Tarragona, Spain: sustainable water management through energy optimissation

SUEZ helped CAT optimise pumping operations in real time. The project shows how digital solutions can support more sustainable, efficient and resilient water infrastructure management.

Between 2005 and 2012, CAT electricity cost more than doubled, rising from €2 million to €5 million (pumping was the main source of energy demand), in a context of increasing energy price volatility and growing integration of intermittent renewable energy sources such as wind power.

Spanish and European regulations are driving the energy transition and greenhouse gas emission reductions, requiring infrastructure adaptation and greater integration of renewable energy throughout the water production and transport process. At the same time, local climate vulnerability, including risks of drought and increasing pressure on water resources, highlights the need for more sustainable and efficient water management solutions.

In this context, SUEZ deployed the Aquadvanced water supply solution to optimise pumping operations in real time. The system adjusts water production and transport strategies according to electricity tariffs while selecting the least energy-intensive sources and distribution routes. This optimisation enabled the Consorci d’Aigües de Tarragona to reduce its bills by around 15%, representing nearly 700 000€ in savings per year and more than 1 million euros saved over three years of operation.

The solution also relies on a hydraulic digital twin that continuously monitors and optimises network operations. In addition, since 2024, it has supported the integration of solar energy into the network’s energy mix and contributed to CAT’s objective of increasing the share of alternative energy sources in its electricity consumption.

The Tarragona region faces increasing pressure on water resources, driven by highly variable rainfall patterns and more frequent drought episodes. In Catalonia, reservoir levels have recently reached critical thresholds, in some cases falling below 30% of their total capacity, placing significant strain on water supply for both domestic and industrial uses.

In this context, ensuring consistent water quality and reliable service has become a major challenge for public health and economic continuity. Controlling water service costs is also essential to limit the impact of these constraints on users.

The project helps improve service reliability and water quality through the deployment of the Aquadvanced water supply solution. The system optimises pump rotation and reservoir level management, reducing the risk of water quality deterioration while ensuring a more stable service for users.

CAT is a public, non-profit water consortium bringing together municipalities, public authorities and major water users to serve a population of around 800,000 people. It operates under a non-profit model so efficiencies generated by Aquadvanced water supply can be reinvested for improved service, tariff stability, and in the long-term resilience and security of the water supply.