Résumé
Groundwater constitutes a major water resource in Ethiopia, providing (Kebede,2013) 90% of domestic supply 95% of industrial uses, and 80% of the total national supplies. However, these groundwater resources are not evenly distributed as the geological framework is complex.An adequate management of this water resource is key for a sustainable use taking into consideration the impacts of climate change and growing demand. Managed Aquifer Recharge (MAR) constitutes a promising approach for managing existing assets and augment water availability in aquifers of Ethiopia and is not yet implemented at scale.The country has a geo-climatic context favorable for MAR projects whereby groundwater shall be considered as a water bank recharged during surplus surface water periods (rainy season) and pumped during the dry season. However, it shall be stressed that successful MAR implementation is not feasible everywhere and requires careful planning.A MoWE and BRGM scientific collaboration on MAR prefeasibility in eastern Ethiopia has started in 2023 with the support of the French Development Agency (AFD). This geographical area is considered an appropriate pilot with a favorable geoclimatic context (surplus of surface water during the rainy season and high reliance on groundwater during the dry season).The methodology makes use of existing geological and hydrogeological maps (1/250,000 scale), previous and on-going studies, and encompasses field work to evaluate lithology infiltration capacity and other parameters used in the multicriteria analysis. Alluvial aquifers in valleys south of the Rift escarpment (Somali region and East Haraghe zone of Oromia region) appear as promising targets for MAR schemes implementation: their catchments generate significant surface runoff during the rainy season and their porous lithology may store significant amount of additional water if the recharge is enhanced. These alluvial aquifers are key water resources tapped for the supply of Jijiga and Harar cities as well as local communities