Acosol hires Ayesa for desalination

Acosol, the public water company for Spain’s western Costa del Sol, has awarded Ayesa Ingeniería y Arquitectura the contract to draft the preliminary design for a second seawater desalination plant, local media reported on May 15. The work covers the future plant for the Costa del Sol Occidental, a stretch of coastline that has faced repeated pressure on water supply in drought years. The award moves the project from political backing and tendering into technical definition of where the plant could go and how large it should be. Acosol launched the tender in December 2025 with a budget of 1,074,170.41 euros including VAT and a maximum execution period of 24 months. ### What exactly has Ayesa been hired to deliver? The December 5, 2025 tender notice said the contract includes three stages: a needs study, an alternatives study and the preliminary design itself. Acosol said that package is intended to produce the technical documents needed for a later joint tender covering the construction project and the works. (elespanol.com) The same Acosol notice said the assignment also includes documentation for environmental, sectoral and urban-planning authorizations, the delimitation of land required for the project and technical material to support expropriation proceedings if those become necessary. Diario SUR reported that the document entrusted to Ayesa will define, among other things, plant capacities and possible locations. (acosol.es) ### Which decisions are likely to come first? Diario SUR reported that the preliminary design will set out capacities and locations, putting the first focus on siting and configuration choices rather than construction itself. That typically means the early comparison of alternatives for seawater intake, brine outfall, land availability and how the plant would connect to the regional water network, based on the scope described by Acosol. (acosol.es) Acosol’s tender documents, as summarized in its December notice, also require the contractor to prepare the groundwork for permits and land definition. Those requirements mean the study phase will have to address environmental and urban-planning constraints before the project can move to a build tender. ### Why is the Costa del Sol pursuing a second desalination plant now? (diariosur.es) Marbella’s existing desalination plant completed the second phase of its expansion on May 31, 2025, lifting capacity to 20 million cubic metres a year, according to Sur in English. The same report said the population served needs about 90 million cubic metres a year, leaving desalination as only part of the broader supply system. (acosol.es) Acosol said in December that the new plant is intended to add supply and help guarantee drinking water for the comarca. Manuel Cardeña, president of the Mancomunidad de Municipios de la Costa del Sol Occidental, said at the time that the region wanted to prepare the infrastructure needed to face future drought episodes, while Acosol chief executive Matilde Mancha said the plant would reinforce supply in an area with high population density and tourism. (surinenglish.com) ### Is Mijas still central to the plan? A January 13, 2025 meeting in Mijas tied the municipality closely to the project’s early political backing. Acosol and the Mancomunidad said then that they were committed to developing the preliminary design for the second desalination plant in Mijas and would first seek financing from Acuamed, the state-owned water infrastructure company. (acosol.es) Ana Mata, the mayor of Mijas, said after that meeting that the different administrations needed to be involved to guarantee water resources for the municipality. The newer reporting on the Ayesa award refers to defining locations, which indicates that the exact site still has to be tested through the alternatives work rather than treated as settled. (revistalugardeencuentro.com) ### What has to happen before construction can be tendered? Acuamed appears in Acosol’s planning as the next institutional checkpoint. Acosol said its technicians worked with Acuamed on the tender documents and that, once the preliminary design and supporting documentation are completed, the package will be handed to Acuamed for study and assessment before the project and works are tendered in coordination with the Junta de Andalucía. (revistalugardeencuentro.com) The contract timetable points to a long preparation phase rather than an immediate start on site. Acosol’s December notice set a maximum execution period of 24 months for the design work, and local reports on the May 15 award say Ayesa is now the company charged with producing the document that will define capacities and locations for the future plant. (acosol.es)