Nowadays, the rapid growth of operational costs and human resource shortages increase the importance of the leakage reduction, and the pressure management. This paper presents an optimisation procedure placing pressure-reducing valves (PRVs) to minimise the water losses of real-life water distribution networks (WDNs). The number and placement of the valves are optimised from clustering perspective with the Leiden algorithm. The optimal settings of the valves are determined with a differential evolution algorithm, where a compound fitness function is applied. On the one hand, it minimises the leakages, on the other hand, evades the pressure-dependent consumer outages, i.e. it keeps the pressure above the desired. Seven real-life water distribution networks were analysed from the region of Western Hungary using the techniques. Moreover, three of them are analysed in details. The robustness of the achieved leakage reduction with the optimised PRV placement is analysed to the uncertainty of the leakage exponent.