Proposal of a systematic methodology to estimate apparent losses due to water meter inaccuracies

Apparent losses are integrated by four components: water meter inaccuracies, data pathway errors, unauthorized consumption, uncertainties in estimating unmetered consumption. Depending on the water utility and the local circumstances, each one of these components can adopt a larger or smaller importance. Obviously, accurate estimates of apparent losses components can be an invaluable tool for water utilities managers who, by having this information, will know how to make more profitable investments. Strangely enough, however, until now there has not been published a standard methodology that provides adequate guidelines to conduct a proper evaluation of water meter inaccuracies. The most probable reason is the complexity underlying this calculation, which involves the use of many parameters that are hardly understood. The lack of a standard methodology to calculate water meter inaccuracies can lead to different results, even in the case of analysing the same set of data. Consequently, water companies cannot compare their figures on metering errors with other utilities since they may have been obtained by applying different methodologies and might not be directly comparable. Taking this into consideration, this paper tries to define a basic methodology to calculate water meter inaccuracies.