Effects - Large dams risk
Large dams may be affected by intense natural events (such as rainfall, landslides, earthquakes, etc.) or structural problems.
Some events, such as heavy and prolonged rainfall, may require the activation of spillway operations: these are common scenarios that are part of the ordinary management of the reservoir. Other events, such as large landslides or structural damage, may affect the safety of all or part of the structure; these are rare situations but of considerable impact.
In both cases, flooding of downstream areas bordering the watercourse may occur. Such flooding can vary in severity: it is generally more rapid and intense in areas near the dam and becomes less severe as one moves further away.
Following the introduction of legislation concerning safety measures in facilities in the 1920s, catastrophic events in the territories downstream of dams have become increasingly rare in our country. The last significant event was in 1963, involving the Vajont dam at the border between Friuli-Venezia Giulia and Veneto.