Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply

Abstract

Apparent losses are usually caused by water theft, billing errors, or revenue meter under-registration. While the first two causes are directly related to water utility management and may be reduced by improving company procedures, water meter inaccuracies are considered to be the most significant and hardest to quantify. Water meter errors are amplified in networks subjected to water scarcity, where users adopt private storage tanks to cope with the intermittent water supply. The aim of this paper is to analyse the role of two variables influencing the apparent losses: water meter age and the private storage tank effect on meter performance. The study was carried out in Palermo (Italy). The impact of water meter ageing was evaluated in laboratory by testing 180 revenue meters, ranging from 0 to 45 years in age. The effects of the private water tanks were determined via field monitoring of real users and a mathematical model. This study demonstrates that the impact on apparent losses from the meter starting flow rapidly increases with meter age. Private water tanks, usually fed by a float valve, overstate meter under-registration, producing additional apparent losses between 15% and 40% for the users analysed in this study.

Monitoring of water supply connections as an element to reduce apparent losses of water?

“…Since then, recipients have had doubts as to the metered water consumption [2,5,[9][10][11]. As technology developed, so too did monitoring.…”

“…The development of an advanced remote reading measuring structure introduced a new type of water meter, namely ultrasound and electromagnetic water meters. The combination of a traditional water meter and a data reading module led to the creation of a single, modern measuring device, which became a tool for remote control and monitoring of water consumption [9,10].…”

“…Apparent losses are mainly the result of low accuracy of measurement of the volume of flowing water and non-simultaneity of readings of devices registering the amount of water supplied to the system (main water meter) and consumed by recipients (sub-meters on premises) [1,2,9,10,16].…”

Gestão de perdas em sistemas de abastecimento de água: uma abordagem construtivista

“…Grande parte do volume de água fornecido aos usuários pode não ser contabilizada e/ou faturada. Causas que levam a essas perdas aparentes são de grande preocupação, uma vez que são as mais difíceis de serem controladas e estão relacionadas a medidas sociais e administrativas: intervenções fraudulentas, desatualização cadastral, parque de hidrômetros com idade ultrapassada, falta de calibração/manutenção, erros ou falta de medição (LAMBERT, 2000;MUTIKANGA et al, 2010;CRIMINISI et al, 2009).…”

Analysis of the impact of intermittent distribution by modelling the network-filling process

“…The tanks are located between the revenue water meter and the users' property, usually on rooftops, and are often over-designed to take into account possible higher water consumption and leakages (Arregui et al 2006;Cobacho et al 2008;Criminisi et al 2009). Therefore, node water demand does not depend on actual user consumption, but rather on the node water head.…”