Spain’s recent episodes of intense rainfall have exposed critical weaknesses in urban infrastructure, particularly the sewage systems designed to manage wastewater during heavy storms. The overwhelming volume of water has caused numerous sewage treatment plants to exceed their capacity, resulting in untreated or partially treated sewage being discharged directly into rivers and coastal waters. This surge not only threatens aquatic ecosystems but also poses significant public health risks, as contaminants and pathogens spread through recreational and fishing areas.

Authorities are now facing urgent calls to upgrade drainage networks and invest in resilient water management solutions. The impact of these disruptions can be summarized as follows:

  • Environmental degradation: Increased nutrient loads lead to algal blooms and oxygen depletion.
  • Water contamination: Pathogens and…