An Assessment of Groundwater Recharge at a Regional Scale for Sustainable Resource Management: Province of Alicante (SE Spain)

For decades, the Province of Alicante, located in the Southeast of Spain, has experienced important economic development associated with groundwater exploitation. The scarcity of superficial resources and irregular distribution in the time and space of rainfall, typical of the Mediterranean environment, together with the extensive limestone outcrops, have made groundwater a key resource for the area. However, insufficient knowledge about aquifers, especially the lack of precise recharge estimates, hinders regional water management. This study establishes updated recharge estimates and water budgets for the 200 aquifers found in Alicante, using readily usable methodologies and available data. These are soil water budget models, groundwater flow models, water table fluctuation methods, and spring flow analyses. The results show low mean annual values of recharge from precipitation (69 mm/year and a coefficient of 12%) and two main differentiated domains. The first one, in the northeast of the province, under more humid climatic conditions with larger carbonate aquifer systems, has higher recharge coefficients, ranging from 14% to 24%, and greater resources. For the rest of the province, where aquifers are smaller and annual averages of rainfall range between 250 and 400 mm, average recharge rates are low (9-12%).