Pre-demolition work for removal of Foz Côa Cofferdams, Portugal

Restoring connectivity between the Côa River, Massueime Stream, and the Douro River.


The Greater Côa Valley is a culturally rich and biodiverse area close to the border between Portugal and Spain, in the northwest of Portugal, in the district of Guarda. Its broad range of habitats and species has made it one of Portugal’s most exciting wild areas. The rural exodus and consequent abandonment of marginal land present an unprecedented, large-scale opportunity for rewilding and the comeback of wildlife, with more than 210 species of vertebrates already present, including several keystone species. 

The Côa River flows 140 km from Serra das Mesas in the Malcata Mountains running into the Douro River and connecting Malcata Nature Reserve to the Douro International Park. Along its course, it creates a great diversity of habitats and conditions, from the rich riparian forests and large flood plains in the south to spectacular gorges that are home to cliff-nesting raptors and vultures in the north.  Its basin, mostly granitic, covers an area of 2520 km2 and comprises 25 sub-basins. This project focuses on the Côa River and its tributary, the Massueime Stream. 

In the upper Côa River, more than 80 sites of rock art and around 1200 engraved outcrops can be found, including the most important collection of Palaeolithic open-air figurations known nowadays, which lead to the creation of the Côa Valley Archaeological Park in 1996 with the mission of managing, preserving, researching and showing to the public the rock art. The Great Route of the Côa Valley goes by the river, from the start to the end allowing visitors to discover the spectacular natural, archaeological and cultural heritage of the region. 

At a glance

Project typeDam removal: pre-demolition
Project statusLive
RiverCôa and Massueime
Km to be opened57
Focal speciesUnio crassus, Ciconia nigra, Anguilla Anguilla, Luciobarbus bocagei, Squalius alburnoides, Squalius carolitertii, Pseudochondrostoma duriense

Project context and opportunity

In the early 90s, the construction of a dam in the Upper Côa River was suspended in 1996 after the discovery of a great number of sites of rock art and the action of civil society that claimed the importance of conserving the site and saved the most important collection of Palaeolithic open-air art from being flooded. The great artistic and scientific value of the engravings led to the recognition by UNESCO as a World Heritage Site in 1998. Just one year later, the upper Côa and Massueime rivers were included in the Natura 2000 Network as a Special Protection Area, due to the importance of the river canyon for cliff-nesting birds, such as the Egyptian vulture (Neophron percnopterus), Black Stork (Ciconia nigra) or the Golden Eagle (Aquila chrysaetos). 

However, the obsolete walls today known as Foz Côa Cofferdams, which were part of the dam, remain, obstructing the connection between the Côa River and the Massueime Stream to the Douro River. The Foz Côa Cofferdams, along with other smaller barriers that are targeted by this project, are identified by the National Water Council as priority obsolete barriers to be removed and an aim in the Catchment Plan of Douro River. Removing these structures is both a symbol of the power of civil society and the recognition of the natural and cultural heritage of the Côa Valley. 

Project aims

The project aims to complete the last preparatory step needed to remove the two walls of Foz Côa Cofferdams. The technical, social, and environmental feasibility of the removal has already been assessed thanks to a prior programme grant, and viability studies have pointed out several ecological and cultural benefits of removing the barriers. Preparatory work involves elaborating Tender Specifications to open a Public Tendering Process for the removal. 

This project also aims to advance dam removal in Portugal, raise awareness of its need, and disseminate guidelines on replicating it in other catchments. Therefore, it will contribute to meeting national targets for the EU Restoration Law and the Water Framework Directive.