The Florence flood of November 4, 1966 is remembered as one of the most devastating natural disasters to hit Italy in the 20th century. The waters of the Arno River overflowed, submerging much of the city and causing enormous damage not only to people and infrastructure, but also to the artistic and cultural heritage of one of the most precious cities in the world.
The causes of the Flood
The flood of 1966 was the result of a combination of natural and structural factors that, together, led to a disaster of epic proportions. In the days leading up to November 4, Florence and Tuscany had been hit by exceptional rainfall. Torrential rainfall had saturated the ground, and river basins had filled to the breaking point. To make matters worse, there had been problems managing the water containment infrastructure. The reservoirs of the Arno and its tributaries, designed to regulate the flow of water, were not sufficient or adequately maintained to handle such heavy rainfall.
The Arno, a river historically known for its floods, was therefore in an emergency situation, and the drainage and containment system was completely overwhelmed. The combination of heavy rains, inadequate structures, and the natural conformation of the valley in which Florence is located, contributed to this disaster.
The Chronicle of the Flood
On November 4, 1966, in the early hours of the morning, the Arno began to overflow in several parts of the city. The first areas to be affected were those close to the river, such as the Santa Croce neighborhood and the Uffizi area. The water quickly poured into the streets, dragging with it everything in its path: cars, furniture, trees, and even buildings. The streets turned into raging rivers, and within a few hours the city was submerged by over 6 meters of water in some places.
Isolation was immediate. Telephone and electricity lines were cut, leaving much of the city without communications and power. Local and national authorities were unprepared to handle an event of this magnitude. Main roads were impassable, making it difficult for rescuers to reach them. Bridges over the river were at risk of collapse, with the water continuing to push forcefully against their structures.
The Consequences for the City
The damage caused by the flood was devastating. It is estimated that over 5,000 families were left homeless and 35 people lost their lives. However, in addition to the human damage, the flood caused an unprecedented cultural catastrophe. Florence, a city known for its artistic heritage, saw thousands of works of art damaged or completely destroyed. The National Central Library was among the places most affected, with 1.3 million volumes damaged or destroyed, including ancient manuscripts and books of inestimable value.
The mud and water that invaded museums and churches ruined frescoes, sculptures and paintings. Among the most serious damages was that of the Crucifix by Cimabue, located in the church of Santa Croce, which was seriously damaged by the water. The flood also hit the Uffizi Museum, the Ponte Vecchio and numerous historic buildings.
The “Mud Angels”
In response to the catastrophe, Florence saw an international mobilization of volunteers, known as the “Mud Angels”. Young people from all over Europe and the world came to the city to help recover and save damaged works of art. Armed with simple tools, such as shovels and buckets, they worked tirelessly to remove mud and water from museums, libraries and churches. Their work was essential to prevent even more serious damage to Florence’s cultural heritage. The “Mud Angels” became a symbol of international solidarity and their contribution was decisive in the attempt to recover what had been lost.
Post-Flood- Prevention Works
After the tragic flood of 1966, Italy realized the need to protect Florence and other cities vulnerable to similar events. For this reason, a series of hydraulic works were carried out to reduce the risk of future floods. Among the main infrastructures designed and built are:
1. Reservoirs and containment basins: One of the most important post-flood interventions was the construction of reservoirs and artificial basins along the course of the Arno and its tributaries. These basins were designed to retain excess water in the event of torrential rains, preventing the river from overflowing and causing another catastrophe.
A significant example is the Bilancino reservoir, completed in the 1990s, which can contain large quantities of water and regulate its flow.
2. Reinforcement of the banks: In addition to the creation of reservoirs, the banks of the Arno were reinforced, improving their ability to withstand the pressure of the flood waters. This intervention was essential to avoid future floods along the river.
3. Dams and flood control systems: Dams were built along the course of the Arno which, together with the containment basins, allow the flow of the river to be regulated during periods of heavy rain. These interventions proved crucial in preventing further natural disasters.
The effectsof these Interventions
One of the clearest proofs of this success occurred in 1992 and 1996, when heavy rains caused the level of the Arno to rise dangerously, but thanks to the reservoirs and containment basins, the river was able to hold without overflowing.
The Bilancino reservoir, with a capacity of over 69 million cubic meters of water, played a decisive role on these occasions. During particularly intense rain events, such as those of 1992, the reservoir was able to retain much of the excess water, reducing the pressure on the banks of Florence and preventing a new disaster. Other reservoirs along the course of the Arno, such as that of Levane, also contributed to keeping the flow of the river under control.
Furthermore, the Arno Project, a monitoring and management plan for the river’s waters that has been active for decades, has further improved the ability to predict and prevent critical situations. Today, Florence is considered safer thanks to a modern and well-designed water control system.