The Volumetric Potentials of Rain-Harvesting Cisterns to Shape Hydrosociality in the Semiarid Region of Ceará, Northeast Brazil

This article uses a volumetric lens to explore how household rain-harvesting cisterns help (re)shape hydrosocial relations across the semiarid region of Ceará, Northeast Brazil, where vulnerability to climate variability remains high among the rural poor. Building from a multivalent understanding of volume as capacity, this article integrates hydrosocial perspectives, feminist political ecology, and theories of nonhuman agency from science and technology studies (STS) to examine how the cistern’s potential to increase water security and democratise water access emerges through its 16,000-liter capacity and the sociopolitical values it embodies. Participant observation is triangulated with data from a mixed-methods household survey carried out during the 2022 rainy season (n = 347 households) and repeated during the dry season (n = 337 households), semi-structured interviews, and archival research. While federal cistern programs have decreased water-related vulnerability of rural families, cisterns remain entangled in the legacies of patronage relations they seek to disrupt. Attention to the ways rural dwellers in the sertão, or hinterlands, of Ceará adapt to cisterns’ ‘leaky volumes’ reveals how volume itself is a state of flux rather than a fixed measurement to calculate storage capacity.