Vajont Dam

Vajont Dam
Vajont Dam in 2002
Location of Vajont Dam in Italy
Official nameItalian: Diga del Vajont
LocationItaly
Coordinates46°16′02″N 12°19′44″E / 46.26722°N 12.32889°E / 46.26722; 12.32889
Construction began1956
Designed byCarlo Semenza
Owner(s)ENEL
Operator(s)SADE – Società Adriatica di Elettricità (today part of Edison)
Dam and spillways
Type of damConcrete double curvature arch dam
ImpoundsVajont River
Height262 metres (860 ft)
Length160 metres (520 ft) (chord)
Width (crest)3.40 metres (11.2 ft).
Width (base)27 metres (89 ft)
Reservoir
CreatesLago del Vajont
Total capacity168,715 thousand cubic metres (5,958,100×10^3 cu ft)
Power Station
Turbines4

The Vajont Dam or Vaiont Dam is a disused hydro-electric dam in northern Italy. It is one of the tallest dams in the world, with a height of 262 m (860 ft). It is in the valley of the Vajont (river) under Monte Toc, in the municipality of Erto e Casso, 100 km (62 mi) north of Venice.

The dam was conceived in the 1920s and eventually built between 1957 and 1960 by Società Adriatica di Elettricità, at the time the electricity supply and distribution monopoly in northeastern Italy. The engineer was Carlo Semenza (1893–1961). In 1962, the dam was nationalized and came under the control of ENEL as part of the Italian Ministry of Public Works.

On 9 October 1963, during initial filling of the lake, a landslide caused a megatsunami in which 50,000,000 m3 (1.8×109 cu ft) of water overtopped the dam in a wave of 250 m (820 ft), bringing massive flooding and destruction to the Piave Valley below, destroying several villages and towns, causing an estimated 1,900 to 2,500 deaths. The dam itself remained almost intact and two-thirds of the water was retained behind it.

This event occurred after ENEL and the Italian government concealed reports and dismissed evidence that Monte Toc, on the southern side of the lake, was geologically unstable. They had disregarded numerous warnings, danger signals, and negative appraisals. Underestimating the size of the landslide, ENEL's attempt to safely mitigate any landslide by lowering the level of the lake came too late, when disaster was almost imminent.