This work presents a data-efficient procedure for distinguishing between leak and no-leak days using standard hourly smart meter readings. The approach relies on a fixed Minimum Night Flow window and classifies days based on the presence or absence of continuous registered volume during night hours. Applied to more than 21,000 users over one year, it is validated through the application of a Generalised Linear Mixed Model, which confirms that leak days exhibit systematically higher hourly volumes across the usage groups. The procedure also quantifies the hourly and daily impact of leakage and characterises its temporal organisation and influence on diurnal consumption patterns. Using only routinely available hourly data, it provides utilities with a practical framework for assessing post-meter leakage and enhancing the operational value of existing smart-meter infrastructures.

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.

In any water utility, a reliable assessment of the service life of the network pipes is a key piece within the big puzzle of assets management. This paper presents a new statistical model (basic pipes life assessment, BPLA) to assess the service life of pipes, to locate the pipes on the failures bath curve and to forecast the expected failures in future years. Its main novelties are the processing of pipe information (is that information what is adapted to the classical maintenance engineering and not the other way back) and the definition of two different time variables that can be analyzed in parallel. The first novelty makes the model less demanding in terms of data and software tools than others currently available, and the second one allows to get all the results after one single stage of calculation. To show its usability, the BPLA has been applied to a pipe network that supplies water to 500,000 citizens for which two years of failure records are available. Procedures and results have been compared to the well-known Weibull proportional hazard model (WPHM), with final relative errors lower than 10% and 15% on each particular result.

Photovoltaic energy production is nowadays one of the hottest topics in the water industry as this green energy source is becoming more and more workable in countries like Spain, with high values of irradiance. In water pressurized systems supplying urban areas, they distribute energy consumption in pumps throughout the day, and it is not possible to supply electromechanical devices without energy storages such as batteries. Additionally, it is not possible to manage energy demand for water consumption. Researchers and practitioners have proven batteries to be reliable energy storage systems, and are undertaking many efforts to increase their performance, capacity, and useful life. Water pressurized networks incorporate tanks as devices used for accumulating water during low consumption hours while releasing it in peak hours. The compensation tanks work here as a mass and energy source in water pressurized networks supplied with photovoltaic arrays (not electricity grids). This work intends to compare which of these two energy storage systems are better and how to choose between them considering that these two systems involve running the network as a standalone pumping system without being connected to electricity grids. This work also calculates the intermediate results, considering both photovoltaic arrays and electricity grids for supplying electricity to pumping systems. We then analyzed these three cases in a synthetic network (used in earlier research) considering the effect of irradiation and water consumption, as we did not state which should be the most unfavorable month given that higher irradiance coincides with higher water consumption (i.e., during summer). Results show that there is no universal solution as energy consumption depends on the network features and that energy production depends very much on latitude. We based the portfolio of alternatives on investments for purchasing different equipment at present (batteries, pipelines, etc.) based on economic criteria so that the payback period is the indicator used for finding the best alternative, which is the one with the lowest value.

One of the main difficulties encountered when designing automatic tools for water end-use identification is the inherent noise present in recorded flow traces. Noise is mainly caused by the inability of the monitoring equipment to accurately register water consumption and data-loggers to register, without distortion, the signal received from the water meter. A universal filtering algorithm has been developed to remove noise and simplify water consumption flow traces with the aim of improving future automatic end-use identification algorithms. The performance of the proposed filtering methodology is assessed through the analysis of 21,647 events. Water consumption data were sourced from two different water end-use studies, having consumers and monitoring equipment with dissimilar characteristics. The results obtained show that the algorithm is capable of removing an average of 70% of the data points that constitute the flow traces of the complex events examined. The simplified flow traces allow for faster and more accurate disaggregation and classification algorithms, without losing significant information or distorting the original signal. The ability of the proposed filtering algorithm to fit the original flow traces was benchmarked using the Kling-Gupta efficiency coefficient, obtaining an average value above 0.79.

Solar photovoltaic systems have become one of the most popular topics in the water management industry. Moreover, irrigation networks are water- and energy-hungry, and utility managers are likely to adapt water consumption (and consequently energy demand) to the hours in which there is energy availability. In countries such as Spain (with high irradiance values), solar energy is an available green alternative characterised by zero electricity costs and significantly lower environmental impact. In this work, several types of irrigation scheduled programmes (according to different irrigation sectors) that minimise the number of photovoltaic solar panels to be installed are studied; moreover, the effects of the variable costs linked to energy (energy and emissions costs) are presented. Finally, the effect of incorporating batteries for storing energy to protect the system against emergencies, such as unfavourable weather, is proposed. The irrigation hours available to satisfy water demands are limited by sunlight; they are also limited by the condition that the irrigation schedule type has to be rigid (predetermined rotation) and that the pressure at any node has to be above minimum pressure required by standards. A real case study is performed, and the results obtained demonstrate that there is no universal solution; this is because the portfolio of alternatives is based on investments for purchasing equipment at present and also on future energy savings (revenues). Apart from these two values, there is an economic value (equivalent discontinuous discount rate), which also influences the final results.

The work presented in this paper has a dual objective: on the one hand, reaching reliable estimates for the pipes lifespan in a water distribution network; on the other, doing so by means of a relatively low complex model with relatively low need for historical data. The model is based on using the Weibull distribution over two years of failure records. The results achieved are compared with those provided by the well-known Weibull proportional risk model, that have been applied on the same data sets. The comparison is positive in both the location on the Davis curve obtained for each group of pipes, and the relative error existing between both estimates of future failures.

En el presente trabajo se plantea el doble objetivo de, por una parte, alcanzar unas estimaciones fiables para la vida útil de las tuberías que conforman la red de distribución de un abastecimiento y, por otra, hacerlo mediante un modelo de, relativamente, baja complejidad y con poca necesidad de datos históricos. Dicho modelo se ha basado en la utilización de la distribución Weibull sobre registros de dos años de reparaciones. Los resultados alcanzados se han contrastado con los proporcionados por el modelo Weibull de riesgos proporcionales, de amplia difusión en la actualidad, aplicado sobre los mismos conjuntos de datos. La comparativa entre los resultados de ambos modelos ha resultado positiva tanto en la ubicación sobre la curva de bañera obtenida para cada grupo de tuberías, como en el error relativo existente entre ambas estimaciones de fallos futuros.

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.

The success of automatic water end use disaggregation and classification strategies greatly depends on the filtering and signal conditioning of the flow traces recorded. The work presented proposes a new filtering algorithm of water consumption flow traces. To improve the performance of the filter, the parameters driving the process are found per event by an automatically calibration procedure. These parameters are selected to ensure the maximum adaptability and simplification of the filtered flow traces. The methodology has been tested with 5210 consumption events obtained from a measurement campaign conducted in a Spanish city. The results obtained show that the filtering algorithm is capable of significantly simplifying the original flow traces while maintaining their main characteristics. On average, it has been found that the most complex events can be described using only 10% of the input data. This analysis can be used to make more efficient the filtering procedure proposed

El éxito de estrategias para la desagregación y clasificación automática de los consumos de agua en usos finales depende de un adecuado filtrado previo de las trazas de caudal registradas. Se propone un nuevo algoritmo de filtrado, cuyos parámetros de entrada se ajustan mediante un proceso de calibración automático por evento de consumo, asegurando la adaptabilidad y simplificación de la traza filtrada a la original. Esta herramienta se aplica a un caso de estudio mediante el análisis de 5210 eventos de consumo, procedentes de una campaña de monitorización en una ciudad española. Los resultados muestran que el filtro es capaz de simplificar sustancialmente las trazas de caudal manteniendo la información esencial. En media, las trazas de caudal de eventos más complejos pueden definirse con menos del 10% de los puntos de las trazas originales. Además, el análisis realizado permite identificar diversas estrategias para mejorar y optimizar el proceso de filtrado.

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.

Water distribution systems are made up of many interdependent elements that enable water supply to meet a demand that is variable in time and space. One of the main concerns for utility managers is quickly locating and repairing a leak after detection, during regular network water balance. This paper presents a two-stage methodology for locating a leak that is based on the hydraulic model of the network, and, particularly, on the conservation equations that govern network behaviour. In the first stage, the sensitivity of each element (nodes and pipes) is obtained for a given demand increase in any node. In the second stage, that sensitivity is combined with additional real data provided by the (possibly) existing pressure sensors and flowmeters installed throughout the network. As a final result, the system of equations thus obtained produces the theoretical leak flow at each network node that matches the network conditions. A subsequent analysis of the leak flows obtained highlights the node or nodes in which the leak is occurring. The presented methodology is applied and assessed in a case study.

Water meters are the cornerstone of commercial systems for water utilities throughout the world; revenue is directly derived from the, figures provided by meters. Despite this, little attention has been paid, in terms of selection, replacement period and return on investment, to the management and optimization of water meters. Integrated Water Meter Management is a comprehensive reference for engineers and managers alike, providing: Integrated Water Meter Management is an invaluable resource for those involved in urban water management, including water utility managers, engineering technical staff, operations and maintenance specialists, meter-reading personnel and scientific researchers in this discipline. Contents This title belongs to Water Research Foundation Report Series ISBN: 9781843390343 (Print) ISBN: 9781780402253 (eBook)

Pressurized Water Systems (PWS) is a key part of a drinking water supply service. Irrigation the greatest water consumer is shifting to PWS, making them a vital part of irrigation communities. PWS are energy-hungry. As population grows, water demand (for urban use and for irrigation) rises, and PWS require more energy (4% of total Europe energy, 2% agriculture, 12% drinking water) and, according Euroestat, may reach 100 TWh/year in 2013. In order to reduce greenhouse gas emissions (GHG), to improve PWS energy efficiency is crucial in the way to a lower carbon economy, one of the five key objectives of the Europe 2020 growth strategy.Minimize the energy demand of a network requires to analyze the system as a whole. With this general picture the efforts can be well addressed to the system's parts with higher margin of improvement (think globally, act locally). This paper outlines the procedure to minimize energy consumption of a PWS. Later, following the established protocol, a case study is presented. The analysis shows the huge margin of improvement that in practice can be found. The convenience of labelling PWS energy use is finally underlined. (C) 2013 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the CCWI2013 Committee

EPANET is one of the most widely used software packages for water network hydraulic modelling, and is especially interesting for educational and research purposes because it is in the public domain. However, EPANET simulations are demand-driven, and the program does not include a specific functionality to model water leakage, which is pressure-driven. Consequently, users are required to deal with this drawback by themselves. As a general solution for this problem, this paper presents a methodology for including leakage in EPANET models by following a two-stage process. Firstly, leakage is spatially distributed among the nodes, according to the characteristics of the network. Secondly, leakage is modelled through an emitter at each node. The process is described in detail and two numerical examples illustrate the applicability and advantages of the method. In addition, free access through a URL is provided to the leakage modelling tool that has been developed.