Results of seawater intrusion in Mediterranean Spain and the Spanish islands according to the SASMIE report

Abstract

Groundwater salinization of the Spanish aquifers by seawater has been known for decades. However, in only a few cases has this been managed to control the damage, as salinization affects small territories and involves water rights that in practice remain largely in the private domain. Groundwater salinization affects many people and industrial, tourist and agricultural activities. The greatest problems appeared in the last decades of the 20th century. Some of them still persist but others have been dwindling as water from other origins rather than local ones has been made available to substitute existing pumped wells. The abandonment of part of the coastal aquifers as a freshwater resource is an important hydraulic inheritance loss and especially a decrease in the guarantee of water availability if other costly and environmentally less friendly structures are not incorporated. Global and climatic change may modify the current situation. Coastal aquifers can be recovered if the cost is proportionate. Seawater intrusion implies an impairment to general wellbeing due to enhanced corrosion, negative effects on agriculture, deterioration of wetlands, and a decrease in the ecologically important continental freshwater outflow to the ocean. All this goes beyond the scope of the aquifer good status of coastal groundwater bodies to be achieved according to the European Water Framework Directive. Long-term manag ement action is needed, both structural and non–structural. The current experience in Spain has been synthetized in the SASMIE (2017) report, developed by the Technical University of Catalonia with the support of SUEZ-Spain and the overview of CETAQUA, which centers on the Mediterranean and island areas of Spain. Some of the most relevant situations here are considered, based on the available data.