Power blackout shows vulnerability Spanish water supply

Spain’s power grid is tightly interwoven with its essential services, and the power blackout of 28 April showed just how vulnerable they are to disruption. The country’s water supply is critically dependent on electricity. While emergency systems can offer temporary relief, a sustained power outage has the potential to collapse the entire water cycle. This in turn puts public health at serious risk.

During the blackout, some residents across Spain experienced significant drops in water pressure, while others faced near-total service cuts. In metropolitan Barcelona, supply failures were reported in high-lying areas just below the Collserola range, particularly between the Llobregat and Besòs rivers. Aigües de Barcelona confirmed that water service was disrupted in neighbourhoods at the city’s highest elevations due to pump failures. Backup generators can buy time, but only a few hours or days at the most. Once fuel supplies run out, the water stops flowing.

Failing water pumps

The first systems to fail in a prolonged outage would be water collection stations. Without electricity, groundwater pumps and surface water extraction points cease. Water treatment plants would quickly run out of raw water to purify. Even if some reserves remain in tanks, the shutdown of filtration, sedimentation, and chlorination processes would prevent safe water delivery. The distribution network would also buckle under pressure, or rather, from the lack of it. Pumps that maintain flow through the primary and secondary networks would fail, especially impacting higher floors of buildings, homes reliant on rooftop tanks, and elevated neighbourhoods. As pressure drops, the risk of external contaminants entering the system increases.

Desalination plants shut down

After the power blackout electrical failures at the Carboneras desalination plant in Almería caused major disruptions. The authorities are speeding up measures to restore the water supply to 140,000 residents of Almería. They emphasize restoring the drinking water supply is one of the most urgent matters now. The total blackout impacted a significant percentage of the population in the province of Almería. Also, the desalination plant of Campo de Dalias shut down by the power blackout and left Roquetas del Mar without drinking water. Hidralia started the desalination process again when the power came back on, but it took 5 to 6 hours to get the plant operational. The drinking water service was restored in the afternoon of April 29.

Panic-buying bottled water

Concern over the water supply led to widespread panic-buying of bottled water and other basic provisions in the afternoon and evening of 28 April. Reports from several major cities, including Valencia, Zaragoza, Madrid and Seville, noted supermarkets in affected areas were experiencing long queues and empty shelves. Bottled water was one of the most sought-after items. Some shops placed temporary limits on purchases per customer as fears grew over how long the disruption would last.

Vulnerability

Until now, there is no news the collapse of wastewater treatment plants (WWTPs or EDARs), but of course they have been affected as well by the power blackouts. Yesterday’s blackout made clear the complex water-energy nexus is very strong. The power blackout was long enough to expose a vital vulnerability in Spain’s water infrastructure.