Decontamination of the Flix reservoir

The Flix reservoir is located in the County of Ribera de Ebro in the Province of Tarragona, Catalonia, Spain.

The execution of this project involves the removal of more than a century of toxic dumping into the River Ebro produced by the activities of the local industries. The cleaning process extracts the sludge, treats it and then returns the water in its natural state to the river

This project, declared as being of general, priority and urgent interest, responds to the principles of the AGUA (Actuaciones para la Gestión y Utilización del Agua - Actions for Water Management and Usage) Programme, which includes operations to improve water management and supply according to current and future needs linked to sustainable territorial development.

The first stage was the establishment of a protected enclosure by constructing a 1.3-kilometre long double wall to separate the work zone from the River Ebro course. The isolation is completed with the construction of secant pile wall on the right bank.

The second stage is based on the extraction of some 960,000 cubic metres of sludge contaminated by accumulated metals, organochlorine compounds and radioactive elements that have penetrated down to 150 metres depth in the river bed. The sludge is extracted by ecological dredging and is then treated by the plants installed in the area.

The treatment process consists of wet material classification in which they are separated in order to commence dehydration treatment of the silt.

All the water extracted by dredging and the various processes, will be treated at the water purification plant before being returned to the protected enclosure. Finally, all the material will be transported to a landfill, specifically constructed for this purpose.

The overall works include complementary actions, such as the installation of an emergency water supply for the townships located downstream on the River Flix and thus, prevent the risk of contamination and to protect the Sebes natural park, located on the bank opposite the factory.


Remarkable aspects

  • A decontamination project that is unique in the world.
  • 930,000 cubic metres of sludge will be extracted in order to remove heavy metals and other contaminating substances.
  • Improvement of the quality of water supplied to over one million people and used to irrigate more than 50,000 hectares.
  • Population safety guaranteed by periodic client controls, measurement of the actual project and the implementation of a Civil Protection Emergency Plan.

Cost: 165.0 M€

Client: Sociedad estatal Aguas de las Cuencas Mediterráneas

Start date: March 2013

End date: Under construction