Managed Aquifer Recharge (MAR) has been widely used in various contexts throughout the world to overcome temporal scarcity in water supply for drinking, irrigation, or livestock. In scientific context, different methods prove successful to assess appropriate locations for MAR within a catchment, e.g. multi-criteria decision analysis, regional water budget analysis, numerical simulation or decision tree application. However, MAR is also considered a valuable method to support WASH-services (WAter, Sanitation & Hygienics) humanitarian context to overcome water shortages, despite the additional challenges due to data scarcity, planning uncertainties and time constraints.

Within the project presented here, a stepwise guideline is presented for humanitarian decision makers and local experts, assessing the potential and feasibility of MAR in their context. The stepwise procedure includes recommendations for three stages: initial evaluation, feasibility assessment and concept design. Furthermore, the reader is guided through various options for data gathering and interpretation, aiming at an appropriate MAR suitability and feasibility evaluation with the available data.

The procedure is demonstrated on a case study in Dollow, Somalia. The town plays a crucial role as a regional hub for the humanitarian support with more than 50,000 inhabitants and almost 140,000 internally displaced people (IDPs). The water supply relies strongly on the transboundary alluvial aquifer, shared by Somalia, Ethiopia and Kenya, which interacts strongly with the Dawa river. Water, sanitation and hygienics-services (WASH) are provided by different humanitarian actors.

Even though the aquifer offers sufficient yield for the moment, concerns are growing with regard to longer periods of dryness and the long-term impact of increased water abstraction. MAR is generally considered an appropriate countermeasure, but impact and feasibility need to be assessed beforehand. Following the aforementioned guideline, a monitoring and exploration campaign is developed, including site exploration with straightforward geophysics (i.e., transient electromagnetics), water level monitoring and local questionnaire surveys. The obtained data are interpreted with a simple numerical model of the subcatchment.

The study highlights the potential of MAR for humanitarian context as well as the importance of appropriate evaluation beforehand, including demand quantification, socio-economic analysis and hydro(geo)logical process modeling under challenging conditions to identify the main drivers for a successful MAR implementation.