Avaliação de indicadores aplicados a sistemas de abastecimento de água em Minas Gerais segundo portes populacionais

Abstract

Financial, operational and water quality performances are important indicators to evaluate water supply systems. However, these are highly heterogeneous services which may be affected by kind of service provider and size of the system. Taking this into consideration, it is possible to conclude that different size of water supply systems demands differentindicators. Under this assumption, the overall aim of this research was to evaluate performance indicators for water supply services focusing on population size. The methodology used during the study consisted of three main steps: (i) sample organization and selection, (ii) modelling equations by Multiple Linear Regression (MLR) and (iii) statisticalcomparisons and evaluating results. The selected sample was obtained at National Sanitation Information System (SNIS), an annual survey that allows evaluating the water supply services in Brazil. This study assessed the sample quality of 804 municipalities and 75 indicators.From these, 363 municipalities and 55 indicators were picked up using interquartile range method and technical criteria. During the analysis, it was verified by MLR that percentage of revenue intended for expenses payment as well as relation between tax revenues and expenses are the most significant variables to describe the financial performance. In the same way, water losses and water billing are the most significant variables to describe the operational performance. Finally, to describe the water quality performance, the models created were inconclusive due of low coefficients of determination and unsatisfying residual distribution.Therefore, this study concludes that different water supply systems need distinct information to describe their performance. In addition, it presents a way to improve the quality of water services by assertive decision making