ABSTRACT: Regulators of water supply services have a major challenge to develop and implement a set of indicators to assess effectively water losses. You can find in the literature water loss indicators in different formats, making it difficult to assess the performance in combating losses between different water supply companies. In this
context, this article aims to investigate and describe documents that establish the normative basis of water loss indicators for the regulation of water supply services. A questionnaire to 44 regulatory agencies (27 states, 2 inter-municipals and 15 municipals) was sent, requesting information about the internal standards for water loss indicators. Subsequently, the set of indicators identified was compared with loss indicators adopted in the National Sanitation Information System (SNIS), observing variations in terminology, unit and formula indicators. The results show that there is still not a consolidated set of standardized loss indicators in Brazil. The main divergence between the indicators is the delimitation of the volume control, which does not always consider the volume of water imported, exported or service. Moreover, few regulatory sanitation agencies have internal rules for the standardization of loss indicators. Therefore, the Brazilian Association of Regulatory Agencies (ABAR) is still in the development phase of a set of performance indicators that can be used in the regulation of a standardized way of water supply services.
