Spanish Supreme Court to decide on Málaga WWTP

The Spanish Supreme Court will rule on the construction of Málaga’s largest wastewater treatment plant (WWTP), planned for the Vega de Mestanza near the city. Local residents opposed the project and successfully appealed, leading the High Court of Justice of Andalusia to halt construction shortly after it began in June 2025. The regional government has appealed to the Supreme Court and continues to support building the plant in the Guadalhorce valley. Since work was suspended, EU fines for failing to adequately treat wastewater have surpassed €1.1 million.

According to the newspaper Malaga Hoy, the controversial wastewater treatment plant (EDAR) in Málaga is designed to treat wastewater from five municipalities, namely Torremolinos, Cártama, Alhaurín el Grande, Alhaurín de la Torre, and part of the city of Málaga. The regional government insists on building this WWTP in the Vega de Mestanza. On 10 September 2025, the Andalusian government appealed to the Supreme Court. According to regional government sources, the court must now decide whether to admit the appeal and, if so, whether to uphold it.

Residents are convinced the battle has been won

The lawyer representing residents from the Mestanza and Lomas de Cantarranas association, Marcelino Abraira from Asturias, explains to the newspaper Malaga Hoy that the Supreme Court has no fixed deadline to take this initial step, but he does not expect a response until September or October, after the summer. In any case, he says he remains ‘calm’ and is convinced that the Supreme Court will not admit the regional government’s appeal and that the battle over the Vega de Mestanza ‘has already been won’.

Legal procedure

According to Abraira, attempting to have this court admit an appeal is a waste of time, unless there is a clear cassational interest, meaning that beyond the specific case, the matter has broader legal relevance. In his view, such relevance is ‘non-existent’ in this case. For that reason, he has already filed a brief requesting that the appeal be dismissed and has also requested documentation proving that the regional government submitted its appeal within the deadline, as he has serious doubts about whether it did so. In his opinion, the fact that the regional administration waited until the last day to appeal shows that even they are not convinced their appeal is strong. Nevertheless, Abraira states that if the Supreme Court admits the case and ultimately rules in favour of the regional government, he would take the matter to the Constitutional Court together with the residents of Vega de Mestanza. “I would have to comply with the ruling, but I would go to the Constitutional Court because I believe it would be a legal aberration,” he says.

Wastewater discharged in the Guadalhorce river

The regional government has been warning for years that without this major treatment plant, which involves an investment of €105 million, untreated wastewater from Alhaurín el Grande, Alhaurín de la Torre, Cártama, and Torremolinos, as well as part of Málaga city, representing a population of nearly 250,000 people, continues to be discharged into the Guadalhorce River. Currently, 5.9 cubic hectometres of untreated wastewater are discharged annually into the Guadalhorce River and, consequently, into the sea. This is equivalent to 1,750 Olympic swimming pools. This comes at a cost: Spain is fined by the European Court of Justice over wastewater deficiencies. As a result, Andalusia faces an annual fine of nearly €1.3 million (€634,000 every six months) for failing to comply with European Urban Wastewater Treatment Directive.

Flood-prone area

The location of the Northern WWTP in the Vega de Mestanza has been designated since 2003, and changing it would require another seven years of administrative procedures, according to the regional government. What residents oppose is precisely the installation of the plant in what is the last remaining fertile plain in Málaga, an area of high ecological value that is also flood-prone. As Mari Carmen Mestanza, a local resident and activist, points out in the local newspaper, the land has been flooded this winter at least four times due to the Guadalhorce River overflowing.