Experiences from a large-scale implementation of digital water meters used for improved leakage management

Similar to other infrastructure sectors, the water distribution network is also undergoing increasing digitalisation, including real-time measurement of current system statuses. While high-resolution data is frequently available at the main points of the networks, the main challenge lies in remotely obtaining high-resolution water consumption data. Water meters are usually installed at remote and underground locations without a connection to the power grid, requiring battery-powered devices and reliable and energy-efficient wireless communication technologies. For an efficient large-scale implementation, documented practical experiences in real world applications are rare. In this work, the experiences gained of a large-scale implementation of digital water meters in a demonstration project are presented. The case study includes 163 customer sites with the majority of single-family houses, aiming to measure water consumption data at a temporal resolution of 15min in near real-time. In contrast to the electricity sector, there is no EU-wide legal regulation for the installation of digital meters. Instead, the requirements are depending on the specifications of the digital water meter type and are subject to the European General Data Protection Regulation (GDPR) at the intended spatial and temporal resolution, as detailed information about the user behaviour can be revealed. Subsequently, active costumer agreement was obtained in form of a signed declaration of consent and the approval rate was significantly increased through a pro-active approach of the network operator (e.g., detailed and personal information about the project). In total, around 70% of households were equipped with a commercially available digital water meter, using mioty for the remote read-out. Initially facing data gap problems, after comprehensive software updates and improved antenna positions, the quality of service (as the ratio between received data packages and theoretically expected measurement data) still varies between 10 and 100% depending on the installation site, but during the last month of operation, 84% of the meters transmitted at least 75% of the expected data. In combination with inflow and pressure measurement data, the measured water consumption data is afterwards used for an early warning system designed for detecting new leakages, serving as an exemplary application for digital water meters. The leakage detection and leakage localisation are implemented as data-based and model-based approach, respectively, and the system was tested on ten engineered leakage events with leakage sizes between 0.1 and 2.0l/s. Despite a temporal failure in the data communication, strong fluctuations in the pressure data, and changing operating conditions, even small leakages could be timely detected, and the possible leakage area could be successfully narrowed down to 10 to 40% of the network length for the subsequent on-site fine search.