Torrevieja’s desalination plant: major investment and unexpected problems beneath the sea

Mussels, sand and other marine deposits have reduced the hydraulic capacity of the water intake pipeline at the Torrevieja desalination plant by approximately 17%. To address the problem, 900 metres of pipeline will have to be cleaned and around 63 tonnes of accumulated deposits removed. The additional technical work is estimated to cost approximately €1.58 million.

At first glance, this may seem like an unusual story about marine nature interfering with a modern engineering system. But behind it lies a much more important question: how reliable is the infrastructure on which water supplies for the population and agriculture of the southern part of Alicante province depend?

63 tonnes of marine deposits

The affected pipeline connects the water intake facilities at the western breakwater of Torrevieja port with the desalination plant. It is 2,280 metres long and has a diameter of 2.4 metres.

The most significant deposits have been detected along the initial section, which is approximately 900 metres long. In some places, mussels, sand and organic matter have formed a layer more than ten centimetres thick. Technical estimates indicate that around 63 tonnes of this material will have to be removed.

The problem is not limited to the reduction of free space inside the pipeline. The deposits make its inner surface rougher, increase resistance to water flow and force the pumping equipment to operate under additional strain.

Hydraulic tests carried out in April 2025 found flow resistance more than three and a half times higher than the theoretical level.

The planned measures include cleaning the pipeline, installing eight additional technical access points to facilitate operations and ventilation, and modernising the pumps. The direct budget for this additional work is approximately €1.58 million.

Almost €100 million and a revised deadline

This issue has emerged alongside a major expansion project at the desalination plant.

The project aims to increase annual production capacity from 80 million to 120 million cubic metres of water. In other words, capacity is expected to grow by 50%, adding another 40 million cubic metres per year.

This is a strategic facility for the region. Desalinated water enters the supply system of the Mancomunidad de los Canales del Taibilla and is also used for agricultural irrigation connected to the Tajo-Segura system.

However, the project has experienced delays. The expansion was originally scheduled for completion in February 2026. The new planned completion date for the construction work is 18 May 2027.

Following five modifications, the main contract is reported to stand at approximately €97.6 million.

It is important to understand that completing the construction does not mean that all the additional water volumes will immediately reach consumers. Testing and commissioning of the new capacity will still be required.

The issue is not just about mussels

This situation raises several legitimate questions.

Why has such a substantial accumulation of marine deposits required additional work during a major expansion project? How regularly was the intake system inspected? Were these risks taken into account when the facilities were designed and operated?

These are not accusations against the operators or project designers. The marine environment is complex, and biological deposits and corrosion are recognised technical challenges for this type of infrastructure. That is precisely why maintenance, inspection and prevention must be just as important as building new capacity.

When the main contract for infrastructure approaches €100 million, public interest goes beyond asking when construction will be completed. It is equally important to understand how reliable the system will be afterwards and what safeguards are in place to ensure continuous operation.

Water is a question of the Vega Baja’s future

For people living in the Vega Baja, water is not an abstract subject in technical reports. Its availability affects everyday life, businesses, agricultural production and the economic development of the area.

The Torrevieja desalination plant plays an important role in this system. Its expansion is intended to increase available water resources, but the expected outcome depends on more than the new reverse osmosis facilities. A properly functioning intake system, reliable pumps, regular maintenance and effective management of the entire system are also essential.

The Mediterranean Sea will not, of course, stop supplying water because of mussels. But turning seawater into a reliable resource for millions of consumers requires constant monitoring, engineering precision and responsible management of investment.

The main question, therefore, is not how many tonnes of deposits will have to be removed. It is whether the upgraded plant will deliver the promised increase in water production, how reliably it will operate and whether it will meet the region’s expectations.

Major investments create new opportunities. But the true value of infrastructure is not measured by the amount of money invested; it is measured by how reliably it serves people.