Thousands of Spanish municipalities are sidestepping national and regional laws that forbid building in high-risk flood areas. As a result, many communities continue building in flood-prone areas, leaving over a million people at risk across Spain, from Murcia to Barcelona, Valencia, and Valladolid.
Experts are calling for more robust regulations to ensure that all municipalities update their urban development plans (PGOU) every 12 years at the most. Jorge Olcina, a professor at the University of Alicante, emphasised, “When a zone is at high flood risk, construction should not be permitted.” However, with most plans dating back decades, they remain disconnected from newer safety laws that came into force in 2008.
One million people at risk in Spain
According to a recent study by the Sustainability Observatory, over one million residents live in areas categorised as high or medium flood risk. Some of the highest-risk areas include Murcia, with 320,000 residents, and Catalonia, with 161,000 people, mostly in Barcelona. Despite the clear danger, urban development continues unchecked. Fernando Prieto, the director of the Sustainability Observatory, stated bluntly, “Flood risk maps are not being followed, and developers are ignoring them while mayors look the other way.”
Calls for radical change
Several experts suggest relocating entire neighbouhoods or towns to safer areas, a drastic but potentially life-saving measure. This approach has been seen before, following the tragic flood of Tous in 1982. At this time, the towns of Gavarda and Beneixida were relocated after being submerged. The hope is that future recovery efforts, such as rebuilding after the recent DANA storm in Valencia, will prioritise safety by relocating residents instead of simply rebuilding in risky areas.
Climate risk management plans
Cristina García, professor Economy at the Complutense University in Madrid comments in El Mundo on the recent catastrophic DANA that has devastated parts of Valencia. She emphasises this is far from the first major flood to impact the province. Reflecting on whether this tragedy could have been prevented, she believes that, to a large extent, it could have been. “We already have projects and risk management plans in place, especially those focused on climate change adaptation,” García states. She points to the National Climate Change Adaptation Plans, which include preventive measures, such as climate impact assessments on Spain’s water resources and targeted projects.
Urban development in the wrong areas
Asked whether construction has taken place in areas where it should not have, García is unequivocal: “Yes, absolutely. Much of this massive urban development has occurred in areas that should never have been built on.” She points to homes, roundabouts, and ring roads built on dry riverbeds, river courses, and adjacent areas that should have been left clear. In regions like Murcia, Valencia, and Almería, flood-prone areas have been developed. Expanding agricultural and industrial activities has increased sediment runoff. This also contributes to flooding, as farming is taking place in flood-prone areas, often with irrigation systems.
“We haven´t allowed the water an escape route”
Moreover, García highlights the issue of soil impermeability. “Most urban expansion has not occurred on permeable soil,” she explains. In countries like the UK or the Netherlands, which experience heavy rainfall, urban spaces have long been developed using permeable surfaces. Examples are pavements that allow water to filter through during heavy rains, reaching basins and aquifers. “The problem here is that we haven’t allowed the water an escape route,” García adds. “We need urban development with permeable surfaces that allow water to filter through and reach its natural outlets. The water will always find a way out.”
From typical cold front to an extreme, brutal event
In addition, she points out that climate change is exacerbating these issues, altering natural weather patterns. “What used to be a typical cold front in Valencia is now an extreme, brutal event,” she remarks. This is happening across the Mediterranean and is beginning to affect the Atlantic, as both are warming. Despite national adaptation plans in Spain, these torrential rains have become more frequent and more intense.