Coastal areas are the most productive and economically dominant regions of the world. The high water demand in these regions, however, puts tremendous pressure on their freshwater resources and ecosystems. This leads to problems like seasonal water shortage, saltwater intrusion, and disappearance of wetlands.
Subsurface storage of freshwater in times of surplus (e.g. wet seasons) could be an option to improve the fresh water supply in water-stressed coastal areas. However, conventional aquifer storage and recovery (ASR) approaches often are unsuitable due to their low recovery efficiency in brackish and saline aquifers. Building on national, regional and European research and innovation programs, in the past decade, a set of innovative, practical concepts have been developed for protection, enlargement and utilization of freshwater resources in coastal areas. These concepts combine innovations in water well design and configuration, allowing for advanced groundwater management, and maximum control over freshwater resources. Full-scale pilots in the Netherlands have demonstrated the potential of these concepts to support sustainable freshwater supply in coastal areas, energy reduction, food production, and financial savings. Further pilot projects are currently being implemented in Denmark, Greece and Mexico.
Keywords: Water supply, coastal areas, seawater intrusion, salinization, Managed Aquifer Recharge, Aquifer Storage and Recovery