The flavour profile analysis (FPA) panel of Aigües de Barcelona has participated in three engineering projects initiated to improve both the quality of the water supplied and the use of the scarce resources available. The information provided by the panel enables a solid evaluation of the organoleptic quality of the water produced in the facilities, which is very useful in making decisions concerning the development of the projects. The first project refers to the Besòs full scale nanofiltration pilot plant. The study includes characterisation of the organoleptic quality of the water obtained and the behaviour of blends in different proportions with water from the Ter river. Secondly, this article presents the results obtained in El Papiol pilot plant for the reduction of trihalomethanes in water from the Abrera WTP, situated by the Llobregat river. The tasting results indicate that the stripping treatment slightly improves the quality of water, whereas the improvement is more remarkable with carbon filtration. The third project was the reverse osmosis pilot plant installed in the Sant Joan Despí WTP, which also collects water from the Llobregat river. A gradual improvement of the water treated was clearly observed when increasing amounts of reverse osmosis treated water were added. Some trends were also observed according to the characteristics of the feed water to the reverse osmosis facilities.