Techno-Economic Analysis of Residential Water Meters: A Practical Example

Abstract

As water is a scarce natural resource, one of the most crucial aspects influencing its management is the measurement of user consumptions. There are many studies which set out to analyze issues related to water meter accuracy from either a technical or economical point of view. This investigation proposes an approach that integrates both technical and economic studies to advise in the error evaluation and the units renewal decisions. The technical study includes a methodology for measuring the error produced at different flow rates and an analysis of the results obtained. In the economic study three methods -linked to different management strategies -have been outlined to make an adequate appraisal of the water meter replacement time. The procedure was applied to the water meter park of a medium-sized Spanish city. Results indicate that both measured volume and age contribute to the error evolution, and that there was no noticeable influence regarding either the transmission type or the brand. In the economic study, specific results related to the water replacement were obtained, and a sensibility analysis revealed the influence of the price of water, water meter cost and the cost of capital.

A Strategy to Assess Water Meter Performance

“…Current research confirms that several factors affect a water meter's accuracy, particularly water meterage and total registered volume (Moahloli et al 2019;Pacheco et al 2020). Detecting the point in time in which water meters should be replaced implies that they can be substituted proactively to minimize the impact of water consumption nonregistration and under-registration on NRW (Moahloli et al 2019).…”

“…It is well known that mechanical water meters metrology becomes more and more inaccurate during their operating lifetime due to the "wear and tear" of the measuring components (Mutikanga et al 2011). As already mentioned, there are several studies [e.g., Arregui et al (2006Arregui et al ( , 2013 and Pacheco et al (2020)] that analyze the influence of parameters in the water meter metrology such as fatigue tests, depositions, incorrect water meter sizing, water consumption patterns, among others. Apparent losses occur due to inaccuracies in metering, illegal use, meter reading errors, data handling, and billing errors.…”

“…The decision to replace the water meter is of the water company's responsibility, which must weigh the cost-benefit of changing one or more meters. This decision analysis could gather the results already achieved with an econometric analysis of the optimum level of apparent losses, as described by Arregui et al (2018), or else a financial analysis as the one performed by Pacheco et al (2020), to increase the confidence on the timing of the water meter replacement.…”

“…A long-known fact is that reducing apparent losses caused by meter inaccuracies can result in substantial short-term increases in utility revenue and lead to increasingly equitable service charges for long-term water consumers (Richards et al 2010;Kadenge et al 2020). The accurate measurement of the water collected by meters is crucial in reducing any uncertainty affecting the water balance and has significant technical and economic implications (Pacheco et al 2020). A cubic meter consumed but not measured reduces the company revenue in quantity equal to the selling price of the last cubic meter of water consumed by that consumer (Arregui et al 2018).…”

“…Enhancing that water use efficiency and conservation are priority alternatives to ensure, for example, universal access to drinking water and reducing the number of people suffering from water scarcity. Furthermore, Pacheco et al (2020) emphasize that water measurement will become an even more critical aspect in the near future because of the increase in the world's water supplies due to population growth. In this context, one form of water companies to be aware of its important role is to steer the effective water consumption and guarantee an efficient manutention of its equipment, namely the water meters.…”