Stakeholder perception for groundwater management from a subsidence point of view in the Guadalentín Valley (Spain)

Land subsidence produced from the exhaustive groundwater exploitation is a phenomenon that has critical effects in many areas around the world, especially in water-scarce areas. Among the objectives of the RESources managEment by integrating eaRth observation deriVed monitoring and flOw modelIng Results (RESERVOIR) project (GA nº 1924), one of them is the identification of the stakeholder requirements and groundwater conceptual model setup for several pilot sites. The present work is related with the Alto Guadalentín aquifer study case (SE Spain). To achieve the mentioned objective, a workshop was organized and a large number of potential stakeholders from local authorities, environmental agency, water supply companies, NGOs, insurance companies and regulatory institutions were summoned. During the workshop most important RESERVOIR activities were presented. Once the workshop was finished, a questionnaire that proposes the evaluation of the main problems in the area related to the groundwater management was sent to all participants. Results disclose that 55% of stakeholders consider that the principal problem in the Guadalentín aquifer is the overexploitation, and 50% of stakeholders regard that the lack of managerial, planning, and technical instruments are the most relevant issues to be addressed and solved. In more detail, the survey reveals that the monitoring coverage is inadequate in terms of: (a) groundwater levels monitoring (50%); (b) water quality measurement frequency (40%); and (c) water quality measurement points spatial distribution (55%) Even that area is reporting the highest subsidence rates in Europe, this problem is not considered as the most important, probably because affects agricultural areas and minimal damages were reported. Finally, 90% of the stakeholders have previous knowledge about groundwater modelling, but only 45% within them have information about the specific applications for which the model is employed in the Alto Guadalentín aquifer. Main conclusion leads to confirm that the measurements taken in the past have proved to be insufficient to reverse the state of the overexploitation of the aquifer. From this, some management measures must be strengthened, and several technical tools should be introduced to improve the groundwater management. On the other hand, improving the use of the numerical model of the Alto Guadalentín aquifer to support decision-making, as well as, updating the model by coupling it with the subsidence phenomenon through the definition of subsidence risk indexes would lead to a sustainable and holistic groundwater management.