Evaluation of indicators applied to small water supply systems

Abstract

The aim of this study was to evaluate, by means of multiple linear regression (MLR), the indicators that best express the reality of small municipalities water supply systems, based on financial, operational and water quality performance as response variables. The organization and selection of the sample were based on the information available in the National Sanitation Information System of 2014, selecting 182 municipalities in Minas Gerais with population below 10,000 inhabitants and 56 indicators as explanatory variables. Through MLR, it was found that the commitment of revenue to expenditure (operating expense margin) and the ratio of collection to expenses (monetary sufficiency index) are the most relevant variables to describe financial performance. For the description of operational performance, the water loss per connection and water billing rates were the most recurrent. Finally, with regard to the performance of water quality, the models presented low determination coefficients and nonadherence of the residues to normal distribution.