Given the importance of reducing diverse forms of inequality in access to water, highlighted both in the framework of the Human Right to Water (HRW) and in the Sustainable Development Goals (SDG), this work assesses conditions of access to water and related inequalities before and after the construction of a Water Supply System (WSS) in a rural community of Brazil's semi-arid region. A quasi-experimental study was performed to assess the conditions of access to water for study and control groups (amounting to 380 households). The methodology encompassed two phases, one prior and another subsequent to the construction of a WSS in the study community. The analytical framework of the HRW was applied, specifically the normative content regarding quality, accessibility and availability. The case study's findings help to evidence the limitations and challenges of merely infrastructure-related measures to improve access to water. The construction of a new WSS in the studied community was an improvement as it provided water of good quality to the beneficiary households, which entailed a decreased or even a no-longer-existing need to collect water for children and adolescents. However, certain problems persisted, such as the continued practice of collecting water and the use, by certain families, of water that was fecally contaminated. In a different perspective, the WSS made it possible to increase the per capita volume of water consumed by families and to reduce inequalities associated with this aspect. Meanwhile, the research reveals the possible limits of the WSS in ensuring that higher volumes of water will be consumed per capita, especially among households without intra-household water distribution infrastructure.