This paper presents the energy audit of a water network, which is obtained from the energy equation in integral form, and its time integration extended over a given period (day, month, or year). The analysis allows accounting for all the energy in the system, showing that the energy balance is maintained. This balance can be used to obtain performance indicators to assess the system from the energetic point of view. From these indicators, it is possible to identify the improvement actions that will make the system more efficient. This energy audit requires a previous water balance and the mathematical model of the network, both of which are necessary to know the energy flows through the system’s boundaries.

Presented herein is a methodology for evaluation of water losses based on discrimination of the two components of uncontrolled water in a water distribution network: physical losses in mains and service connections, and the volume of water consumed but not measured by meters. The water balance calculations consider that all nonmeasured consumption is uncontrolled water and consequently an apparent loss. The methodology is applicable to an entire network or portions thereof, and presumes that real losses in certain physical states of a network are a function of pressure, while apparent losses (defined as nonmetered consumed water) are a function of consumption patterns (i.e., domestic, industrial, institutional, etc.). An extended period simulation of a water distribution network is employed to accurately determine both terms.

Disaggregating residential water end use events through the available commercial tools needs a great investment in time to manually process smart metering data. Therefore, it is extremely difficult to achieve a homogenous and sufficiently large corpus of classified single-use events capable of accurately describe residential water consumption. The main goal of the present paper is to develop an automatic tool that facilitates the disaggregation of the individual water consumptions events from the raw flow trace. The proposed disaggregation methodology is conducted through two actions that are iteratively performed: first, the use of an advanced two-step filter, whose calibration is automatically conducted by the Elitist Non-Dominated Sorting Genetic Algorithm NSGA-II; and second, a cropping algorithm based on the filtered water consumption flow traces. As a secondary goal, yet complementary to the main one, a semiautomatic massive classification process has been developed, so that the resulting single-use events can be easily categorized in the different water end uses in a household. This methodology was tested using water consumption data from two different case studies. The characteristics of the households taken as reference and their occupants were unequivocally dissimilar from each other. In addition, the monitoring equipment used to obtain the consumption flow traces had completely different technical specifications. The results obtained from the processing of the two studies show that the automatic disaggregation is both robust and accurate, and produces significant time saving compared to the standard manual analysis.

This work proposes a novel indicator (HCWI) for evaluating water consumption efficiency in hotels. The indicator is built as a relative index that compares the current water consumption with an estimated minimum achievable value. To ensure the representativeness and applicability of the index, the evaluation of this water consumption baseline considers each water consumption micro-component individually and has been simplified, so it only requires fundamental characteristics of the hotel and those that are easy to identify and quantify. A value of the HCWI equal to one indicates the best water use efficiency that can be theoretically achieved with the technology available. On the contrary, larger values of the HWCI indicate high levels of water use inefficiency by the hotel. The applicability of the indicator is tested in six different hotels located in a touristic region in the north of Spain.

The manuscript describes a simplified methodology with which to assess the economic level of apparent losses (ELAL) in a water utility. This economic point corresponds to the break-even point for which the marginal benefit of increasing the frequency of the apparent losses’ reduction activities equalizes the marginal cost of their implementation. For this calculation, each apparent loss component, as defined by the International Water Association, has been subdivided into two additional categories. These categories have been established depending on how periodic activities conducted by the water utility to reduce apparent losses—namely water meter replacement and customers’ connection inspections—may affect their magnitude. It has been found that the ELAL is influenced by intervention costs, the degradation rate of the accuracy of water meters and water tariffs. In addition, this work defines a set of performance indicators to benchmark the apparent loss’s performance relative to the minimum achievable and optimum levels of the losses. Finally, two case studies on how the proposed calculation should be applied have been added to the appendices.