Introducing pressure and number of connections into water loss indicators for French drinking water supply networks

In France, the system of performance indicators defined within the relevant regulations does not include indicators relating to pressure, or the number of connections. So, Irstea and Veolia Water decided to create a new system of water loss indicators designed for use in France and that would take into account these parameters. The study was initially carried out at District Metered Area (DMA) level. These analyses showed the advantages of considering the ratio of losses to number of connections, but did not highlight a significant link between water loss levels and average pressure. After that, using a module that automatically calculates average pressure based on an EPAnet model of a network, it was possible to carry out a study at the system level. The results at the system scale were similar to those obtained at the DMA level. The study demonstrates that it is relevant to use a performance indicator of losses per connection. On the other hand, it showed no link between the volume of losses and the average pressure, which is contrary to what is commonly admitted.