Abstract. Environmental equity is a concept derived from the (un)equal exposure to environmental degradation by different social groups, usually minorities and low-income people exposed to major environmental risks, also known as environmental justice. It is assumed that no group of people, independent of race, ethnicity or socio-economic class, should support, either in concentrated or unevenly distributed form, the negative environmental impacts resulting from industrial, agricultural, commercial and infrastructure activities or government programs and policies. In this paper the concept of environmental equity is explored as a criterion for water management through the analysis of a typical coupled human–natural system: the Epitácio Pessoa Reservoir, located in the semi-arid region of Brazil. Inefficient water resource management has caused unequal access to water by the population, particularly during drought periods. However, census data indicate that population have practically the same access to water, which actually is not able to reflect the actual picture. This study argues that environmental equity can be an additional criterion to improve water management.

In water scarcity situations, water rationing is a management measure taken in order to ensure equitable access to water. The current study presents some factors that contribute to a situation of water injustice in Campina Grande, a city located in the Brazilian semiarid region, which has been facing a new drought cycle since 2012. The water supply conditions in the households and the users' perceptions about the impacts on their water use routines were monitored for 6 months. Two variables were considered: household income and water shortage risk. Among the main conclusions, the following stand out: (1) the higher the household income is, the higher the water storage capacity and the lower the impacts on the household routines; (2) the poorest sections of the population tend to naturalize the restrictive impacts of the water rationing since they have experienced and lived in a permanent state of water saving.

RESUMO Os sistemas de abastecimento em regime de intermitência fornecem água aos usuários por um período limitado de tempo, produzindo efeitos adversos à rede de abastecimento de água e aos usuários do sistema, em especial os usuários domésticos, cuja demanda é pouco flexível e a capacidade de adaptação limitada. Neste trabalho é proposto um conjunto simplificado de indicadores que permite identificar diferentes níveis de vulnerabilidade ao desabastecimento de água aos quais uma população urbana está sujeita em situação de intermitência no abastecimento. Os indicadores podem ser obtidos de dados censitários, de informações topológicas, topográficas e hidráulicas do sistema de abastecimento e de levantamentos cadastrais ou de sensoriamento remoto da localidade, podendo ser processados em Sistemas de Informações Geográficas (SIGs). Os indicadores são aplicados ao caso de Campina Grande, Paraíba, com base em levantamentos disponíveis sobre usuários que vivenciaram a situação de intermitência no abastecimento. Os resultados permitem a identificação das áreas cujos usuários podem ser potencialmente mais afetados pela intermitência no abastecimento e a recomendação de medidas mitigadoras para a redução de sua vulnerabilidade.