AbstractThe pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2020 led to a significant change in human behaviors, mainly because of the quarantine to avoid the spread of the virus. Measures affected both economic activities and citizens’ behaviors as they developed more intense hygiene habits to avoid contamination and switched to home offices. These exceptional behaviors also affected the way that water is consumed and need to be fully understood to manage supply systems. Therefore, this study aims to investigate changes in residential and commercial water consumption in 31 municipalities in the state of São Paulo, Brazil, during SARS-CoV-2. To do this, the expected consumption for the first half of 2020 was forecasted using the Holt-Winters multiplicative method and compared with the data observed for the same period. In addition, we compared monthly records of new contaminations and the social distancing index to establish a correlation with changes in water consumption. The results show an average difference between forecasted and observed consumption equal to +6.23% and −18.59% for residential and commercial activities, respectively. For the first one, the consumption per capita increased at the rate of 8.44 L.person−1.day−1. The observed changes in consumption seem to be a consequence of hygiene habits, social distancing and the closing of nonessential services in commerce.