A Visit to Frejus to Understand the Malpasset Dam Tragedy
Located just a few kilometres from the French Riviera coast and the city of Frejus are the striking remains of the Malpasset Dam. This river barrier, completed in 1954, was a substantial post-war infrastructure project. However, the structure failed on the night of December 2, 1959, less than five years after completion.
“De tous les ouvrages construits de main d’homme, les barrages sont les plus meurtriers”. (“Of all the works of mankind, dams are the most murderous.”)
A quote by international dam expert and engineer André Coyne, who was assigned to oversee the dam’s construction, in 1952 (before completion).
The Malpasset Dam was arched in design, or more technically (for the engineering types) a double curvature with a variable radius. This dam on the Reyan River reached a total height of 66 meters with a thickness of 6.78 meters at the centre of the foundation. It is a universal design for dam projects.
The goal for controlling the River’s flow was to satisfy the irrigation needs for agricultural lands surrounding Frejus. The requirement for a dam was undisputed. The Reyan River was notoriously dry in summer months and a raging, flooding menace during the winter rainy season. Studies began as early as 1865 for a barrier on the river upstream from the Malpasset site.
The history of this dam is a bit unclear as some reports have the construction work starting in 1941. However, World War II and labour strikes undoubtedly disrupted any early work. Post-war, this infrastructure project was one of many approved by the French state as part of the aménagement du territoire (land use planning). Geological and hydrological studies were undertaken in 1949. Although, there is some question as to the quality of the engineering studies, due to lack of proper funding. Construction work at the site of the dam commenced in April 1952. The final cost of the project, in 1955 dollars, was 580 million francs. The statistics are below:
The Force of Water
A breach in the structure occurred on December 2, 1959, at precisely 21:13. The concrete dam fortification collapsed, releasing a wall of water (a dam break wave) the was 40 meters in height. When the wave reached Frejus, seven kilometres down the valley and about 20 minutes later, the water was still three meters high. The water arrived with such a force it even pushed several military aircraft into the Mediterranean. The villages of Malpasset and Bozon were utterly destroyed in the water’s wake. The adjacent highway construction site, several small roads and railway tracks were all ruined, cutting the Côte d’Azur train access off from the rest of France for a period.
The official count of the number of people killed varies but the most consistent number is 423 dead.
Was it poor design? Damage caused by the nearby roadworks? Earthquake tremors? Or the relatively (to other dams) a thin foundation?
Watch this documentary video on the project and the theories about the dam failure.
The investigations determined it was most likely the foundation and the rapid rise in the volume of water in the weeks before the accident. According to records or rumour, there were cracking noises observed but not investigated, and the right side of the dam experienced some leaks in November 1959. Also, there were heavy rains before the failure, raising the water level by some 4-5 meters; this may have been a contributing factor to the breach. Experts in the engineering field still maintain that the design of the dam was appropriate and would be much the same today. The photos below are what remains at the dam site today.
Lest we forget – a sobering reminder at the entry to the park:
Riviera Reporter: The Malpasset Dam Disaster – could the Var suffer again?
On The Failure of Malpasset Dam by Richard E.Goodman Consultant and Prof. Emeritus of Geol. Eng, Univ. Cal., Berkeley
La Catastrophe de Malpasset en 1959 by Frank Bruel