A hundred years after the tragic disaster that in 1923 led to the collapse of the Gleno Dam and the death of hundreds of people, today what remains of that great engineering work constitutes an open-air museum. The history can still be observed with vibrant energy in a place where nature is, inch by inch, reclaiming its space.
Whether it is to commemorate the event or simply admire the natural spectacle of the valley, the Gleno Dam today constitutes a destination of sure interest, away from the crowds of tourists, but still rich in surprises.
What is the Gleno Dam and where is it located?
The Gleno Dam was a multiple arch buttress dam built on the Gleno Creek in the Valle di Scalve, a valley in the northern province of Bergamo, in Lombardy. The dam was constructed between 1916 and 1923 with the purpose of producing hydroelectric power for the nearby industries and towns. The dam was 43 meters high and 260 meters long, and could contain up to 6 million cubic meters of water in a reservoir that covered an area of 400,000 square meters. The dam’s power plant had an installed capacity of 3,728 kW.
The dam was located at an altitude of 1,535 meters, surrounded by the majestic peaks of the Eastern Alps, such as Mount Gleno (2,882 meters), Mount Redorta (3,038 meters) and Mount Presolana (2,521 meters). The area is part of the Orobie Bergamasche Regional Park, a natural reserve that protects the biodiversity and the cultural heritage of this alpine region.
What happened on December 1st, 1923?
On December 1st, 1923, at 6:30 am, a crack appeared on one of the buttresses of the dam. Within minutes, the central section of the dam collapsed, releasing a massive wave of water that swept away everything in its path. The water reached a speed of over 100 km/h and a height of over 40 meters as it descended along the valley.
The villages of Bueggio and Azzone were completely submerged, while Dezzo, Colere and Corna di Darfo were partially flooded. The water continued its destructive course until it reached Lake Iseo, about 60 km away from the dam.
The disaster claimed at least 356 lives, although some sources estimate a higher number of victims. Many bodies were never recovered or identified. The material damage was also enormous: houses, bridges, roads, factories and farms were destroyed or severely damaged. The economic and social impact of the catastrophe was devastating for the local communities, which had already suffered from the consequences of World War I.
What caused the failure of the dam?
The failure of the dam was attributed to several factors related to its design, construction and maintenance.
The dam was originally planned as a gravity dam with a slight curvature, but was changed to a multiple arch dam by the client to save money. The permit for this modification was not revised until after the dam was completed. The construction quality was poor: the concrete used for the arches was defective and reinforced with scrap netting that had been used during World War I. The connection between the dam and its foundation was also weak. Moreover, the dam was not properly inspected or monitored by the authorities or by the company responsible for its operation.
How is the Gleno Dam today?
Today, the remains of the Gleno Dam are still visible and accessible to visitors who want to admire this impressive monument of engineering and human folly. The collapsed section of the dam lies on the valley floor, while the intact parts stand on both sides of the creek. Behind them, a small lake has formed where some fish species have colonized. Above them, Mount Gleno dominates with its snowy summit.
The site has been declared a national monument in 2002 and has been equipped with information panels that explain its history and significance. The site is also part of an open-air museum that includes other historical structures related to hydroelectric production in the area, such as power plants, tunnels and pipelines.
How can you visit the Gleno Dam?
The Gleno Dam can be reached by following two easy trekking routes that start from Nona or Pianezza, both hamlets of Vilminore di Scalve.
The route from Nona follows a moderate path that crosses woods and pastures, while the route from Pianezza, which follows the trail n. 411, is steeper but more scenic, as it runs along the old road carved into the rock cliff. Both routes take about an hour and a half to reach the dam and offer stunning views of the valley and the mountains.
The best season to visit the Gleno Dam is from spring to autumn, when the weather is mild and the vegetation is lush. In winter, the access road to Pianezza is closed to traffic and a paid shuttle service is available. Alternatively, you can walk or ski along the road, adding about 4 km to the itinerary. In any case, it is advisable to wear appropriate clothing and footwear, and to check the weather conditions before setting off.
The Gleno Dam is a unique and fascinating destination for travelers who want to discover a lesser-known aspect of Italy’s history and nature. It is a place that evokes both awe and sorrow, as it reminds us of the power and the fragility of human endeavors. It is also a place that invites us to reflect on the importance of respecting and protecting the environment, as well as the lives and the memories of those who inhabit it.