Spain is facing a quiet but serious infrastructure challenge: around one third of state-owned dams require immediate structural reinforcement, while half of the facilities have faulty drainage systems – a critical weakness in the face of increasingly volatile weather conditions and rising rainfall events across the country.
Spain Press Editorial Team
by Marlon Gallego Bosbach
Ageing concrete giants facing new risks
Many of the most strategically important dams on the Iberian Peninsula date back to the 1950s and 1960s. They were built at a time when engineering standards and environmental requirements were very different. After more than six decades in operation, these massive structures are not only ageing – in many cases they are considered structurally weakened and technologically outdated.
According to current analyses, 112 of Spain’s 375 state-owned dams urgently require reinforcement of their structural fabric. Without these measures, there is not only an increased risk to the functionality of the facilities, but also to the safety of people and infrastructure in the surrounding reservoir areas.
Half of the infrastructure with faulty drainage systems
Particularly alarming is the fact that more than half of the dams (50 %) have faulty “desagües de fondo” – the bottom outlets through which water can be controlled and released when necessary.
These technical components are crucial for controlling floods, relieving structural pressure, or quickly and safely releasing water during extreme rainfall. If they do not function properly, the risk of overloading or uncontrolled water discharge increases – scenarios that could have far-reaching consequences for downstream areas.
Lack of emergency plans and safety assessments
But the problems are not only technical: three out of four state-owned dams have no implemented emergency plans – meaning there are no practical strategies for evacuation, warning, or coordinated response in the event of a hazard. Likewise, most of the facilities lack up-to-date, comprehensive safety and risk assessments.
Without these organisational foundations, valuable time could be lost in an emergency – a situation experts refer to as a “systemic safety deficit.”
Policy lagging behind – lack of funding hinders modernisation
The engineering association Asociación Caminos criticises the political and financial framework: Spain would need to invest around 700 million euros annually in the maintenance of its dams to achieve a modern level of safety. In reality, however, only a fraction of this amount – just under 16 million euros – has been allocated in recent years.
This massive investment backlog has resulted in structural measures and technical modernisations being postponed long-term or carried out only in a minimal form – a development that is increasingly criticised in light of recurring extreme weather events.
Smaller dams: the true scale unknown
The situation is even more opaque and often more worrying for smaller reservoirs that are not under state management. Municipalities, irrigation associations, and private operators frequently struggle with limited resources, poor maintenance, and a lack of technical monitoring. Many of these facilities are considered neglected or are only rudimentarily supervised.
Severe weather as a risk amplifier
The current debate over dam safety comes at a time when Spain is once again experiencing unstable weather and heavy rainfall. Extreme precipitation increases the pressure on reservoirs and underscores the importance of functioning drainage systems and effective emergency measures.
Experts warn that without urgent structural, technical, and organisational measures, the risk of damage to the facilities and potential threats to the population will increase significantly.
