Sediment water storage investigation of check dams using electrical resistivity tomography

• ERT applied to check dams for the first time in the Mediterranean context. • The methodology proposed provides useful data with limited surveys and field samples. • Archie and Waxman-Smits laws with ERT allow the assessment of soil water content. • Check dams can hold unintended water storage potential within their sediment wedge. Our study aims to characterize the sediment wedges of check dams and the water retained within them to identify potential “reservoirs.” Shifting precipitation patterns in the Mediterranean region underscore the importance of improving effective water management strategies. In this contest, check dams can potentially enhance water infiltration and storage, similar to the role of sand dams in arid environments. Understanding water storage in Mediterranean check dams could improve regional water resilience and enhance water management strategies in similar European regions. To these aims, Electrical Resistivity Tomography (ERT) was used to investigate two check dam wedges in northern Tuscany (Italy). This non-invasive geophysical method is widely adopted for hydrological investigations due to its sensitivity to water and flexibility in survey design. The results reveal a clear contrast between the sediment wedge and the original riverbed at both study sites, with electrical resistivity values assessing the presence of water within the sediment. The use of ERT in this study has provided valuable insights into the lithology and water storage capacity of sediment wedges in Tuscan check dams. The results highlight the potential of check dams as “hidden reservoirs” and the usefulness of ERT for planning and monitoring water management strategies in Mediterranean regions.