The unlined dry-stone rainwater cisterns known as souvales (σουβάλες) on Aegina island, Greece, are conventionally understood as passive rainwater reservoirs. This paper proposes a conceptual alternative: that Aegina’s unlined souvales may have operated, to varying degrees, as small-scale percolation structures analogous to the percolation tanks widely studied in peninsular India, forming part of a broader landscape-scale water management system, together with agricultural terraces, wells, streambeds, and the ancient aqueduct, that sustained terraced agriculture through seasonal groundwater recharge and capillary irrigation. The hypothesis rests on three interconnected propositions: (A) unlined souvales permitted controlled seepage into fractured volcanic bedrock, recharging localised perched aquifers; (B) this recharged groundwater, maintained at shallow depth, delivered moisture to root zones of downslope agricultural terraces via capillary rise, particularly during summer; and (C) the distribution of many small souvales (typically 10–20 m², depth 2–3 m) favoured effective recharge over fewer, larger structures. No prior study has, to the author’s knowledge, proposed or tested this recharge–capillary function for souvales on Aegina or elsewhere in the Aegean. Field observations supporting the hypothesis include the consistent absence of waterproofing materials in open souvales, the presence of entrance settling basins, and a spatial relationship between souvales and neighbouring wells at the Bourdechti plateau. This paper is a companion to the author’s earlier preregistration proposing Bronze Age origins for certain souvales (Psallidakos 2026, Zenodo record 18324574). It outlines testable predictions and a fieldwork protocol for hydrogeological verification, and argues for an integrated, interdisciplinary approach to the study and revival of Aegina’s traditional water heritage.
Ioannis Psallidakos (Mon,) studied this question.