Since the early 2000s, the Portuguese energy matrix has been undergoing transformations brought on by policy changes, primarily investments in renewable energy sources. These alterations resulted in the adoption of energy efficiency measures and the use of indigenous renewable energy sources. Close to 30% of the total energy produced in Portugal is from hydroelectric dams. The greatest potential for hydroelectric power lies in the North of the country.


In an attempt to reduce its energy dependency, which currently corresponds to 80% of primary energy (imported), Portugal adopted a national energy strategy called “Estratégia Nacional para Energia” (ENE2020). ENE2020 has five main components: 1) an agenda for competitiveness, growth, and energy and financial autonomy; 2) investment in renewable energy sources; 3) the promotion of energy efficiency; 4) guarantees for the security of supply; and 5) economic and environmental sustainability (APREN, 2015). In parallel, the current management of existing resources is geared towards reducing greenhouse gas emissions by 2020 (LEITÃO, 2011).


The first large scale hydroelectric dams and reservoirs, primarily the ones in the Cavado and Tagus river basins, and the beginning of the exploitation of the Douro International dam date back to the 1950s. In the decades that followed, several thermal power stations began operating, introducing changes to the electricity generation system, which were stimulated by growth in consumption and the expansion of the energy grid throughout the country. It was only in the late 1980s that environmental concerns were integrated into the legislation through measures such as environmental impact assessments, which had immediate impacts on the pace with which this kind of project was approved. The 1990s were marked by the creation of a national energy system and the separation of the Rede Elétrica Nacional (REN, the national energy company) from Energias de Portugal (EDP). This left the management of the energy transmission network separate from power generation activities. Several companies in Portugal (including EDP, Iberdrola and Endesa) currently share this responsibility (VASCONCELOS, 2012).


Launched by the government in 2007, the National Programme of Dams with High Hydroelectric Potential (Programa Nacional de Barragens de Elevado Potencial Hidroelétrico, PNBEPH) emerged at a time when wind power was starting to supply an increasing amount of energy to Portugal’s energy grid. In fact, these projects proposed the construction of hydropower stations with reversible equipment to allow for hydroelectric pumping. This strategy would combine two types of energy: at times of low demand (generally at night or at dawn), the station pumps downstream water upstream using wind power, whose peak in production happens during the same period. Then, during the day and periods of high demand, water is released downstream again using turbines, which produces “cheaper” energy. This combination was claimed to be the solution for the lack of capacity to store surplus wind energy and was said to guarantee the viability of investing in these two types of projects at the same time. The PNBEPH contains plans to build 10 projects of this kind by 2020: 6 in the Douro river basin (Foz Tua; Padroselos; Alto Tâmega; Daivões; Fridão and Gouvães), 2 in the Tagus river basin (Almourol and Alvito), 1 in the Vouga basin (Pinhosão) and 1 in the Mondego basin (Girabolhos-Bogueira) (GEOTA, 2015).


Quercus calls attention to the cumulative effects of the dams in the PNBEPH, plus the hundreds of dams already built, on the sandy coastline. The impacts of the dams’ interference in the transport of sediments to the ocean has become increasingly evident in recent years, as it has resulted in a drastic reduction in sand and the erosion of the coast of Portugal. Between 2011 and 2017, the state has borne the cost of minimising coastal erosion by artificially replenishing the sand on the coast. It is estimated that in one decade alone, the amount spent on minimising coastal erosion will largely exceed the amount to be paid in compensation for the construction of these dams (QUERCUS, 2014).


GEOTA highlights that the target established by the programme, which has never been justified, was to increase the installed capacity of hydropower by 1,100 MW; existing capacity was at 5,900 MW. The programme does not establish targets for energy production and no alternatives to large dams were studied (GEOTA, 2015).


Of the locations defined by the PNBEPH, seven ended up being approved by the government. There were no candidates for the Almourol and Pinhosão projects. The Padroselos dam did not get approved, but the power it was to generate could be redistributed among the other dams. Currently, only six dams are scheduled to be built (the Alvito project was suspended by EDP) (GEOTA, 2015).


There have been significant delays in the implementation of the PNBEPH. The economic and financial crisis reduced the flow of credit and energy consumption fell, reducing the guaranteed revenues of the power generation companies. This made some of these projects much less attractive and profitable in comparison to 2007. Even so, thanks to the distortions that still exist in the energy market and the state subsidies that these works receive directly or indirectly, the works continue to advance.


Only the construction of the Foz-Tua dam on the Tua River, whose concession was granted to EDP, is at an advanced phase. Initiated in 2011, the works on the dam were scheduled to be finished by August 2017 (LUSA, 2017).


It was announced that the construction of the three dams in the Tâmega river basin would begin in 2015. Together, the Gouvães, Alto Tâmega/Vidago and Daivões dams form the Tâmega hydroelectric power complex (or the Sistema Eletroprodutor do Tâmega, SET, in Portuguese). The concession for these works was granted to Iberdrola.


The contract for the construction of the Fridão dam, the fourth new dam on the Tâmega river, downstream from the SET, was to be signed with EDP in September 2014, but that did not happen. There is still no official date for the works to begin. The Girabolhos-Bogueira dams (Mondego River), whose concession was awarded to Endesa, are advancing more rapidly: expropriations are underway, roads are being built and the construction site is being set up (GEOTA, 2015).


The 12 new large-scale dams (10 from the PNBEPH plus Baixo Sabor and Ribeiradio-Ermida) will have a capacity of 1,343 MW and an average annual output of electricity of 2.1 TWh/year. This corresponds to 4.3% of the total production of electricity and 0.8% of the total energy demand in Portugal in 2012, and 3.2% of the economically attractive energy-saving potential (GEOTA, 2015).


The strategic environmental assessment carried out for this plan was criticised because of several flaws, namely the failure to study its cumulative impacts. These include: 1) the increase in risks for riverside communities; 2) the accumulated degradation of river habitats resulting from the operation of various dams in the same basin, namely the Tagus and Douro basins and the Tâmega sub-basin; and 3) the additional risk of coastal erosion. Thirty percent of the Portuguese coast is threatened by erosion and one of the causes of this is the retention of sediments by the new dams (MELO, 2009).


There are two sides to the debate on the government’s plans to build new dams: the “barragista” or pro-dam side and the “green” side. The “barragistas” argue in favour of the construction of the dams, pointing to the growing demand for water and the need to produce more energy to respond to the increase in consumption generated by economic and social development and demographic growth. The “green” side opposes the construction process, as it fails to respect the pillars of sustainability: social, economic, environmental and, in the case of the dams, landscape (DUARTE, 2013).


In view of the diverging arguments, the entire process of implementing the plan has been met with strong objections from environmentalist organisations, scholars and civic movements, among others. The main motives for this opposition are: disregard for public participation in the decision-making process; failure to recognise the cultural and environmental values of the locations of the dams; and the irrelevance of these projects to the country’s energy independence.


The most emblematic cases that existed prior to the PNBEPH are the Baixo Sabor dam (2004) and the Foz Côa dam (1991). In the case of the former, the mobilisation of non-governmental organisations, environmentalist and other institutions and individuals that came together in the Free the Sabor River Coalition (Plataforma Sabor Livre, PSL) established a new form of organising resistance. Protests and other tactics were used, such as the filing of a complaint with the European Commission and the boycott of the EDP Fund for Biodiversity. However, despite the irregularities identified, these actions were not enough to halt the construction of the dam. What makes this case so important were the motives for opposing it, which the movements claimed were not only environmental: “what makes Baixo Sabor different is the discrepancy between the enormous negative impacts for the country and the scarce benefits it will generate, when better alternatives exist” (MELO et al., 2010). Despite all this, the construction of the Baixo Sabor dam was concluded in August 2014.


The case of the Foz Côa dam, on the other hand, constitutes a victory on not only environmental, but also heritage and cultural issues. With the support of political parties and national and international conservation organisations, the local population mobilised against the dam and succeeded in halting its construction, thus preserving the world heritage in question.


The media played a decisive role in drawing the national and international communities’ attention to the Foz Côa case. It caused the spread of political and cultural manifestations that generated: slogans, music and clothing, petitions, camps and student movements, the sale of wine products, study tours, art exhibitions, posters, post cards and stickers, art sales, music concerts, etc. (ALMEIDA, 1996).


As for the Foz Tua dam, also situated in the Alto Douro wine region, which was declared a world heritage site by the United Nations Educational, Scientific and Cultural Organization (UNESCO) in 2001, the construction process is at an advanced phase. Founded in 2013, the Plataforma Salvar o Tua (PST, or the Save Tua Coalition) obtained international recognition for the legal actions it has undertaken, as well as its numerous public awareness campaigns and artistic-cultural projects. In 2015, this coalition was the topic of debate in the Assembly of the Republic due to its petition entitled the “Manifest for the Vale do Tua” – the third one to be presented to the parliament on this matter. The manifest, which is still available online and has over 7,300 signatures, was debated on January 8. That day, supporters of the petition staged a silent protest in the Assembly’s plenary, where the proposal to suspend the works on the Foz Tua dam was voted down by the PSD, CDS and PS parties (PST, 2015).


In early 2016, the government announced it would revise the PNBEPH to honour the agreement reached in November 2015 between the PS, BE, PCP and PEV parties to establish a left-wing majority in the parliament. The PNBEPH originally included plans to build seven dams: Foz-Tua (Tua River), Fridão, Alto Tâmega/Vidago, Daivões (Tagus River), Gouvães (Louredo River), Girabolhos (Mondego River), and Alvito (Ocreza River), and the government announced that based on the results of the revision of the PNBEPH, it decided to maintain the plans to build only four dams: Foz Tua, Alto Tâmega/Vidago, Daivões  and Gouvães. Authorities cancelled the Girabolhos and Alvito dam projects and postponed the decision on the Fridão dam (Tagus River) for three years (GEOTA-RIOS LIVRES, 2016; CABRITA-MENDES, 2016). Furthermore the government decided to demolish the obsolete dams and reservoirs witch allow waterways to return to their natural course (LUSA, 2016).


Even though NGOs such as Zero and Quercus welcome this decision, they defend that none of the four dams should be built and the suspension of the construction of Foz-Tua dam, even if it is at an advanced stage. They suggest that the government pay the fines for rescinding the contracts and eliminate all subsidies to the sector (DN, 2016).


Grupo de Estudos de Ordenamento do Território e Ambiente (Geota) and Liga Para a Proteção da Natureza (LPN) published a lengthy statement where they directly criticise the government’s decision. They argue that:

- the municipalities and the environmentalist and local development organisations did not have the opportunity to discuss the report and that the government only negotiated with the power companies;

- the government’s affirmation that the works had already begun on the dams that are to be part of the Tâmega hydroelectric power complex (on the Daivões, Gouvães and Alto Tâmega rivers) is false, as a study by Rios Livres/Geota on the status of the works reveals;

- due to the postponement of the decision on the Fridão dam, the people of Amarante and Terras de Basto must face another three years of uncertainty and the impossibility of using the land in the area that could be occupied by the future reservoir;

- the cumulative impacts of the dams on the fauna, flora and vegetation of the Tâmega valley were not taken into account. These include: the degradation of water quality, obstacles to connections between ecosystems, coastal erosion and changes to the microclimate, which will affect wine production;

- it authorises EDP and Iberdrola to extract 10.4 billion euros from families in Portugal – in other words, it triples the tariff deficit and imposes an additional cost of 2,600 euros on every family, which is the equivalent of an average increase of 5% of the electricity bill (GEOTA; LPN, 2016).


Besides these conflicts that earned greater visibility, the Ribeiradio-Ermida dam on the Vouga River and the Gouvães, Padroselos, Alto Tâmega and Daivões projects have also sparked conflicts that involve non-governmental organisations, the population’s participation in protests, petitions and shows of support from certain political parties.


Intense conflicts have also arisen in recent years over plans for mini hydropower plants, referred to as such because of their capacity of 10 MW or lower. These include the Penacova and Poiares Hydropower Project (Aproveitamento Hidroelétrico de Penacova e Poiares, AHPP) on the Mondego River and the two mini hydropower plants on the Paiva River and its tributary, the Paivô River. They are considered successful cases of environmental protest, as their construction was suspended. Through their mobilisations, institutions and the population proved that the projects were unjustifiable in economic terms and would cause irreversible environmental damage.


In January 2017, the government proposed eliminating a subsidy that all consumers pay directly to large corporations when they pay their electricity bill. Through the so-called “interruptibility” subsidy, every year, close to 50 large companies are paid a total of 112 million euros in exchange for their commitment to reduce their energy consumption when the risk of overloading the power system arises. The creation of this subsidy was justified as a way of guaranteeing the security of the residential energy supply and avoiding power outages.


Since the Energy Services Regulatory Authority (ERSE for its acronym in Portuguese) regulated interruptibility several years ago, through Resolution no. 192 from July 29, 2010, these companies have yet to be ordered to reduce their consumption. Even so, oddly enough, they receive this benefit on a regular basis. A working group of representatives from the BE and the PS was created with the mandate to reduce the number of companies with interruptibility contracts and save consumers close to 60 million euros (BRITO, 2017). According to a study released recently by Jornal de Negócios, EDP is the most valuable Portuguese company.


In the meantime, EDP announced plans to begin producing solar power in November 2017 in Trás-os-Montes on the Alto Rabagão dam. It is the first pilot project in Europe to combine the generation of hydroelectric and solar power. The structure consists of 840 solar panels mounted on a 2,500 m2 floating platform. Elaborated in 2015, the project is currently undergoing analyses on its technical and economic feasibility before being tested on other dams and/or exported to other countries. EDP’s director explained that floating solar parks gained momentum in the aftermath of the Fukushima disaster in Japan and that they are more compact than the ones built on land, occupy less space and produce the same levels of energy (BRITO, 2017).


On February 16, 2017, Geota filed a complaint with the Attorney General’s Office on suspicion of corruption and influence peddling in the construction of the Tâmega, Tua and Sabor dams (SIC, 2017).



Bibliographical references


ALMEIDA, Henrique. Arqueologia vs desenvolvimento? Sobre as margens de um rio que ecoa. Máthesis, v. 5, p. 213-235, 1996.


APREN. Estratégia nacional para a energia 2020, APREN-Associação de Energias Renováveis, 2015.


CABRITA-MENDES, André. Cancelamento das barragens da EDP e da Endesa tem "custos zero para os cidadãos". Negócios. 19 abr. 2016.

DN. Grandes barragens: decisão do Governo não chega, dizem as ONG. Diário de Notícias-DN. 18 abr. 2016.


DUARTE, A. F. N. S. Barragens e albufeiras em Portugal. Usos da água, preocupações ambientais e ordenamento do território. Caso de estudo: Albufeira de Foz Tua., Dissertação de mestrado em gestão do território na Faculdade de Ciências Sociais e Humanas da Universidade Nova de Lisboa, set. 2013.


GEOTA. O Programa Nacional de Barragens: desastre económico, social e ambiental – Memorando. site do Grupo de Estudos de Ordenamento do Território e Ambiente-GEOTA, versão de jul. 2015.


GEOTA. Luz verde para as barragens no Tâmega resulta em 10.000M€ tirados às famílias portuguesas. Comunicado conjunto GEOTA-LPN, 21 abr. 2016.


GEOTA. O último ano do Tua. Rios livres-GEOTA. Acedido em: 18 jun. 2016.


LEITÃO, António E. As energias renováveis. Estratégia nacional para o desenvolvimento das mini–hídricas intenções e realidade. Encontro Nacional de Engenharia Civil, 21 mai. 2011.


LUSA. Associação Zero aplaude intenção de demolição de barragens obsoletas. Público. 16 mar. 2016a.


LUSA. Quercus defende eliminação de barragens e reabilitação da vegetação junto aos rios. Sapo24. 2 jun. 2016b.


MELO, João Joanaz de. Public works policy in Portugal: a case study in unsustainability. Lusíada International Journal of Engineering and Industrial Management, n. 1, p. 195-208. 2009.


MELO, João Joanaz de; CHAINHO , P.; FRÁGUAS, B.; SANTOS, P.T.; PATACHO, D. A barragem do Baixo Sabor: um caso de má aplicação da avaliação de impactes ambientais. Resumo das comunicações em CD da 4ª Conferência Nacional de Avaliação de Impactes, Vila Real, 20-22 out. 2010.


PST. Petição – “Manifesto pelo Vale do Tua”: resumo dos acontecimentos, PST-Plataforma Salvar o Tua, 2015.


VASCONCELOS, Tiago. Análise técnico-económica de um aproveitamento hidroelétrico: aproveitamento hidroelétrico do Baixo Sabor. Dissertação de mestrado em Engenharia Eletrotécnica e de Computadores, Instituto Superior Técnico, 2012.


June 30, 2017.


Since the time that the first hydroelectric dam was inaugurated in Portugal in the 1950s until now, the history of hydroelectricity has been marked by both technological changes and the country’s economic and social development. Growth in consumption and electrification gave rise to environmental concerns that began to be integrated into the legislation in the 1980s. The 1990s was marked by the creation of a national energy system and the separation of the Rede Elétrica Nacional (REN, the national energy company) from Energias de Portugal (EDP). At the dawn of the 21st century, the production model began to combine renewable energy sources such as wind and solar power with the goal of contributing to the reduction of greenhouse gas emissions.

Who asked for a national dams programme anyway?

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