Municipal water distribution leaks are a tremendous infrastructure challenge for Water Utility Companies (WUC) across the globe. Picture this, today 55% of the world’s population lives in urban areas, a proportion that is expected to increase to 68% by 2050. Projections show that urbanization, the gradual shift in residence of the human population from rural to urban areas combined with the overall growth of the world’s population could add another 2.5 billion people to urban areas by 2050. Therefore, many of the economic and property damage costs associated with pipeline leaks and breaks are rapidly rising at an alarming rate and becoming one of the main causes for loss of revenue in the water industry. 
Water losses not only deprive Water Utility Companies (WUC) from needed revenue and paralyzed their effort to provide quality service, but should also become a sensitive topic due to “Day Zeros” across the world, terminology coined to express when a city no longer has running water for its citizens.
The overall impairment caused by leaks depends on the time window between detection and its isolation, which depending on the utility can last for months, even years. For many WUC the main reason why these tasks are complicated is due to the lack of active leak detection and monitoring systems, so the presence of water leaks are identified when it becomes visible at the surface level, when consequences are both harmful and expensive – too late.
Due to these challenges progressive water utilities are actively searching for innovative approaches to early detection and classification methods of leaks.
Virtual District Metered Areas (vDMA)
As we previously discussed in our blog, the practice of dividing the distribution network into sectors called District Metered Areas (DMA) is becoming synonymous with good Non-revenue Water management, however there are limitations such as high implementation cost, adverse effects on the hydraulic systems (less robust under failure conditions), and water quality (the configuration of strict boundaries and dead ends can create the possibility of taste and odor problems in water due to stagnation).
Digitization is transforming the landscape of available technologies for the water space and transforming the way utilities identify, alert and prevent leakages. Instead of setting up physical hydraulic control, a Virtual District Metered Area (vDMA) (see Fig. 1) maintains more flexibility because it does not require any physical closing valves and pipeline isolation. In contrast to the traditional DMA, multi-parameter sensors are installed in key positions to create “virtual DMA zones”. These sensors can simultaneously measure bidirectional flow, pressure and volume of consumption, record the data and have the capability to communicate and synchronize with analytical software that will map out the state of the network. The dimension of the area depends on the complexity of the hydraulic system, the number of installed sensors and the accuracy of the sensors. 
Fig 1 – Visual map of the distribution network in a virtual cluster and identified by optimal boundary locations. Source: Stor Water Collection (2021)
Setting up and Monitoring a vDMA
After the strategic positioning of flow meters and/or pressure loggers in the network, the basic methodology of monitoring a virtual DMA is to continuously measure the flow rate (velocity) at these points and compare the metered data with reference values or data from hydraulic models. Analysis of the influenced meter spread over the distribution system results in a first rough estimation of the localization of the possible leaks 
Industry standard minimum night flow analysis and water balance, combined with statistical machine learning models for pattern recognition and historical data, can then create recognizable signatures of different types and scale of leaks throughout the water distribution pipeline network (see Fig 2), aiding in the task of early leaks detection and monitoring.
Fig 2 – Location of a leak in a vDMA. Source: Stor Water Collection (2021)
vDMA approach and strategy
Quasi-real-time monitoring of the water network means that utility operators can proactively respond and allocate resources more efficiently, pivoting resources to develop better assessment strategies. By having a bird-eye view of the network, utilities can not only avoid service disruptions, but also change the economics of water management, requiring less manpower to address future problems.
 United Nations, Department of Economic and Social Affairs, Population Division (2019). World Urbanization Prospects: The 2018 Revision (ST/ESA/SER.A/420). New York: United Nations.
 Mamo T, Juran I, Shahrour I (2013), Virtual DMA Municipal Water Supply Pipeline Leak Detection and Classification Using Advance Pattern Recognizer Multi-Class SVM
 Gangl, G., Kober, E. and Fischer J. (2012), Virtual DMA – a practical example for sustainable water loss reduction. blue facts, 2012, 102–108.