Technical feasibility framework for sand dams applied to Eastern Chad

This paper focuses on the technical aspects of sand dams, establishing a feasibility framework comprised of three criteria with which to evaluate sand dam suitability. Sand dams are an effective and affordable type of rainwater harvesting technology for arid regions. However, they must only be undertaken in specific contexts where conditions are favourable. Adequate water supply must be ensured by considering the region’s rainfall and geology. Sufficient storage capacity will depend on the volume of sand behind the dam and the river’s sediment characteristics. Affordability will be determined by the availability of construction materials, the dimensioning of the dam, and users’ willingness to pay. This feasibility framework is applied to Hadjer Hadid in eastern Chad, where eleven prospective sand dam sites are analysed. 72% of the sites are considered favourable; on this basis, sand dams are considered a viable option for addressing water needs in eastern Chad.