In 2015, “The Sustainable Development Goals” (SDGs) were adopted by the United Nations as a call to action to protect the planet and natural resources. SDG number six deals with guarantee the availability of water and its sustainable management by 2030. Some of the main problems in water management are the decreasing annual rainfall and the expected rise of rainfall intensity and evaporation rate as a consequence of climate change, together with the growth of water demand. All that is particularly alarming in semi-arid regions and other domains, like the Mediterranean area, where water resources are very often dramatically stressed. In this scenario, Managed Aquifer Recharge (MAR) is considered an increasingly important water management strategy to enhance the quantity and quality of groundwater as a key step towards achieving the SDGs.
The selection of MAR techniques and the effectiveness of their design and implementation require a complete understanding of the physical/hydrogeological framework. This must include the definition of aquifer geometry and limits to estimate storage capacity, the assessment of hydraulic properties, the quantification of the groundwater budget, the establishment of reliable hydrogeological conceptual and numerical model, and the groundwater quality monitoring. Besides, the availability of water to be recharged is crucial. Many regions use stormwater (Perth, Australia) and wastewater (Alberta, Canada) to recharge aquifers via infiltration basins or wells and subsequently reuse this water for drinking use or irrigation purposes. Finally, social and economic drivers must also be taken into account.