, ranging from about 3.3 to 7.1 L/user/h, reflecting heterogeneous water-consumption patterns including a few highly demanding activities operating overnight. Overall, the study findings can contribute to more accurate leakage assessment, and reveal the need for targeted monitoring, particularly for non-residential users.