FloodsDifferent lessons from past floods

More and more frequent extreme weather events lead to new projects on risk management and spatial planning. Past experiences represent an added value and suggest the importance of greater involvement of local communities.

Luckily, past mistakes can sometimes be useful for present or especially future decisions. This can apply to spatial planning and management in response to natural disasters and extreme weather events.

In this field the role of people living in a given territory and their participation in decision making processes could be crucial in reducing and better managing the major negative effects of natural catastrophes. Simone Frigerio, researcher at the Research Institute for Geo-Hydrological Protection, Italian National Research Council, explains: “Local population-based crowdsourcing is becoming more and more a key strategic action for gathering real-time information.” Italy is a country with a high landslide risk: 82 percent of the municipalities are at a high hydrogeological risk. In this context, two historical tragic events, due to natural disasters, have shown that the role played by the local communities did make a difference in saving lives.

9 October 1963: the Vajont artificial lake, Friuli Venezia Giulia and Veneto Regions, Northern Italy
A piece of mount Toc collapses into the Vajont dam causing more than 2,000 victims and washing away villages and communities. It has been defined by the United Nations as “the most severe natural disaster in the world caused by human error.” The ‘Great Vajont’ hydro­electric project aimed to transform the valley of the Piave river into a giant source of hydropower for Italy, disregarding the historically known instability of the mount, on which the dam was built. “Toc,” in fact, in the dialects spoken in the valley, means both “piece” and “rotten.”

‘The Vajont case represents the failure of a state-centered approach and a very bad example of public-private collusion, ignoring experience and traditional knowledge, and not including local development criteria for decision making. This is why it’s an important example to be taken into account for future developments of territorial management,” comments Giovanni De Lorenzi, director of the Vajont Foundation.

CORDIS reports that since the 1950s, the local communities, had never been involved in any territorial spatial management decisions. Their protests were largely disregarded because all that was traditional, unscientific and they were therefore ignored and branded as old fashioned instead of as “development.” The dominant communication model between science and lay people at that time assumed that scientists and experts were sources of absolute authority, whilst the local inhabitants had no relevant knowledge and needed to be educated.

“Vajont was a lesson, not only for field experts or engineers. It was the mirror of a society in which the population is a victim with no role, and completely excluded from binding technical decisions. Local inhabitants are the most expert witnesses; elderly generations provide the informal but real database on the evolution of the environment at local scale. Vajont was the most impressive example of this. Entire villages wiped out, people robbed of their past and victims of the system,” concludes Simone Frigerio.

29 August 2003, Malborghetto-Valbruna, Friuli Venezia Giulia Region, North Eastern Italy
Cucco post-event 01A severe flash flood throughout the Fella river basin hits the village as a result of two extreme events: a storm (355 mm of rainfall within 3 to 6 hours) and the condition of the soil, extremely dry after an anomalous drought. The water transported sediments, stones, shrubbery and trees into the village and within two hours 100 houses were buried. The flash flood claimed two lives and caused almost €1 billion worth of damage. Approximately 600 residents had to be evacuated.

— Read more in Italy, Vajont “tsunami” and Malborghetto-Valbruna floods: such different lessons from the past