Consumption estimation with a partial automatic meter reading deployment Karim Claudio, Vincent Couallier, Cyril Leclerc, Yves Le Gat and Jérôme Saracco ABSTRACT Automatic water meter reading (AMR) is now the best kind of technology to supply real time information on water consumption. Complete equipment of a district metered area enables the assessment of the total consumption of a finite size population, for a time scale sometimes as short as an hour. However, its cost for generalization can generate high capital expenditures (CAPEX), unaffordable for the utility, in which case sampling techniques have to be set up. With the purpose of total consumption estimation, this article describes standard methods of survey techniques applied to water networks and proposes a methodology for implementation of an operational sample. The methodology, which includes some constraints on the estimator precision, proposes a smart AMR equipment plan of the population, while reducing CAPEX. Finally, estimation of the total consumption, in addition to the knowledge of supplied volume, enables more accurate loss assessment and potential detection of new leaks. Karim Claudio (corresponding author) Cyril Leclerc LyRE (Lyonnaise des Eaux), 91 rue Paulin F-33000 Bordeaux, France E-mail: karim.claudio@lyonnaise-des-eaux.fr Karim Claudio Vincent Couallier Institut de Mathématiques de Bordeaux UMR 5251, 351 cours de la Libération, F-33405 Talence, France Yves Le Gat IRSTEA Bordeaux, team REBX, 50 av. de Verdun F-33612 Cestas, France Jérôme Saracco INRIA Bordeaux Sud-Ouest, team CQFD, 200 av. de la Vieille Tour, F-33405 Talence, France Key words | consumption estimation, reduction of CAPEX, regression calibration, stratified estimator, water automatic metering reading INTRODUCTION Problems linked to water have evolved through time and the current aim for water managers is the preservation of the resource. Losses in the French drinking water network rep- resent on average 20% of the annual volume delivered and reduction of lost volumes has become an important goal to achieve. Deducting the total consumption from the total supplied volume is the more accurate way to calculate losses. Despite an accurate knowledge of supplied water, data of total con- sumption are often available on a monthly or yearly time scale. Automatic meter reading (AMR) seems to be a sol- ution to this problem as it supplies consumption indexes at a time scale shorter than a day. However, the instrumen- tation of a whole district metered area (DMA) can either generate high capital expenditures (CAPEX) that are unbearable for some utilities or be too long (up to 10 years in some cases) to enable a direct exploitation of AMR data. In 2008, Lyonnaise des Eaux initiated a reflection pro- cess on the estimation of total consumption from a sample of meters equipped with AMR. The consumption estimator must be accurate enough to detect leaks on the network. Therefore, the sample has to fulfil some criteria (sample size, selection of the individuals in the sample) to generate a total consumption estimator with a controlled precision. The application of survey techniques in the case of a finite population is an answer to this issue. But, as we are dealing with longitudinal data, the efficiency of the sample worsens through time. If the initial estimator precision does not fulfil the criteria to reliably detect leaks on the water network, auxiliary information can be used to calibrate the estimator, improving its precision. From this estimation of a DMA total consumption, losses can be assessed and it would be possible to detect leakage. Other methodologies for a more accurate leakage 50 © IWA Publishing 2015 Water Science & Technology: Water Supply | 15.1 | 2015 doi: 10.2166/ws.2014.082 Downloaded from https://iwaponline.com/ws/article-pdf/15/1/50/414385/ws015010050.pdf by guest on 26 May 2020