Gleno's Dam Collapse

On December the 1st, 1923, the Gleno dam, located in the Scalve valley (Lombardy), collapsed.

The dam, a multiple arches structure, was partially sudden breached and the consequent flood caused more then 400 casualties. Such event emphasized the need of a 'structural safety' for Italian dams, but, it should be noted that the design of the Gleno dam was approved by the Ministry of Public Works only five days before the publication of the first comprehensive dam regulation in Italy.

Durability is of the utmost importance because dams are one of the few structures built to last almost indefinitely. In Italy the Gleno Dam, a multiple arch dam 43 m high, suddenly failed on 1 December 1923 when one of the buttresses cracked and burst in a matter of a few minutes. The cause was attributed to poor quality workmanship: the concrete in the arches was poor and inadequately reinforced with scrap netting used as hand grenade protection in the war and there was evidence of lack of bond with the foundations.

On December 1 st 1923, at 7.15 a .m., some hundreds kilometres north-east far from Ortiglieto: the Scalve Valley (Alta Bresciana - Orobiche Alps) was hurt by a terrible accident. Owing to a rainstorm, the Gleno dam, on the homonymous river, almost completed, collapsed letting flow into the narrow Alpine creeks more than 6 million water and detritus. The flood swept everything away, till the Iseo Lake and 400 persons about died. The following inquiries of the competent Authorities will ascertain numerous defects both in designing and in constructing.