Non-Revenue Water in Flanders

On 19 October, Vlakwa, together with AquaFlanders and the Flemish Environment Agency organised a meeting on Non-revenue water reduction. There was a morning programme of presentations on the various aspects of NRW and an afternoon programme of pitches on all kinds of innovations that should help to reduce leakage losses in particular.

To my regret, due to a delayed train, I missed the presentation on the Blue Deal in the morning programme; during the coffee break, a helpful participant brought me up to speed. The bottom line is that the dry summers of the past few years have led to a programme from the Flemish government to tackle the drought problem in the region in a structural way (see for more information). Within that framework, activities to reduce leakage losses and NRW in general fit very well. The two presentations after my entry, on an interpretation of the NRW problem and on innovations to combat it, both gave a good overview. These were followed by a presentation on the internationally widely applied approach of ILI and UARL (infrastructure leakage index and unavoidable annual real losses) by the spiritual father of these concepts, Allan Lambert. This speaker emphasised that the ILI indicator is much more suitable for comparing the NRW performance of different water companies and countries than the commonly used leakage loss or NRW percentage. Nevertheless, in the ensuing panel discussion on practices and developments, it appeared that many companies have made their own choice in this respect and that ILI is certainly not yet the gold standard in Flanders and the Netherlands. One reason for this is that although this indicator is technically correct and usable, it is difficult to communicate with citizens. The inefficiency of use of water resources indicator was mentioned as a possible more suitable alternative (not known to me). An interesting discussion ensued about the observation that solving the NRW problem in Flanders only contributes to a limited extent to solving the drought problem, but that it is nevertheless important to fight NRW, because it is one of the most visible modes of water loss.

The afternoon part of the meeting was filled with an Ecosystem Partnership workshop and a tour of various innovation providers, each pitching their solution to a successive groups of participants. As I was one of the pitchers, I unfortunately could not participate in the workshop. I told the visitors about our institute KWR, about our approach to leak detection and localisation (applying several methods in parallel to cover the weak spots of one with the other), but especially about how we use our optimisation platform Gondwana ( to help water companies decide how many sensors (pressure, flow) they need to create a measurement network or DMA layout for leak detection and where they can best be placed. And about the very successful collaboration with Dunea and Brabant Water and the great results we have achieved together. In two presentations in the morning, it was indicated that making a good DMA layout is considered one of the important challenges, for which we as KWR can propose a solution. Because the participants were led along all the pitches in small groups, and because the limited size of the groups made it easy to ask questions, a good balance was achieved between reach and interaction. A pleasant way of presenting.

All in all, this was an instructive meeting with plenty of opportunity to make interesting new contacts. Nice initiative of Vlakwa, AquaFlanders and the Flemish Environment Agency!