Economic Valuation of Ancestral Artificial Aquifer Recharge Systems in High Mountain Environments of Sierra Nevada, Spain

The study applies a cost–benefit analysis approach to assess the ecosystem services provided by ancestral systems of artificial recharge of high mountain aquifers, the “acequias de careo” (careo channels), in the Bérchules River basin, located in the Sierra Nevada, Spain. The methodology is structured in three main phases: (i) the definition of scenarios and system boundaries; (ii) the selection of ecological, social, and economic indicators; and (iii) the monetary valuation of benefits in comparison with operation and maintenance costs. The findings indicate that the studied system generates social, environmental, and economic benefits exceeding €22.2 million per year, while its operation requires only €43,352 annually. This gives a benefit/cost (B/C) ratio of 512, demonstrating its extremely high social profitability. These results highlight the potential of such infrastructures as nature-based solutions that can enhance water availability both temporally and spatially, mitigate the impacts of extreme events (such as droughts and floods), and strengthen local resilience to climate change. Moreover, they contribute to cultural heritage preservation and promote community cohesion.