The Water Users Community from Llobregat Low Valley and Delta: An experience in the management of a coastal aquifer since 30 years old

Abstract

The Comunitat d’Usuaris d’Aigües de la Vall Baixa i Delta del Llobregat (Water Users Community from Llobregat Valley and Delta), is the oldest in Spain and it has recently celebrated its 30th anniversary. During its first 15 years, the quality of groundwater became worse because of the overexploitation of groundwater at the same time that the new urban and port infrastructures were introduced in this area. The following years were characterized by lower groundwater exploitation than before, but a lower aquifer recharge due to territory waterproofing and the losing of agrarian surface. All of these points are the cause of salt water intrusion in the Delta aquifer, especially in Prat de Llobregat zone. The challenge for the following years must be conditioned in order to keep quality aquifer recuperation by implanting different corrective and compensatory measures and aquifer evaluations considering the integral water cycle, the rainfall, the water level of river... By applying theses measures, the Baix Llobregat aquifers can recover their quality without an additional reduction of the groundwater abstraction compared to last years. For all these we must increase the artificial recharge infrastructures.