Dam Failure Case Study: Val di Stava Dam (Italy, 1985)

On July 19, 1985, two mine tailings dams in northeastern Italy suddenly and catastrophically failed, killing 268 people and causing €133-150 million in damage. The two embankment dams were constructed in the 1960s as settling basins for waste from a nearby fluoride mine. The dams released approximately 180,000 cubic meters of tailings, burying the downstream villages of Stava and Tesero.

A combination of physical and human factors led to the collapse of the Val di Stava dams. Both dams were built with heterogenous and liquefiable materials, with the toe of the upper dam resting on the unconsolidated material of the lower basin. According to statements by the design engineer and company hands that worked on constructing the upper basin, the surrounding area was known to be swampy due to numerous springs. Similar hydrology conditions were present at the lower basin. Stability analyses performed during design and construction were inadequate, and warning signs were ignored, leading to the disastrous failure of the dams in 1985. In 1992, 10 people were found guilty of manslaughter for their respective roles in the failure and were sentenced to pay damages.