Non-revenue water (NRW)—water that is produced but not billed due to losses or unmeasured use—represents a key area of focus for water utilities aiming to improve efficiency and reduce waste. Accurate water balance calculations and minimum night flow monitoring are among the most effective methods to identify and reduce leakage. However, the reliability of these methods is highly dependent on data quality, particularly in relation to District Metered Areas (DMAs).

In many water distribution systems, boundary valves between DMAs are occasionally opened during maintenance or operational adjustments. If these valves remain open during a water balance assessment period, it can result in unaccounted-for flow between zones, leading to inaccurate leakage estimates and misinformed operational decisions. Identifying whether a valve is open or closed—at the right time—is therefore critical to producing reliable water loss calculations.

As part of the LEAKman project—a Danish collaboration demonstrating integrated water loss management—VIDI Positioners from AVK were installed on key sectioning valves to monitor their open/closed status. The objective is to support more accurate water balance calculations and improve the overall management of non-revenue water.

The solution was implemented at HOFOR, Denmark’s largest utility, which serves around one million people in Greater Copenhagen. HOFOR’s network is divided into 65 DMAs, where the ability to accurately calculate water balance is fundamental for targeted leak detection and maintenance planning.

Three shut-off valves acting as DMA boundary valves were equipped with VIDI Positioners. These battery-powered IoT sensors continuously detect and report the valve’s position in percentages and log every operation—whether the valve is being opened, closed, or partially adjusted. The data is transmitted at regular intervals, as well as in real-time when activity occurs.

The position data is automatically integrated with HOFOR’s geographic information system (GIS), ensuring that operations and maintenance teams always have access to up-to-date valve status. The information is also fed into HOMIS, the utility’s management information system developed by LEAKman partner NIRAS. HOMIS connects with the utility’s hydraulic model, which is automatically updated based on valve operations, and it can suspend water balance calculations during periods when boundary valves are open.

The deployment of VIDI Positioners has contributed to more reliable data for NRW management at HOFOR and strengthened the digital foundation for leakage control. Key outcomes include:

• Increased accuracy in water balance calculations, as the system can confirm whether boundary valves are closed during assessment periods.

• Reduced risk of unmeasured flow between DMAs, helping to avoid misleading leakage indicators and false assumptions in night flow data.

• Improved integration with operational systems, including GIS and hydraulic modelling tools, providing staff with a better overview and enabling automated decision support.

• Enhanced knowledge sharing across teams, as valve status is continuously available to both operational and planning personnel.

By integrating real-time valve monitoring into the utility’s digital systems, the project supports more targeted, efficient, and data-driven management of water loss—contributing to HOFOR’s long-term goals for sustainable water supply.