Andalusian High Court deals another blow to Guadalhorce river wastewater treatment plant and overturns expropriations

The future of the largest water infrastructure project currently under construction in Andalucía looks increasingly bleak. While Spain's Supreme Court decides whether to admit appeal the Andalusian regional government (Junta) lodged after last June's ruling that annulled the project, the High Court of Justice of Andalucía (TSJA) has now also struck down the expropriations in a separate judgment.

The court fully upheld the appeal the Mestanza and Lomas de Cantarranas residents' association lodged against the wastewater treatment plant through their lawyer Marcelino Abraira.

The Andalusian high court declared void the regional government's administrative decision to begin preliminary proceedings for the urgent occupation of land and rights affected by the compulsory purchase process linked to construction of the wastewater treatment plant.

Judge Manuel López Agulló, who drafted the ruling, based the decision on the fact that the courts had already annulled the main legal measure supporting the expropriations.

The ruling recalls that the same chamber had ruled on 16 June 2025 in favour of the same residents' association, overturning and fully cancelling both the treatment plant project and its preliminary plans. Since the original legal basis no longer stands, the TSJA ruled that the related expropriation process must also fall.

The ruling revisits the legal arguments that led to the collapse of the treatment plant project. It states that the Junta chose Vega de Mestanza solely on economic grounds, considering it the cheapest option because of the shorter pipeline network required and the lower expropriation costs compared with other proposed sites.

However, the court found that the regional authorities breached environmental assessment law by failing to carry out a rigorous environmental study of the alternative locations. The ruling stresses that the affected area forms part of the World Biological Corridor.

The ruling also states that the authorities dismissed the alternative sites purely for financial reasons and only carried out an environmental assessment after selecting the location. As a result, the environmental impact report became little more than a procedural formality intended to justify a decision already made.

Because the court fully upheld the residents' appeal, it also ordered the regional government to pay legal costs, capped at 2,000 euros plus IVA tax. The authorities can still lodge a cassation appeal within 30 working days, either before the Supreme Court or the TSJA.

Spain's Supreme Court now effectively holds the future of Malaga's Edar Norte wastewater treatment plant in itshands. It must decide whether to hear the Junta's appeal against the TSJA ruling, which sided with residents from Vega de Mestanza and Lomas de Cantarranas in their campaign against the plant.

The Edar Norte is currently the largest hydraulic infrastructure contract awarded in Andalucía, worth 104 million euros.

Meanwhile, the EU continues imposing fines over wastewater discharges into the Guadalhorce river. Those penalties have already reached ten million euros, including the first half of 2026. It is taxpayers who pay this bill. Plans for the facility date back around 20 years.

Work on the project remains suspended. The TSJA ruling did not directly force construction to stop, but the Andalusian regional government decided last summer to halt the costly project because of the legal uncertainty surrounding it.

The Edar Norte wastewater treatment plant would process wastewater from Alhaurín de la Torre, Alhaurín el Grande, Cártama and new residential development areas in Malaga city.

The project should not be confused with Malaga city's main Guadalhorce treatment plant, which also handles wastewater from Torremolinos, or with the Bajo Guadalhorce plant, already operational and serving Coín and Pizarra.

Malaga's municipal water company Emasa manages the first facility and charges third parties for the service, while the provincial water consortium runs the second. In theory, Emasa would also manage the future Guadalhorce plant, although the final legal structure still depends on the outcome of the court proceedings.

Authorities awarded the contract for the future plant in late 2021 to the Aquambiente-Dinotec-Sando consortium, with a planned construction period of 36 months. The project aimed to phase construction work and deploy additional teams to tackle first the wastewater discharges that triggered EU sanctions.

So far, the technical improvements the Junta introduced have done little to rescue the scheme. Those changes included reducing the plant's physical footprint by 34 per cent, improving tertiary treatment systems, relocating sludge treatment outside the selected site and allowing future expansion without requiring more land.

The future of this key infrastructure project now looks highly uncertain. If authorities must find a new site and restart the entire approval process from scratch, EU fines will keep rising for at least another five years.

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