Preparing weir removals on the Vascão & Odeleite rivers

This project aims to scale up dam removals along the Odeleite River, as well as additional removals in the nearby Vascão River. These removals would help to build stronger relationships with local and national decision-makers for future removal projects.


The Algarve is the most Southern and driest region of Portugal. The Vascão River is part of a national Protected Area (Guadiana Valley) and is a Site of Community Importance (Natura 2000), and a Ramsar site, being considered the biggest river without artificial interruptions such as dams or reservoirs in Portugal. The Odeleite River is partially within Caldeirão SCI and not far from the same national Protected Area (Guadiana Valley) and a Ramsar site (Castro Marim salt marshes). The landscape is mostly characterized by Mediterranean scrubland and very low population density. Numerous archaeological remains from the Roman and Islamic periods are found in the area surrounding the Vascão River. Crucially, these two rivers host one of the few, remnant populations of the Spanish minnowcarp – the most endangered non-migratory fish species in Portuguese freshwaters, endemic to the Guadiana river basin – as well as other threatened fish species, the migratory European eel and sea lamprey, as well as several species of riparian birds, and iconic mammals such as the fish-eating otter and the endemic and endangered Iberian lynx.

At a glance

RiversVascão and Odeleite
Potential km to be opened up93
Focal speciesAnaecypris hispanica, Anguilla anguilla, Petromyzon marinus, Lutra lutra, Lynx pardinus
Project typeBarrier identification and prioritisation
Project statusLive

Project context and opportunity

Most of the barriers described in this project were prioritised for removal by a ministerial report and/or by the ICNF, the national authority for Nature and Forests Conservation. One of these barriers on the Vascão River was recently removed by the ICNF itself. Most (if not all) of these barriers appear to belong to the Municipality of Alcoutim, which is already partnering with ANP|WWF on the Galaxes weir removal.

This project is intended to significantly scale up the operations realised in Galexes Weir Removal project by aiming to remove two additional barriers in the same river (Odeleite River), and 12 weirs on the Vascão River – the two rivers that together host the only surviving populations in Portugal of the most endangered, non-migratory freshwater fish species, the Spanish minnowcarp (globally endangered).

These removals have the potential to restore 93 kms of free flowing river and significantly improve the habitat for – and therefore help conserve – the Spanish minnowcarp. The removals will also benefit the critically-endangered European eel and give a boost to other native species of conservation concern, including several fish species, as well as iconic mammals, such as the Iberian lynx and the otter.

Project aims

This project aims to scale up the single barrier removal targeted by the project Galaxes Weir Removal, preparing the path for further removals in the same river (Odeleite River), as well as additional removals in the nearby Vascão River. These removals would help to build stronger relationships with decision makers in the area and at national level and possibly gain commitments from them for future removal projects, both locally and nationally.

Overall, the project has the potential to restore the fluvial connectivity of more than 90 km of rivers, which would considerably contribute to the conservation of the endangered Spanish minnowcarp and the migratory European eel and Sea lamprey. The removals would also improve recreational activities in the area including fishing, hiking, and other traditional activities, which in turn would help developing tourism associated with the Natural Park of Guadiana Valley, as well as coastal tourist resorts in the Algarve. Also, by restoring the fluvial continuity, and in turn allowing ecological conditions for healthier fish populations, the removals would benefit local fishermen and the economy related to the consumption of freshwater fish, which are appreciated in local gastronomy.

The project will allow research visits to the barriers, confirmation of their owners, studies on the feasibility of removing all the barriers, meetings with local community and the Municipality of Alcoutim to discuss the removals, securing the necessary authorisations, contracting a construction company to prepare demolition and river design plans and provide invoice estimates, application for funding the removals, and efforts to secure co-funding from existing legislation or strategies.





Municipality of Alcoutim