Design flood estimation: lessons learnt from sella zerbino dam-break

Abstract

In 1925 two dams were constructed across the Orba River to store water in Ortiglieto reservoir. The 13th of August 1935 the flood spillways of the main dam - Bric Zerbino - were unable to discharge the flood and both dams were overtopped. The main dam was not damaged while secondary dam - Sella Zerbino - collapsed. This paper describes in detail the rainfall event that caused the dam break and critically compares the historical peak discharge to the design discharges of the existing dams located in Northern Apennine region