Soil erosion is one of the main issues producing soil degradation in arid regions. In Tunisia, dry areas cover over 6300 km2 and are classified as 52% very and mediumly degraded and 48% between marginally and not degraded. The gabion check dam is an important structure that consists of a small dam constructed across the wadi to lower the velocity of flow and control upstream areas. Reduced runoff velocity in the wadi allows the settlement of sediments. Determining the sediment deposition behind gabions check dams is assumed to be an effective method of estimating the soil losses from small and medium catchments. This study aims to detect sediment at six gabions check-dams distributed in the upstream and downstream areas of the Koutine catchment, located in an arid area in the southeast of Tunisia and characterized by an annual mean precipitation of less than 200 mm. The detection of sediment is based on the Electrical Resistivity Tomography (ERT) as imaging technique used to study the subsurface properties of the Earth, such as the distribution of rocks, minerals and groundwater. It works by measuring the electrical resistivity of the subsurface materials. This method associated with topographic measurements. About ten lines were arranged, with 72 electrodes. The results of resistivity data obtained during field measurements were inverted into subsurface structures using least squares inversion techniques. The preliminary results indicate that the sediment can be identified using an ERT method. The obtained results are calibrated based on samples collected for laboratory analysis. The accuracy of the high-density ERT method was justified. The density increases with the sediment deposit depth. Topographic methods were used to estimate the surface and the relief of deposed sediments in the area monitored by the gabions check-dams. This study provides an approach based on the high-density electrical resistivity tomography method and a topographic investigation to estimate sediment yield behind gabion check-dams that control catchments. The sedimentary deposit of eroded soils reduces the effectiveness of the recharge structures. Consequently, the improvement of permeability at the level of the retention basins (by cleaning the settlement basin and creating recharge wells) is of great importance. The study results are beneficial for decision-makers to evaluate the existing soil conservation and water management plans, which can be further adjusted using appropriate soil erosion mitigation options based on scientific evidence.