Galaxes Weir, Portugal

Increasing fish abundance and biodiversity in the surrounding area and restore fluvial connectivity. This was the first civil removal of an obsolete river barrier in Portugal, and will improve habitat conditions of endangered fish species.

Introduction

The Algarve is the most Southern and driest region of Portugal. The Odeleite stream is partially within Caldeirão SCI and not far from a national Protected Area (Guadiana Valley) and a Ramsar site (Castro Marim salt marshes). The landscape surrounding the Galaxes Weir is mostly characterized by Mediterranean scrubland and very low population density. The river hosts one of the few populations of the Spanish minnowcarp (Anaecypris hispanica) – the most endangered non-migratory fish species in Portuguese freshwaters, endemic to the Guadiana river basin – and other threatened fish species (Squalius alburnoides, Leuciscus pyrenaicus, Salaria fluviatilis, etc.), possibly including the migratory eel (Anguilla anguilla), as well as several species of riparian birds, and mammals such as the fish-eating otter (Lutra lutra) and the endemic and endangered Iberian lynx (Lynx pardinus).

At a glance

Project typeDam removal (demolition)
Project statusComplete
Removal dateMarch - July 2023
CountryPortugal
RiverOdeleite
Km opened7.7
Focal speciesAnaecypris hispanica, Anguilla anguilla, Lutra lutra, Lynx pardinus
WebsiteANP WWF

Project context and opportunity

The National Authority for Nature and Forests Conservation (ICNF), identified the Galaxes Weir as one of the obsolete barriers to be removed to improve fish and overall biodiversity in the area and restore fluvial connectivity (Bochechas 2014).

This was the first civil removal of an obsolete river barrier in Portugal, and it is expected to improve the habitat conditions of endangered fish species. This project is also expected to result in several other removals in the catchment, as well as in other catchments, boosting the dam removal movement in Portugal. Recently, another barrier in another stream nearby (Vascão stream), which also hosts the Spanish minnowcarp, was removed by the ICNF.

Project aims

The project restored the fluvial connectivity of 7.7 km of river, thus constituting a good step towards conserving the endangered Spanish minnowcarp and the critically endangered eel. Also, by restoring the fluvial continuity and, in turn, allowing ecological conditions for healthier fish populations, the removal will benefit local fishermen and the economy related to the consumption of freshwater fish, which are appreciated in local gastronomy.

The removal is expected to improve recreational activities in the area, including fishing, hiking, and other traditional activities. The project will help develop tourism associated with the nearby Natural Park of Guadiana Valley and coastal tourist resorts in the Algarve.

Project achievements

The Galaxes Dam was removed on March 27, 2023, in partnership with the Alcoutim City Council, and not only restored connectivity along 7.7 km of Ribeira de Odeleite (Guadiana River basin) but also contributed to the conservation of several species of fish (and others that cohabit the same space), which thus already have space to reproduce.

Partners

ANP WWF

Alcoutim