Pressure control is a key issue for the reduction of water loss through leakage in municipal water distribution networks (WDNs). The paper presents a general method to calibrate the proportional controllers for the real time control (RTC) of motorized pressure valves in WDNs to reduce leakage during ordinary operation. The method is based on the comprehensive dimensionless analysis of the behavior of simplified hydraulic systems under RTC scenarios. A numerical approach was used to derive a simple regressive relationship to tune the controller on the basis of the system dimensionless variables involved in the control process. The method was validated by application to a well-known bench-test water distribution network and compared with an existing literature calibration procedure. Results show that the proposed method allows for effective controller tuning and leads to performing leakage reduction-oriented real time control of pressures.

In this paper, a novel field-oriented methodology to setup real-time control (RTC) for leakage reduction by pressure control valves in water distribution networks is presented. The paper introduces modalities to address the selection of proper RTC system architecture based on the network connectivity at the valve sites. Criteria for target node identification and RTC strategy selection in case of single-control (one valve–one target node) and multiple-control (multiple valve–one target node) architectures are developed. The impact on the control performance of controller calibration and communication protocol selection procedures, and of background noise in pressure signals is also explored. Then, developed criteria and procedures are applied to a Norwegian water distribution network in which a future field-pilot RTC system will be installed. Benefits in terms of pressure control effectiveness and water leakage reduction are evaluated by simulation under different control scenarios as a basic step...

This paper investigates the potential of unsteady flow modelling for the simulation of remote real-time control (RTC) of pressure in water distribution networks. The developed model combines the unsteady flow simulation solver with specific modules for generation of pulsed nodal demands and dynamic adjustment of pressure control valves in the network. The application to the skeletonized model of a real network highlights the improved capability of the unsteady flow simulation of RTC compared with the typical extended period simulation (EPS) models. The results show that the unsteady flow model provides sounder description of the amplitude of the pressure head variations at the controlled node. Furthermore, it enables identification of the suitable control time step to be adopted for obtaining a prompt and effective regulation. Nevertheless, EPS-based models allow consistent estimates of leakage reduction as well as proper indications for valve setting under network pressure RTC at a much smaller computational cost.

This paper describes a novel methodology to evaluate the benefits of large-scale installation of domestic Rain Water Harvesting (RWH) systems in multi-story buildings. The methodology was specifically developed for application to small settlements of the minor Mediterranean islands characterized by sharp fluctuations in precipitation and water demands between winter and summer periods. The methodology is based on the combined use of regressive models for water saving evaluation and of geospatial analysis tools for semi-automatic collection of spatial information at the building/household level. An application to the old town of Lipari (Aeolian islands) showed potential for high yearly water savings (between 30% and 50%), with return on investment in less than 15 years for about 50% of the installed RWH systems.

Moveable gates for the real-time control (RTC) of sewer systems storage capacities are usually operated by controllers which, on the basis of local water level or flow velocity measurements, calculate the regulation errors of the monitored variables, determining the necessary regulator movements to lead the flow conditions to the desired set point. In this paper the results of an investigation on the influence of proportional-integral-derivative (PID) controllers and programmable logic controllers (PLC) for the RTC of moveable sluice gates positioned into sewer systems are presented. The analysis of response time, damping and regulation errors provided information on the PID parameter calibration values and on the PLC control function performances. A comparison between the two kind of controllers has also been carried out.

This paper shows the extent to which the application of real-time control techniques can help in reducing the flows discharged from quality oriented combined sewer overflow (CSO) devices in sewer systems. To this end, a quality oriented CSO device, namely the high-crested side-weir (HCSW) with downstream gate, was taken into account for the analysis. A numerical model able to simulate routing of flows in proximity to CSO devices was specifically used to evaluate the benefits of the HCSW with downstream gate, in comparison with the more traditional low-crested side-weir (LCSW), and the coupled use of HCSWs and in-sewer mobile gates controlled in real time. The model was applied by considering four different modeling scenarios to the case study of a sewer catchment in Italy, in which real storm-water events had been recorded during previous experimental investigations. Results of the simulations prove the HCSW with downstream gate always considerably reduces CSO volumes in comparison with LCSW overf...