Malaga plans to separate sewage and rainwater pipelines to minimise discharges into the sea

The mixture of rainwater and sewage reached the sea and forced the introduction of bathing restrictions on some beaches due to pollution.

The storm (this time a political one) was inevitable and the local ruling team faced a barrage of criticism for the lack of separate drainage systems.

The city's water authorities addressed these complaints on Thursday, with a presentation by councillor for the environment Penélope Gómez and managing director of public water company Emasa Juan Denis.

"We are upgrading the network to ensure that rainwater does not mix with wastewater," they stated.

The urban planning department and Emasa are now collaborating to improve the system, which will cost nearly 50 million euros.

The aim is to protect the urban coastline against increasingly intense rainfall, which is becoming more sporadic and violent as a consequence of global warming.

The plan is to complete around 20 infrastructure projects aimed at expanding the separate sewerage network and minimising the discharge of waste into the sea.

This allocation forms part of the 2024-2029 water infrastructure investment plan, with a budget of over 100 million.

The challenge is considerable: events such as that of 15 August, when 14mm fell in one hour, generate peak flows of up to 200,000 cubic metres, which overwhelm the standard treatment capacity of the sewage treatment works.

Malaga is good at managing its stormwater thanks to the planning regulations introduced under the 1983 general urban development plan (PGOU). Currently, 58 per cent of the city has a separate drainage system, in areas such as Teatinos, Churriana, the western part of Cruz del Humilladero and the northern section of the Este district, pipes separate from those carrying sewage channel rainwater.

The system in areas such as El Limonar, Miraflores del Palo and Puerto de la Torre is combined. It mainly discharges into storm drains, although they retain small sections of combined sewers.

The main problem lies with the remaining 24 per cent of the combined network: Centro, Bailén-Miraflores, Cruz del Humilladero and Carretera de Cádiz. In dry weather, these function as combined sewers, but during torrential downpours, authorised emergency spillways prevent flooding on public roads.

To reduce the environmental impact of these rainwater discharges and retain bulk sediment, the plan prioritises four strategic areas. First, the separation of networks, notably the tender for the Dos Hermanas stormwater channel and works currently under way in areas such as La Malagueta, Las Flores, Pedregalejo Alto and Salvador Allende.

Second, overflow treatment facilities and stormwater tanks, including the construction of the large anti-pollution stormwater tank on the Carretería collector (Guadalmedina) and the installation of new screens at spillways and sewage treatment works.

In addition to this, there are other measures aimed at improving the transport of wastewater to treatment works, including the refurbishment of pumping stations (EBAR Campo de Golf, San Julián, Moby-Dick), and the replacement of the Sacaba-Guadalhorce pipeline.

The city council has also allocated funding for controlled marine discharge (1.9 million) to extend and upgrade the Jaboneros and Pacífico submarine outfalls.

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