Managed Aquifer Recharge suitability mapping in Eastern Ethiopia (Dire Dawa, Harar, Jijiga areas)

International audience

English. Groundwater constitutes a major water resource in Ethiopia: according to Kebede (2013), groundwater provides 90% of domestic supply (including the supply of fast-growing cities such as Addis Ababa, Nazret, Gondar, Awasa, Dire Dawa, etc.), 95% of industrial uses, and 80% of the total national supplies. However, these groundwater resources are not evenly distributed as the geological framework of Ethiopia is complex. Managed Aquifer Recharge (MAR) is seen as an appropriate tool for managing existing assets and augment water availability in stressed aquifers of Ethiopia. The country has a geo-climatic context favorable to 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 anywhere and it requires careful planning.A scientific collaboration on MAR between the MoWE (Ministry of Water & Energy) and BRGM (French Geological Survey) has started in 2023 with the support of the French Development Agency (AFD). The main objectives of this collaboration are to develop a methodology for MAR suitability mapping at regional scale and then to carry out pre-feasability studies in two favorable areas. This pilot project is located around the towns of Dire Dawa, Harar, and Jijiga (eastern Ethiopia), a region where groundwater resources are critical to meet the growing water demand linked to population growth and development.The MAR suitability mapping is performed using existing datasets within a multi-criteria analysis framework. The main criteria are climate and precipitation, the proximity of runoff or watercourses, the proximity and the depth of sufficiently porous and permeable reservoir layers, and the predisposition of land to receive MAR. The resulting map is then validated by field surveys (geology and hydrogeology).