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Juan Antonio López-Geta, IGME (Spain)
Loreto Fernández, IGME (Spain)
Alberto Batlle, EPTISA (Spain)
Ana Castro, EPTISA (Spain)
Luis Ocaña, TRT (Spain)
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Renewable groundwater resources in Spain had been estimated in 20,800 hm3/a and groundwater exploitation in 5,900 hm3/a. Current knowledge allows to increase both values in 1,000 hm3/a. More than half of the total resources are considered non-exploitable, necessary for environmental uses. Exploitable groundwater resources are used in Spain unevenly. While in some Autonomous Regions there is an overexploitation of the resources, in others there is very little use of groundwater. In absolute terms, the greatest use of groundwater takes place in the Region of Valencia, in the Mediterranean coast. In Spain, 62% of the groundwater is used for irrigation, while around 20% is used for human consumption.
Quality indicators are for saline and nitrate contaminated groundwater. The objectives proposed for each indicator are respectively continuity of the exploitation and reduction of contamination. Saline water assessment is based on conductivity and chloride concentration data. The greatest problems with saline groundwater are located in the Mediterranean coast and the Canary and Balearic Islands, and are associated to seawater intrusion. However, the autonomous region with the greatest saline groundwater problems is La Rioja, in interior Spain, due to lithological reasons.
In Spain, 12.7% of its area has been designated as a Nitrate Vulnerable Zone. The main regions with nitrate values over 50 mg/l are located in the autonomous regions of Valencia and Murcia, although there are high nitrate concentration values in many regions.
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