The Malpasset Dam : the story
Always irrigation of the lowland of Fréjus (French Riviera) was a popularity issue for politicians. In the whirlwind of the Liberation, the elected representatives, dimmed by the frenzy of ambient reconstruction, wanted to follow the lead of the representatives of Marseille who have resolved their problems of water by constructing the Bimont dam near Aix-en-Provence.
Like its counterpart in the Bouches-du-Rhône, the General Council of Var called the trio of Bimont : Rural Engineering for the project management, the firm Coyne and Bellier for the design and Professor Georges Corroy from the Faculty of Marseille for the geological survey. Under the Rural Engineering control, Bimont was one of the few works executed without the fussy engineers of Electricité de France (EDF). The funding, mainly originating from the Marshall Plan, helped to build a huge concrete monument able to defy time and vagaries of nature.
Started later, the Malpasset project has not benefited from the Marshall Plan. Funding was provided by a grant from the Ministry of Agriculture and a bank loan. Annuities should be covered through the sale of water to surrounding municipalities. Saving cost was a significant factor in design and implementation of the dam.
The volume of concrete required for the construction of a dam is the frist determinant of price. The arch dam is the one which need less material. Choice was made to build a very thin arch dam, decision facilitated by the lack of road on the crest. The engineer, who never suffered setback,designed an ethereal structure with a volume of concrete significantly lower than comparable contemporary works.
This unfortunate dam has known bad luck on bad luck throughout his short life : military explosives in the area, materials unfit for concrete, labour disputes, severe drought, strong vibrations caused by blasting works for the construction of A8 motorway, resonance of the single valve and mostly undetected presence near the dam of multiple geological faults, including a very large one at the foot of the dam.
The dam still held 5 years. It even could hold a century without water... Break occurred exactly when the dam filled for the first time. A long bone of contention with Colonel Herbinger, the owner of spath-fluor mines located upstream from the dam has limited spot height significantly below the maximum during the first years of operation.
Monitoring was carried out by a single watchman, child of the region, hired on the spot for the occasion. Technically, no device was installed to monitor real-time movements of the dam. During all the years of operation, water for irrigation of the valley has not sunk. Canalizations provided for this purpose have never been completed.
Of all types of dams, the arch dam is the most intellectual one. It approaches perfection. It provides exceptional resistance as long as the terrain at the sides and bottom is very solid.
«Of all the made woks by hand of man, the dam is the most fatal» said the engineer in a prescient statement long before the era of nuclear power stations. It could have argued that in designing a civil engineering structure for which high security level is critical, degraded mode working has to be anticipated (a second engine on all airliners, watertight compartments in ships, ...). For the arch dam, the essential security factor in a hostile environment is the volume of concrete and significant strengthening of the anchoring support on sensitive areas.
At Malpasset the break was probably inevitable, but the instant disintegration of the dam could be avoided. Dam would have serious leaks, causing certainly a big flood, but the absence of the monstrous killer wave 40 meters high that swept through the quiet plain of Fréjus would have saved many lives.
On the 2nd of December, 1959 at 9:13 pm, the watchman witnesses the genesis of the drama helplessly. Living near the dam, he has no way, however, to raise the alarm. At the same time, a resident of the valley, addresses by phone a desperate call to the police station of Fréjus before disappearing into the wave. There is evidence that this call had no saving consequence. Twenty minutes later, without any warning procedure has been implemented, the wave height of about 10 meters swept low over Fréjus.
In the multitude of human tragedies that followed throughout this ominous night, many acts of individual bravery and small miracles have been seen : two carriages of the railcar Marseille-Nice were pulled out from the convoy and were swept away by the waves after the passengers had left its, on the initiative of the crew. They joined the engine carriage through windows after panes were smashed with an onboard hammer. A brave restaurateur used a pedalo
to save several people from drowning. Two families who lived in a old mill were saved after desperately blocking all exits of the building to prevent entry of water.
Young girl Viviane (11 years old) saved from drowning her two little brothers (2 and 9 years old), hoisting them up to the top of a wardrobe in their bedroom.
Malpasset drama is also the unprecedented mobilization of rescuers and donors. In her pain, the population of Fréjus received emergency resources out of the ordinary immediatly after the disaster. In full darkness, soldiers, marines of French and US navy and construction workers of A8 motorway quickly deployed an impressive logistics : helicopters, rescue boats, earthmoving equipment, trucks, bridges, etc. Doctors and nurses had been very busy all night, lighted by flashlights and without tap water, to treat the many wounded.
Early in the morning, radios relayed information and mobilization of donors was immediate and extremely important.
Fréjus received many donations from the most humble to the most fortunate. The influx of cash had never known equivalent.
By full cardboards, banknotes came to cover the tables installed by the town council in complete improvisation.
Trains and convoys of trucks brought in large quantities the most essential goods. From all over France and European countries, families offered to take in the many orphans.