Sau reservoir through drought: From empty basin to submerging 11th-century church

The historic years-long drought that hit Catalonia heavily necessitated water use limits across the territory, restricting many industries and sectors. During this period, the Sau reservoir in central Catalonia has been seen as one of the most impactful symbols of the water crisis.

In early 2024, the iconic reservoir was less than 5% full, but now, recent rains have filled the basin up past 72% of its total capacity, leaving the famous Sant Romà de Sau church almost fully submerged.

Normally, this 11th-century Romanesque church has little architectural or historical value apart from its strange location and setting, as it is almost entirely submerged when water levels are high.

For years, with the drought getting worse and worse, that was not the case, with more elements of the tower becoming visible, and other buildings that remain of the historic town also coming to light. Now, however, the church is almost completely under water again for the first time in four years.

In early 2024, especially in March, Catalonia suffered the worst period of the drought episode. At the time, the Catalan government moved the Ter-Llobregat water system into an ‘emergency’ drought phase, affecting over six million inhabitants – the vast majority of people who live in Catalonia. The emergency level was recently lowered to the pre-alert phase after the Sau reservoir surpassed 64% of its capacity.

The Sau reservoir is just a snapshot of the overall situation, as many reservoirs across Catalonia have registered peaks of water capacity. The largest reservoir in the internal basins area, Susqueda, has doubled its reserves from 20.8% to 43%.

Drought restrictions lifted

The drought restrictions ended on Friday after the Catalan government approved the lifting of such limits on Tuesday.

This change allows more water to be used for agricultural irrigation, environmental flows, and in urban uses.

Despite more rains falling in recent months, desalination plants will continue operating at their higher 90% capacity, and investments to combat the drought will be maintained despite the improving picture.