It was 10.39pm on 9 October 1963. Just at that moment around 260 million m³ of rock slipped into the artificial basin created by the Vajont dam, causing a flood wave over 200 meters high. And it was a tragedy, which went down in history as the Vajont disaster. Over 1900 deaths, entire countries erased from maps. And today exactly 62 years have passed since those tragic events.
A series of unfortunate circumstances meant that the enormous mass of rock fell at a speed of approximately 108 km per hour, ending up in the waters of the artificial hydroelectric basin of Vajont, which contained approximately 115 million m³ of water at the time of the disaster.
And the water from the dam went up the opposite side, destroying all the inhabited centers along the shores of the lake in the municipality of Erto and Casso, finally pouring into the Piave valley and dragging the town of Longarone and other neighboring municipalities into the mud. There were 1917 victims of which 1450 in Longarone, 109 in Codissago and Castellavazzo, 158 in Erto and Casso and 200 originating from other municipalities.
The Vajont tragedy has never been forgotten. But there are still many points that are not clarified, and if on the one hand the event is referred to as a natural disaster, on the other the superficiality of man is also called into question.
According to some studies, however, one of the worst hydrogeological disasters of the twentieth century has an ancient history. Research conducted by the geologist Edoardo Semenza, son of the designer of the Vajont dam, Carlo Semenza, has revealed something new regarding the Vajont.
The enormous boulder that detached from Monte Toc could have been the result of a paleolandslide, that is, a prehistoric landslide that detached itself thousands of years earlier, with an enormous volume accumulating in the valley and blocking the course of the Vajont torrent. Later, vegetation and erosion would hide it, making it appear to be part of the mountainside. However, the paleolandslide hypothesis formulated by Semenza was not taken into consideration by the geologists involved in the construction of the dam despite the numerous data collected in the field.
“The Vajont disaster constitutes the photograph of a short-sighted country from the point of view of prevention and valorisation of professionalism. The geologists of the time were unheard exactly as today, 55 years later, we continue to mistreat the territory and challenge the forces of nature with concrete and theoretical perfection, in accordance with the political approximation and arrogance of those who continue not to want to resolve the problem at its origins” are the words Domenico Angelone, Treasurer of the National Council of Geologists.
And today, while we remember that sad day, we realize that not much has changed. And we haven’t learned the lesson yet.
