Barcelona, Catalonia, Spain – Operating river augmentation
Barcelona city and its surrounding area, with a population of 5 million, is situated within the Catalan River Basin District (North East Spain), a region characterised by a Mediterranean climate that faces water scarcity and periodic droughts. For more than three years now, this area has been struggling with an unprecedented and remarkably persistent drought. The management of this challenging scenario involves a range of measures aimed at curbing consumption and diversifying water sources. Notably, supplemental resources such as seawater desalination and water reuse have taken on prominent roles, culminating in the recent implementation of indirect potable water reuse, beginning in November 2022.
The reclaimed water from the El Prat de Llobregat Reclamation Plant is pumped into the Llobregat River, eight kilometers upstream from the Barcelona drinking water treatment plant. The dilution ratio has been progressively increased, currently standing at approximately 1:1, involving an equal blend of reclaimed water and river water.
This measure is an integral component of the Catalan Drought Plan, launched by the Catalan Water Agency, specifically designed for scenarios of exceptional water scarcity. Its execution has been carefully developed over the past years, including a trial conducted in 2019. At that time, a comprehensive monitoring was undertaken to assess chemical and microbiological hazards across the water treatment process, the river, and the final drinking water. This encompassed the evaluation of 376 micropollutants as well as common microbiological indicators. These results showed the feasibility of the project. They also allowed for improvement of the inspection of industrial discharges into the sanitation network, prioritising certain chemical compounds that were found to be recalcitrant to treatment. The present success of the initiative owes a great deal to the insights gained from this preparatory test.
This initiative provides a crucial water resource during a period of severe scarcity. Its contribution represents 15% of the overall regional urban water demand in a region with 5 million inhabitants. It has helped to delay the most severe water restrictions.
Discharge of the reclaimed water into the Llobregat river, upstream of the Drinking Water Treatment Plant
Water reclamation plant of El Prat de Llobregat
Link to a journal article about the 2019 trial (open access):
Link to a video (in Catalan)