Spain's Tungsten Mine Threatens Portugal's Water Supply and Border Communities

The Portuguese Parliament has once again pressed Environment and Energy Minister Graça Carvalho for clarity on a contentious tungsten mine across the border in Galicia—a project that could affect water supplies, protected nature zones, and the legal standing of cross-border environmental protocols. The Socialist bench submitted a formal inquiry last Friday, demanding updates on whether Madrid has finally responded to Lisbon's diplomatic overtures and whether Portugal will have any say in the environmental review of a mine slated to begin operations in the second half of 2026.

Why This Matters

• Water risk: The San Juan tungsten mine sits 100 meters from a stream that feeds the Rabaçal River, a drinking-water source for villages in Vinhais.

• Legal vacuum: Spain has not formally notified Portugal under the Espoo Convention or the 2008 bilateral protocol, despite the mine's proximity—less than 2 km from Portuguese territory.

• Strategic status: The Swedish operator Eurobattery Minerals is seeking European Strategic Project designation, which could fast-track approvals and sideline normal environmental safeguards.

A mine on the doorstep—and silence from Madrid

Tucked into the hills of A Gudiña, in Ourense province, the San Juan concession covers deposits estimated at 60,000 tonnes of tungsten ore with a grade of 1.3% WO₃; other sources cite reserves as high as one million tonnes. Eurobattery Minerals, which acquired a 51% stake in the exploitation rights, broke ground in October 2025 and expects to ship the first concentrate by mid-2026 under a supply contract with an Austrian buyer.

The mine's footprint extends uncomfortably close to the Montesinho Natural Park and the Meseta Ibérica Transfrontier Biosphere Reserve, both of which rely on stable hydrology and minimal industrial intrusion. Environmentalists and municipal leaders in Vinhais warn that runoff from open-pit operations—particularly heavy metals and processing reagents—could leach into the Pente stream, which drains directly into the Rabaçal and ultimately the Tua and Douro river systems.

Yet as of early April 2026, Lisbon has received no formal notification from Spanish authorities. In a November 2025 reply to an earlier parliamentary question, Minister Carvalho confirmed that the Portuguese Environment Agency (APA) had sent a letter to Madrid requesting information and expressing interest in joining the environmental‑impact‑assessment process. Portugal's embassy followed up with a diplomatic note asking for timelines. Neither has yielded a public answer.

What the law requires—and where Spain may be failing

Under the 1991 Espoo Convention, ratified by both Portugal and Spain, any State planning a project with potential cross-border environmental effects must notify affected neighbors at an early stage and invite them into the scoping and review process. The two Iberian neighbors reinforced that obligation with a bilateral protocol signed in February 2008, which sets out step‑by‑step procedures for transboundary consultations on plans, programmes, and projects.

EU law mirrors these commitments. The Environmental Impact Assessment Directive (2011/92/EU, as amended by 2014/52/EU) obliges Member States to assess, notify, and consult on projects that may have significant effects beyond national borders. Mining operations—especially those involving hazardous substances or located near protected areas—fall squarely within the directive's Annex I and II lists.

Legal experts and environmental groups point out that the original 2015 environmental declaration for San Juan expired in 2019 and cannot lawfully justify the 30‑year extension or the higher extraction volumes now planned. In March 2026 a court in Santiago de Compostela opened a criminal investigation into alleged malfeasance by Galicia's Director-General of Energy Planning and Mines and a senior executive at Eurobattery, on the grounds that the extension was granted without a fresh impact study. Separate proceedings in Ourense will examine alleged environmental infractions at the site itself.

Impact on residents and protected landscapes

For people living along Portugal's northeastern frontier, the stakes are immediate and tangible. The Rabaçal River supplies drinking water to hamlets including Pinheiro Novo and Quirás. A pollution event—whether a tailings-pond breach or chronic seepage of arsenic, lead, or tungsten compounds—could render those intakes unsafe and force costly alternative supplies.

Beyond public health, the mine threatens the ecological integrity of Montesinho, a 75,000‑hectare park that anchors nature tourism, wolf conservation, and traditional agro‑pastoral livelihoods. Noise, dust, and blasting vibrations from the quarry face carry across the ridge line; landscape scarring and deforestation upstream ripple through the biosphere reserve. Local advocacy groups, notably the UIVO movement based in Vinhais, have been vocal in opposing the project and calling on both governments to enforce transboundary safeguards.

Tourism operators worry that the "green and pristine" branding of the Montesinho–Meseta Ibérica corridor will erode if visitors perceive the area as industrialized. Property values in border villages could also stagnate if water‑quality concerns become entrenched.

Strategic-project gambit and environmental NGO pushback

Eurobattery Minerals has applied to Brussels for recognition as a European Strategic Project under the Critical Raw Materials Act, which aims to secure supply chains for the energy transition. Tungsten is classified as a critical material because of its use in electric‑vehicle batteries, aerospace alloys, and hard‑metal tooling. Strategic status confers streamlined permitting, access to EU co‑financing, and—critics warn—reduced scrutiny of environmental and social risks.

Several environmental NGOs have already submitted reservations to the European Commission, arguing that fast‑tracking a mine with unresolved cross‑border impacts would set a dangerous precedent and undermine the legal architecture of the Espoo Convention and the EIA Directive. They contend that strategic designation should not exempt a developer from mandatory transboundary consultation.

What Parliament wants to know

In the fresh round of questions tabled on 11 April, eight Socialist deputies—led by Pedro Vaz, Júlia Rodrigues, and André Pinotes Batista—ask Minister Carvalho:

Whether any reply has arrived from Spain following APA's letter and the embassy's note, and if so, what it says.

Whether Portugal has been formally notified or consulted under the environmental‑impact‑assessment procedure; if not, whether the Government considers Spain to be in breach of international and EU obligations.

Whether Lisbon learned through Commission channels of the strategic‑project application, and whether it intends to lodge an objection.

The deputies underscore that their parliamentary group has been tracking the file since November 2025 and that the lack of transparency remains troubling. They note that the Left Bloc has also pressed the Government on the matter in separate interventions.

The broader context: cross‑border mining friction

The San Juan controversy is not an isolated episode. In recent years Portugal and Spain have sparred over uranium exploration near Salamanca, lithium concessions in northern Portugal that could affect the Spanish reach of the Douro basin, and hydroelectric projects along shared rivers. Environmental advocates criticize the Albufeira Convention—the 1998 framework for managing Iberian river basins—as opaque and outdated, ill‑suited to address cumulative industrial pressures on transboundary water.

At the same time, both governments have committed to scaling up domestic production of battery metals and rare earths to meet EU climate targets. Spain is channeling investment into critical‑raw‑materials projects, while Portugal has licensed lithium exploration in several northern municipalities despite local resistance. The tension between green‑transition imperatives and local environmental protection is acute, and legal mechanisms designed to balance those interests—consultations, impact assessments, public hearings—are being tested.

What happens next

Barring a court injunction in Spain or a formal objection from Brussels, Eurobattery Minerals appears on track to commission the San Juan mine within months. Metallurgical test work is under way to finalize processing flowsheets, and the company has stated publicly that all necessary licenses and contracts are in place.

For Portugal, the window to influence the project's design—tailings management, water‑discharge limits, real‑time monitoring, emergency‑response protocols—is narrowing. If Madrid continues to stonewall, Lisbon could escalate the dispute to the Espoo Convention's Implementation Committee or file an infringement complaint with the European Commission. Either route takes time, and by the time a ruling comes down the mine may already be operating.

Residents in Vinhais, meanwhile, are left watching bulldozers move earth on the Spanish side of the ridge and hoping that diplomatic channels will deliver the protections that treaties promise on paper. Whether those promises translate into enforceable safeguards—or remain polite letters filed in embassy drawers—will become clear in the coming weeks.