A chance discovery during metro line construction is set to transform a Barcelona-adjacent city into a unique metropolitan wellness destination. Santa Coloma de Gramenet plans to harness a naturally heated underground aquifer to create a large-scale public spa, with waters reaching nearly 30 degrees Celsius, all accessible via a short metro ride from the Catalan capital.
The ambitious scheme, dubbed ‘Santa Coloma, ciudad termal’ (Santa Coloma, thermal city), stemmed from a serendipitous find back in 2014. Engineers working on the extension of Barcelona’s Metro Line 9 uncovered a significant hot water aquifer hundreds of metres beneath the city. Subsequent studies confirmed the resource’s stability and sufficient flow, ensuring no impact on local drinking water supplies, as 20 Minutos reported. Consequently, the city council is now progressing with plans to transform this geological gift into a major public asset.
A Wellness Hub in Can Zam Park
The proposed thermal centre will form a cornerstone of the redevelopment of Parc de Can Zam, one of Santa Coloma’s largest green spaces. The project envisions a 10,000-square-metre facility for daily public use. Plans include a mix of indoor and outdoor swimming pools at various temperatures, along with hydromassage areas, jet circuits, saunas, and relaxation zones, creating a comprehensive wellness epicentre.
The Ajuntament de Santa Coloma de Gramenet’s vision is twofold. Firstly, it aims to establish a public spa offering new leisure and wellbeing services to residents across the Barcelona metropolitan area. Secondly, the project incorporates a strong sustainability focus. Additionally, the thermal water will supply a district heating network, providing hot water to municipal facilities such as sports centres and schools, thereby reducing energy consumption and costs. This energy efficiency focus aligns with broader regional goals, exemplified by Endesa’s recent major investment in the nearby Sant Adrià power plant.
Connectivity and a New ‘Thermal’ Identity
The project’s viability hinges on its direct connection to Barcelona. Located just a short walk from a Line 9 metro station, the spa will be less than 20 minutes from central Barcelona. This seamless public transport link is crucial for attracting visitors from across the region. While the metro forms the lifeblood of the metropolitan area, connecting millions daily, its smooth operation faces constant challenges, as a stray dog recently halted service on another line for two hours.
During the project’s initial presentation, then-mayor Núria Parlón envisioned Santa Coloma becoming a “pioneer in family thermalism” and a “benchmark for energy efficiency in Europe.” Its potential is significant; geological assessments indicate the aquifer is vast, spanning over 50 hectares beneath the city’s Fondo, Santa Rosa, Latino, and Can Mariner neighbourhoods. Experts consider the resource comparable in quality and abundance to renowned Catalan spa towns like Caldes de Malavella or Caldes de Montbui.
This development forms part of a broader effort by the Àrea Metropolitana de Barcelona (AMB) to enhance quality of life and public services across its municipalities. This encompasses recent investments in adding more electric buses to the transport fleet and promoting sustainable mobility via initiatives such as a major new cycling strategy.
Project on the Horizon
While the vision is clear, construction of the spa has not yet begun. The project is currently in its technical and administrative definition phase. The city council anticipates the public tendering process for selecting a design and construction firm will commence in 2026. This investment is viewed not merely for its economic return, but as a long-term contribution to the city’s urban transformation, providing new services and boosting local activity.
If realised, the Can Zam thermal spa will offer a unique proposition: a natural hot spring retreat seamlessly integrated into the urban fabric, accessible not by a long country drive, but by a simple tap of a T-mobilitat card.
