In January 2008, the vast pit left by the As Pontes lignite mine in Galicia began a carefully managed change. Over four years, engineers filled the site with 547 million cubic meters of water, equivalent to 547 billion liters. The result is now one of Europe’s largest artificial lakes. By April 2012, the lake had reached a stable level. Its shoreline ranks among Spain’s top beaches, and the beach is set to retain Blue Flag status in 2026.
The As Pontes mine operated from the 1970s until late 2007, supplying lignite to a nearby power plant. Regional authorities say more than 261 million tons of lignite were extracted during its final three decades, while nearly 700 million cubic meters of overburden were moved. Mining left behind a massive void and an extensive external spoil heap, both in need of impressive environmental rehabilitation.
From Extraction to Restoration
Restoration began well before the last excavators left. In the 1980s, Endesa, the company operating the mine, launched a program to stabilize soils and restore topsoil, then planted grass, shrubs and trees. By 2006, revegetation of the spoil heap was complete, paving the way for the next phase: turning the mine pit into a lake.
Engineering a New Field
Filling the pit was a complex process. In 2005, environmental authorities approved a plan to combine runoff and nearby streams with water diverted from the Eume River. A basic canal nearly six kilometers long, together with additional channels, carried water into the basin. The project also included a natural outflow to the Carracedo River, helping the lake maintain water quality and avoid stagnation.
Simply letting the pit fill naturally was not an option. The plan called for strict controls to prevent acidity, including six reed-filled wetlands and a lime-based neutralization system, alongside revegetation of the slopes. Authorities closely monitored water chemistry and slope stability, as well as potential contamination. By 2012, the lake had reached its planned volume. Since then, it has operated with controlled inflow and overflow.
Two Worlds Below the Surface
Despite the scale of the restoration, the lake’s waters remain stratified. Scientific studies have identified two distinct layers, separated by a chemical boundary. The upper layer is oxygenated and slightly acidic, while the deeper zone is more acidic and lacks oxygen. This separation limits mixing and preserves different chemical conditions at various depths. So, only surface waters are suitable for swimming and recreation, a distinction reflected in the Blue Flag assessment criteria.
From Industrial Past to Public Space
The public beach at As Pontes opened in 2012, with 400 meters of coarse sand and sheltered swimming areas. The surrounding field features shallow zones and islands, as well as artificial cascades designed to support aquatic life. Endesa reports that the restored area now covers 1,200 hectares, including meadows and shrubland alongside forest and ponds. It supports more than 239 vertebrate species. The change has reconnected the site with the local community, providing space for recreation and water sports, along with environmental education.
The lake is an artificial freshwater body occupying the former open-cast lignite mine in A Coruña province. Its beach has a designated bathing area. Sailing and kayaking are among the activities available in the surrounding leisure zone, which also offers windsurfing, information from Ventosurf’s listing for Lago das Pontes. A defined swimming area and separate water-sports uses give the former mine a continuing role as a managed public amenity.
Today, the lake draws people for kayaking and sailing, with windsurfing and other aquatic activities also available. Retaining Blue Flag status depends on meeting strict environmental and safety standards. The project offers a rare example of a post-industrial field repurposed for public benefit while preserving its history.
The environmental legacy of decades of mining cannot be fully erased, but the As Pontes lake shows what planned restoration can achieve. For visitors to Galicia, the site brings together natural beauty and recreation, while offering a glimpse into the region’s industrial past.
The transition in As Pontes also extends beyond the lake. The Tesouro wind project has a planned capacity of 50.4 megawatts and is to be paired with Tesouro Storage, a 17.5-megawatt battery system. Spain’s Directorate-General for Energy Policy and Mines granted Enel Green Power España, an Endesa group company, prior administrative and construction authorization for the battery installation. It is designed to operate alongside the wind farm. The authorization was published in Spain’s Official State Gazette.
La Voz de Galicia reported that the Tesouro project formed part of Endesa’s response to capacity lost after the As Pontes thermal plant closed, and that project procedures were at an advanced stage. The development puts the lake within a wider industrial and energy transition in the former mining area, where renewable generation is being developed alongside storage and the site’s recreational use.
The Xunta de Galicia has also presented the region as a strategic location for a new industrial and energy economy. In an October 2026 statement, Pablo Fernández Vila, the Xunta’s director general for Energy Planning and Mines, described the goal for the mining sector as a “modern, sustainable and competitive” model developed with private-sector participation. This policy context shows that As Pontes is being reshaped as part of a continuing regional transition, beyond its completed restoration.
Decades of mining have left an environmental legacy that cannot be fully erased, but the As Pontes lake shows what restoration planned from the outset can achieve. For visitors to Galicia, the site offers natural beauty and recreation, as well as a glimpse into the region’s industrial past.
