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The growth of tourism in the last decades has left behind a significant footprint on water resources, which is particularly evident in the regions affected by water scarcity or consistent seasonal population fluctuations. However, only limited efforts were spent in evaluating the effects of tourism on water consumption with regard to specific non-residential users such as bathing facilities. The current work aimed at providing an insight into the effects of seaside tourism on water consumption in a case study coastal area in northern Italy that is typically subjected to high tourist fluctuations throughout the year. Analyses were carried out at multiple spatiotemporal scales – from urban to user level, and from yearly to daily scale – by exploiting hourly flow data collected at the inflow points of the area and at some touristic users (i.e. nine bathing facilities and a holiday home). In addition, the impact of weather – temperature and rainfall – on water use was explored. The study revealed consistent inflow fluctuations in the area concerned based on tourism (with a ratio between the maximum and minimum monthly average inflow of about 15.7) and demonstrated that the touristic component of water inflow was considerably higher than the residential component at the height of tourist season (i.e., 176 L/s against 42 L/s). Moreover, significant variations in the water inflow due to tourism and weather were also observed on a daily scale, along with considerable water consumption fluctuations in bathing facilities.

The effectiveness of pressure-reducing valves (PRVs) for optimal pressure management of water distribution networks (WDNs) is proven, but problems and operational limitations have been highlighted by some recent experiences. In this study, we analyse the functioning of a piston-actuated pressure-reducing valve (PA-PRV) with a mechanical pilot which is subjected to low-flow regimes, a condition that is often observed in real water distribution networks. The analyses were carried out by means of laboratory tests featuring two sets of experiments, i.e., (a) by testing the behaviour of the PRV when a pre-established initial value and subsequent variation of flow rate occurs in the system and (b) by testing the PRV against a temporal series of flow rates observed at the inlet section of a real district metered area. The first set of tests showed that the PA-PRV tends not to maintain pressure at the imposed set-point and exhibits an unstable behaviour characterised by significant pressure oscillations under some flow rate conditions. The second set of laboratory tests showed that the anomalous behaviour identified in the first set of tests can occur under ordinary operational conditions of a network.

This paper analyses the propagation and mechanisms of interaction of a pressure wave in a looped water distribution network by means of laboratory and numerical tests. Transients are generated by the complete and fast closure of a valve, simulating an end-user maneuver, located at the downstream end section of a service line. The adequate length of the service line allows capturing each single pressure wave inserted into the network. The executed tests and successive analysis by means of a Lagrangian model (LM) highlight the effect of the network topology and the location of the transient generation point but in a more expeditious way with respect to the use of a complete transient model. The most excited part of the system is the one in close proximity of the end-user and then the corresponding service line. Within the network, pressure waves accumulate in the areas with the smallest diameter pipes. By means of the refined LM—which is able to capture the pressure extreme values occurring in the first phases of the transient—the vulnerability maps of the network are provided. Such maps identify the nodes subjected to the most severe pressure waves in terms of both frequency and amplitude. The exposure level to transients of each node is synthesized by the value of the vulnerability index proposed in this paper.