Vaiont

Vaiont, also known as Vajont, is a valley in the Veneto region of northern Italy, in the province of Belluno, near Longarone. It is best known for the Vajont Dam on the Piave River and the 1963 disaster.

The dam, a concrete gravity dam built by SADE, was constructed in the late 1950s and completed in 1963 at the head of the Vaiont valley. It created a large reservoir behind a steeply sloping rock face of Monte Toc, with one of the tallest dams in Europe at the time.

On October 9, 1963, a massive landslide from Monte Toc entered the reservoir, displacing a large amount of water. The resulting wave overtopped the dam and caused widespread flooding in the Piave valley, destroying villages such as Longarone and causing the deaths of about 2,000–2,500 people. The dam itself did not collapse.

The disaster prompted investigations and reforms in dam safety, geology, and risk assessment. It highlighted the need for thorough geotechnical evaluation, monitoring, and clear hazard zoning around large reservoirs. Legal actions were brought against officials and engineers. The Vajont Dam remained in service after safety adjustments and continues to generate electricity, while the site is marked by memorials.

The event has become a reference case in engineering ethics and disaster studies, illustrating the consequences of underestimated geological risk. The Vaiont region remains associated with the Vajont disaster, which is documented in museums and memorials in the area.