Indicadores de desempeño para servicios de abastecimiento de agua

Esta obra es fruto de la traducción al español del libro de Indicadores de desempeño para servicios de abastecimiento de agua de la International Water Association.Se trata del segundo libro de una serie de tres traducciones de manuales de buenas prácticas de la IWA que están viendo la luz gracias al compromiso del grupo Global Omnium con la mejora de la gestión de los servicios urbanos de agua. El manual que tiene ante sí es ya todo un clásico que fue actualizado hace apenas un año y medio en su versión inglesa. Se trata sin duda de la referencia en todo el mundo para desarrollar sistemas de evaluación del desempeño con el uso de indicadores, hasta el punto que resulta prácticamente imposible encontrar un artículo o trabajo sobre este asunto que no referencie esta obra. Por ello, debe tomarse como un punto de partida más que uno de llegada. El manual proporcionará los fundamentos de la evaluación del desempeño y las claves para acometer la misma con éxito en un servicio de abastecimiento de agua. Para los más experimentados, este manual siempre será una obra de referencia a la que volver cuando surjan dudas.Cabrera Rochera, E. (2021). Indicadores de desempeño para servicios de abastecimiento de agua. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/164874EDITORIA

La regulación de los servicios urbanos de agua. Experiencias para analizar desde España

La creciente complejidad del ciclo del agua urbano, el aumento poblacional, los exigentes estándares de calidad a satisfacer y unas fuentes de suministro cada vez más estresadas(en calidad y cantidad) recomiendan ordenarlo y regularlo.Porque,además, se tiene la obligación de legarlos a las generaciones venideras libres de hipotecas ya que sólo así podrán disfrutarlo con un nivel de calidad similar al actual. No conviene olvidar que en 2010 Naciones Unidas declaró derecho humano fundamental, para las presentes y futuras generaciones, el acceso seguro al agua potable y al saneamiento.Siendo, pues, objetivo estratégico, es responsabilidad de los gobiernos controlar su desempeño en las vertientes integradas en el concepto de sostenibilidad.La social (vigilar la calidad del agua potable y garantizar el derecho universal), la ambiental (utilizar el agua necesaria, devolviéndola al medio receptor depurada) y la económica (recuperar todos los costes para mantener la calidad del servicio y la independencia económica).Siendo, pues, objetivo estratégico, es responsabilidad de los gobiernos controlar su desempeño en las vertientes integradas en el concepto de sostenibilidad. La social(vigilar la calidad del agua potable y garantizar el derecho universal), la ambiental (utilizar el agua necesaria, devolviéndola al medio receptor depurada) y la económica (recuperar todos los costes para mantener la calidad del servicio y la independencia económica).Cabrera Marcet, E.; Cabrera Rochera, E. (2016). La regulación de los servicios urbanos de agua. Experiencias para analizar desde España. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/74591EDITORIA

Strategies to improve the energy efficiency of pressurized water systems

[EN] As time goes by, the need to move water is greater and this water will be pressurized. Layout flexibility, security, quality care, control, lower environmental impact and higher efficiency justify pressurized transport rather than natural gravitational water transport. On the negative side, we find the enormous amount of energy pressurized systems require with the associated negative economic and environmental impacts. Therefore, it is crucial to minimize these impacts and that only can be achieved by improving the energy efficiency of these systems. To achieve that final goal, the first step is to perform an assessment to estimate the margin of improvement from the actual performance of the system to the maximum achievable level of efficiency [1]. The second step is to perform an energy audit in order to identify exactly how the energy is used and where it is lost [2], with the third step being identification of the different actions that can be implemented in practice in a system. The final step is to perform the cost benefit analysis of the selected actions to prioritize execution. The focus of attention of this paper is on the third step, actions that can be classified in operational actions (do not require investments) and structural actions (require investments).Cabrera Marcet, E.; Gomez Selles, E.; Espert Alemany, VB.; Cabrera Rochera, E. (2017). Strategies to improve the energy efficiency of pressurized water systems. Procedia Engineering. 186:294-302. doi:10.1016/j.proeng.2017.03.248S29430218

Discussion of Energy Metrics for Water Distribution System Assessment: Case Study of the Toronto Network by Rebecca Dziedzic and Bryan W. Karney

[EN] The paper under discussion presents a metric that allows auditing the energy performance of pressurized water networks. This same metric (except for the period used to perform the audit) was already presented by the discussers in this journal (Cabrera et al. 2010). In the discussers opinion, this poses a minor difference from a conceptual point of view. While in the discussers proposal integration was extended to longer periods (days or years) to gain a general understanding of the issue, the paper under discussion uses shorter periods of time similar to those used to analyze network behavior with extended period simulation. The increased time resolution allows delving into greater depth in the assessment as well as developing and comparing different scenarios (e.g., winter versus summer).Cabrera Marcet, E.; Gomez Selles, E.; Cabrera Rochera, E.; Arregui De La Cruz, F. (2016). Discussion of Energy Metrics for Water Distribution System Assessment: Case Study of the Toronto Network by Rebecca Dziedzic and Bryan W. Karney. Journal of Water Resources Planning and Management. 142(11):07016003-1-07016003-3. doi:10.1061/(ASCE)WR.1943-5452.0000721S07016003-107016003-31421

Private Water Storage Tanks: Evaluating Their Inefficiencies

[EN] Private water storage tanks are often considered as very inefficient devices than can only be justified in systems that suffer frequent water service interruptions. This paper presents the results obtained after studying four different aspects of this question: the effect of this kind of tanks on water losses, unaccounted for water, time modulation curve and energy losses (other implications, such as those related to water quality deterioration, remain out of the scope of the study). Conclusions for each particular point will turn uneven, specially highlighting the effect on the meter global error and unregistered water. In any case, all four points, as well as several additional issues to be considered, are described and evaluated.Authors would like to thank the essential support of SPANISH MINISTRY OF EDUCATION, through the research project “Ordenación y valoración de estrategias orientadas a la progresiva eliminación de los depósitos de almacenamiento de los usuarios en los abastecimientos de agua urbanos”. CGL2005-03666/HID.Cobacho Jordán, R.; Arregui De La Cruz, F.; Cabrera Marcet, E.; Cabrera Rochera, E. (2008). Private Water Storage Tanks: Evaluating Their Inefficiencies. Water Practice & Technology. 3(1):1-8. https://doi.org/10.2166/wpt.2008.025S183

Target Audience Analysis

Knowledge, tools and technologies generated through TRUST must be available to a wide range of professional and lay communities. Each audience and local circumstances are different, and they need appropriate formatted material and communication vehicles that succeed in delivering the right message for each audience and situation. Addressing researchers, technical staff and policy-makers is a completely different task for each type of individual. This task differs even more depending on the geographic location of the intended target because it needs to adapt to the economic, social and environmental context. Transition roadmaps in both the form and management of urban water services will obviously be different between a Northern European, an African or a Mediterranean city. The communication strategy should be present in all deliverables from the project, with clear objectives and target audiences, obtaining an overall impact that is greater than the sum of the parts. TRUST cannot be understood as a mere media production center with uncertain target groups. Deliverables will aim specific target audiences and their contents will be shaped and adapted accordingly, a process that can be understood backwards. Deliverables will be designed and intended to target specific groups. The goal of generating a lasting legacy of TRUST contribution to a broad stakeholder community reinforces the need of this standpoint. The Target Audience Analysis poses as a guideline to reach this goal.Cabrera Marcet, E.; Cabrera Rochera, E.; Del Olmo Garcia, AJ. (2012). Target Audience Analysis. http://hdl.handle.net/10251/4662

Energy Assessment of Pressurized Water Systems

[EN] This paper presents three new indicators for assessing the energy efficiency of a pressurized water system and the potential energy savings relative to the available technology and economic framework. The first two indicators are the ideal and real efficiencies of the system and reflect the values of the minimum energy required by users the minimum amount of energy to be supplied to the system (because of its ideal behavior) and the actual energy consumed. The third indicator is the energy performance target, and it is estimated by setting an ambitious but achievable level of energy loss attributable to inefficiencies in the system (e.g., pumping stations, leakage, friction loss). The information provided by these three key performance indicators can make a significant contribution towards increasing system efficiency. The real efficiency indicator shows the actual performance of the system; the energy performance target provides a realistic goal on how the system should be performing; and finally, the ideal efficiency provides the maximum and unachievable level of efficiency (limited by the topographic energy linked to the network topography). The applicability and usefulness of these metrics will be demonstrated with an application in a real case study.The authors acknowledge the very valuable contributions made by the reviewers of this paper, because their comments and suggestions have helped to significantly improve the contents. Additionally, we thank the staff of Aguas de Valencia for providing helpful advice and real case studies used to tune the software tool developed based on this paper. And last but not least, the research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 265122. The translation of this paper was funded by the Universitat Politècnica de València, Spain.Cabrera Marcet, E.; Gomez Selles, E.; Cabrera Rochera, E.; Soriano Olivares, J.; Espert Alemany, VB. (2014). Energy Assessment of Pressurized Water Systems. Journal of Water Resources Planning and Management. 141(8):1-12. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000494S112141

Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty

[EN] The regulation of water services shares many similarities with that of other utilities such as electricity or telecommunications. As a result, similar methods are often used by regulators to assess the efficiency of companies in those sectors. Data Envelopment Analysis (DEA) is one of those widely applied methods. This paper aims to determine the adequacy of DEA as a regulatory tool for urban water services, with a special focus on the quality of the available data. In order to obtain useful conclusions, two DEA simulations were performed with audited data from 194 water utilities, officially made available by the Portuguese water regulatory authority (ERSAR). Both simulations will demonstrate that the inherent inaccuracies found in some of the key data provided by water utilities represent a significant obstacle to obtain meaningful results with the DEA technique. This could represent a paradigm shift for some of the regulatory authorities currently using DEA or similar techniques, as the complexity of the method does not seem to be justified by a better analysis of the comparative performance of the different services.Cabrera Rochera, E.; Estruch-Juan, ME.; Molinos-Senante, M. (2018). Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty. Environmental Science & Policy. 85:155-162. https://doi.org/10.1016/j.envsci.2018.03.028S1551628

Are Frontier Effiency Methods Adequate to Compare the Effiency of Water Utilities for Regulatory Purposes?

[EN] Frontier efficiency methods have been recurrently used in the water sector to assess the performance of water utilities. These methods are also used for yardstick regulation, with greater efficiency being sought by creating competition between the utilities, which can have an impact on decision-making processes, such as tariff setting. This study analyzes the adequacy and limitations of these methods for regulatory purposes, particularly how they deal with data uncertainty and their capacity to manage large number of variables. In order to achieve this, two representative methods¿a nonparametric technique (data envelopment analysis) and an econometric one (stochastic frontier analysis)¿are applied to an audited sample of 194 water utilities. Results will show that the results from the methods may not be considered conclusive in the water sector and their application should be carried out with considerable reservations.Estruch-Juan, E.; Cabrera Rochera, E.; Molinos-Senante, M.; Maziotis, A. (2020). Are Frontier Effiency Methods Adequate to Compare the Effiency of Water Utilities for Regulatory Purposes?. Water. 12(4):1-16. https://doi.org/10.3390/w12041046S116124Posner, R. A. (1969). Natural Monopoly and Its Regulation. Stanford Law Review, 21(3), 548. doi:10.2307/1227624Shleifer, A. (1985). A Theory of Yardstick Competition. The RAND Journal of Economics, 16(3), 319. doi:10.2307/2555560Eficiencia y su Medición en Prestadores de Servicios de Agua Potable y Alcantarillado http://hispagua.cedex.es/sites/default/files/hispagua_documento/documentacion/documentos/eficiencia_agua_potable_alcantarillado.pdfAbbott, M., & Cohen, B. (2009). Productivity and efficiency in the water industry. Utilities Policy, 17(3-4), 233-244. doi:10.1016/j.jup.2009.05.001Ferro, G., Lentini, E. J., Mercadier, A. C., & Romero, C. A. (2014). Efficiency in Brazil’s water and sanitation sector and its relationship with regional provision, property and the independence of operators. Utilities Policy, 28, 42-51. doi:10.1016/j.jup.2013.12.001Byrnes, J., Crase, L., Dollery, B., & Villano, R. (2010). The relative economic efficiency of urban water utilities in regional New South Wales and Victoria. Resource and Energy Economics, 32(3), 439-455. doi:10.1016/j.reseneeco.2009.08.001Thanassoulis, E. (2000). The use of data envelopment analysis in the regulation of UK water utilities: Water distribution. European Journal of Operational Research, 126(2), 436-453. doi:10.1016/s0377-2217(99)00303-3Pourhabib Yekta, A., Kordrostami, S., Amirteimoori, A., & Kazemi Matin, R. (2018). Data envelopment analysis with common weights: the weight restriction approach. Mathematical Sciences, 12(3), 197-203. doi:10.1007/s40096-018-0259-zDe Witte, K., & Marques, R. C. (2010). Influential observations in frontier models, a robust non-oriented approach to the water sector. Annals of Operations Research, 181(1), 377-392. doi:10.1007/s10479-010-0754-6Berg, S., & Marques, R. (2011). Quantitative studies of water and sanitation utilities: a benchmarking literature survey. Water Policy, 13(5), 591-606. doi:10.2166/wp.2011.041Worthington, A. C. (2013). A review of frontier approaches to efficiency and productivity measurement in urban water utilities. Urban Water Journal, 11(1), 55-73. doi:10.1080/1573062x.2013.765488Aigner, D., Lovell, C. A. K., & Schmidt, P. (1977). Formulation and estimation of stochastic frontier production function models. Journal of Econometrics, 6(1), 21-37. doi:10.1016/0304-4076(77)90052-5Meeusen, W., & van Den Broeck, J. (1977). Efficiency Estimation from Cobb-Douglas Production Functions with Composed Error. International Economic Review, 18(2), 435. doi:10.2307/2525757Cullmann, A. (2010). Benchmarking and firm heterogeneity: a latent class analysis for German electricity distribution companies. Empirical Economics, 42(1), 147-169. doi:10.1007/s00181-010-0413-4Ferro, G., & Mercadier, A. C. (2016). Technical efficiency in Chile’s water and sanitation providers. Utilities Policy, 43, 97-106. doi:10.1016/j.jup.2016.04.016Saal, D. S., Parker, D., & Weyman-Jones, T. (2007). Determining the contribution of technical change, efficiency change and scale change to productivity growth in the privatized English and Welsh water and sewerage industry: 1985–2000. Journal of Productivity Analysis, 28(1-2), 127-139. doi:10.1007/s11123-007-0040-zMolinos-Senante, M., Porcher, S., & Maziotis, A. (2017). Impact of regulation on English and Welsh water-only companies: an input-distance function approach. Environmental Science and Pollution Research, 24(20), 16994-17005. doi:10.1007/s11356-017-9345-2Kuosmanen, T. (2011). Stochastic Semi-Nonparametric Efficiency Analysis of Electricity Distribution Networks: Application of the StoNED Method in the Finnish Regulatory Model. SSRN Electronic Journal. doi:10.2139/ssrn.1806867Jamasb, T., Orea, L., & Pollitt, M. (2012). Estimating the marginal cost of quality improvements: The case of the UK electricity distribution companies. Energy Economics, 34(5), 1498-1506. doi:10.1016/j.eneco.2012.06.022ERSAR—Relatório Anual dos Serviços de Águas e Resíduos em Portugal http://www.esgra.pt/ersar-relatorio-anual-dos-servicos-de-aguas-e-residuos-em-portugal/Marques, R. C., Berg, S., & Yane, S. (2014). Nonparametric Benchmarking of Japanese Water Utilities: Institutional and Environmental Factors Affecting Efficiency. Journal of Water Resources Planning and Management, 140(5), 562-571. doi:10.1061/(asce)wr.1943-5452.0000366Pinto, F. S., Costa, A. S., Figueira, J. R., & Marques, R. C. (2017). The quality of service: An overall performance assessment for water utilities. Omega, 69, 115-125. doi:10.1016/j.omega.2016.08.006Matos, R., Cardoso, A., Duarte, P., Ashley, R., Molinari, A., & Schulz, A. (2003). Performance indicators for wastewater services - towards a manual of best practice. Water Supply, 3(1-2), 365-371. doi:10.2166/ws.2003.0126Alegre, H., Baptista, J. M., Cabrera, E., Cubillo, F., Duarte, P., Hirner, W., … Parena, R. (2016). Performance Indicators for Water Supply Services: Third Edition. Water Intelligence Online, 15(0), 9781780406336-9781780406336. doi:10.2166/9781780406336Cabrera, E., Estruch-Juan, E., & Molinos-Senante, M. (2018). Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty. Environmental Science & Policy, 85, 155-162. doi:10.1016/j.envsci.2018.03.028Molinos-Senante, M., Donoso, G., & Sala-Garrido, R. (2016). Assessing the efficiency of Chilean water and sewerage companies accounting for uncertainty. Environmental Science & Policy, 61, 116-123. doi:10.1016/j.envsci.2016.04.003Picazo-Tadeo, A. J., Sáez-Fernández, F. J., & González-Gómez, F. (2008). Does service quality matter in measuring the performance of water utilities? Utilities Policy, 16(1), 30-38. doi:10.1016/j.jup.2007.10.001Berg, S., & Lin, C. (2008). Consistency in performance rankings: the Peru water sector. Applied Economics, 40(6), 793-805. doi:10.1080/00036840600749409Ferro, G., & Romero, C. A. (2011). Setting performance standards for regulation of water services: Benchmarking Latin American utilities. Water Policy, 13(5), 607-623. doi:10.2166/wp.2011.042Molinos-Senante, M., & Maziotis, A. (2019). Productivity growth and its drivers in the Chilean water and sewerage industry: a comparison of alternative benchmarking techniques. Urban Water Journal, 16(5), 353-364. doi:10.1080/1573062x.2019.1669196Corton, M. L., & Berg, S. V. (2009). Benchmarking Central American water utilities. Utilities Policy, 17(3-4), 267-275. doi:10.1016/j.jup.2008.11.00

Calculating the Economic Level of Friction in Pressurized Water Systems

[EN] In this paper, an algebraic expression is presented to determine the optimum hydraulic gradient (J(0)) in a pressurized water system. J(0) represents the economic level of friction losses (ELF), which is dependent on the network's behavior as well as other parameters, including energy and the pipe costs. As these have prices changed over time, so has the value of J(0). The network-related parameter was obtained from the total costs function and the sum of the operational and capital expenditures. Because these costs exhibited an opposite trend from J, a minimum total cost exists, specifically, J(0). The algebraic expression, which was derived from the mathematical model of the network, was first calculated for the network's steady state flow and was later generalized for application to a dynamic one. For a network operating in a given context, J(0) was fairly stable in terms of dynamic flow variations, providing valuable information. The first piece of information was the ELF itself, which indicated the energy efficiency of the system from the perspective of friction loss. The second indicated which pipes required renewal from a similar perspective. Thirdly, it provided a simple criterion to calculate the diameter of new pipes. Finally, as J(0) can be easily updated, when predictions are performed at the network's designed time fail (e.g., growing urban trends, demand evolution, etc.), decisions can also be updated.Cabrera Marcet, E.; Gomez Selles, E.; Cabrera Rochera, E.; Soriano Olivares, J. (2018). Calculating the Economic Level of Friction in Pressurized Water Systems. Water. 10(6):1-21. https://doi.org/10.3390/w10060763S12110