Definition
Vajont is the name of a valley, river, and associated hydro‑electric dam in the Friuli‑Venezia Giulia region of northern Italy, best known for the Vajont Dam (also spelled Vaiont Dam) and the catastrophic landslide‑induced flood that occurred on 9 October 1963.
Overview
The Vajont Dam (Italian: Diga del Vajont) is a concrete double‑curvature arch dam located in the municipality of Erto e Casso, about 100 km north of Venice. Constructed between 1957 and 1960 by the Società Adriatica di Elettricità (SADE) and later operated by ENEL, it stands 262 m (860 ft) high, making it one of the tallest dams in the world. While the dam itself remained largely intact, the filling of its reservoir, Lago del Vajont, triggered a massive landslide from the northern flank of Monte Toc. The displaced rock mass entered the reservoir, generating a megatsunami that overtopped the dam by roughly 250 m (820 ft), destroying the downstream towns of Longarone, Erto, Casso and others, and causing an estimated 1,900–2,500 deaths.
Etymology / Origin
The name “Vajont” derives from the Vajont River, which flows through the gorge where the dam was built. The river’s name is of local origin, likely rooted in the Ladin or Friulian languages historically spoken in the Alpine valleys of the region. The term does not have a broader meaning outside this geographical context.
Characteristics
| Feature | Details |
|---|---|
| Location | Vajont valley, under Monte Toc, Erto e Casso, Friuli‑Venezia Giulia, Italy (coordinates 46°16′02″ N 12°19′44″ E) |
| Dam type | Concrete double‑curvature thin‑arch (gravity‑arch) |
| Height | 262 m (860 ft) |
| Crest length | 160 m (520 ft) |
| Crest width | 3.40 m (11.2 ft) |
| Base width | 27 m (89 ft) |
| Reservoir capacity | 168.7 million m³ (≈ 5.96 billion ft³) |
| Power plant | 4 turbines, originally intended for hydro‑electric generation |
| Construction period | 1956 – 1960 (operational 1960 – 1963) |
| Key event | 9 Oct 1963 landslide (≈ 800 000 m³ of rock) → megatsunami → overtopping and downstream flood |
| Current status | Disused; the dam remains standing but the reservoir is no longer filled for power generation. The site is a memorial and a subject of engineering and geological study. |
Related Topics
- Vajont Dam disaster – The 1963 landslide‑induced flood, a landmark case in dam safety and geological risk assessment.
- Monte Toc – The mountain whose unstable northern slope collapsed into the reservoir.
- Hydraulic engineering – Studies of dam design, especially arch dams, and the importance of geotechnical investigations.
- Landslide‑generated waves (megatsunamis) – The phenomenon illustrated by the Vajont event.
- ENEL – The Italian state electricity company that operated the dam after nationalization.
- Longarone – The town most heavily destroyed by the flood; later rebuilt.
- Dam safety regulations – International standards that were revised in part due to lessons from the Vajont catastrophe.
All information is drawn from established encyclopedic sources, including the Wikipedia entry on the Vajont Dam and the Encyclopaedia Britannica article on the Vaiont Dam.