Activities - Large dams risk

Attività Rischio grandi dighe

The Directorate-General for Dams of the Ministry of infrastructure and transport (MIT) monitors the safety of dams, starting with the engineering, construction, testing, and commissioning phases of new facilities, and periodically performs tests to re-evaluate their stability from a hydrogeological-hydraulic and seismic perspective.

Non-structural prevention activities, such as warning and planning, support these structural activities.

To guarantee the safety of the dam and downstream territories, specific procedures are established that require the activation of the National Civil Protection Service. In particular, different alert phases are foreseen to signal increasing severity that may result in the flooding of downstream areas.

The most severe phase is the "collapse" phase, which is declared when there is evidence of structural damage to the dam, landslides resulting in uncontrolled water discharge, or other phenomena that can lead to a catastrophic event, with loss of life or significant damage.

The dam operator is in charge of promptly informing all authorities involved for the activation of the National Civil Protection Service. The Region coordinates what needs to be done, but the Civil Protection Department will intervene if the scenario is extraordinary. The mayors activate municipal plans, inform citizens about risk scenarios, and decide on the actions to protect the population.

The IT-alert public warning system is activated upon declaration of the "collapse" phase to warn the population of areas downstream of a dam that a flash flood may occur. IT-alert message is then sent to the mobile phones of the potentially affected population to inform them of the possible danger.

A Civil Protection Document and a Dam Emergency Plan must be drafted for each large dam.

The Civil Protection Document addresses the actions to be implemented by the operator to activate the civil protection system. It is prepared by the branch of DG Dams of the Ministry of infrastructures and transport, in cooperation with the competent hydraulic authority, the regional civil protection, and the operator, and is approved by the competent Prefecture.

The Dam Emergency Plan (DEP) is drafted and approved by the Region or Autonomous Province in cooperation with the Prefectures territorially concerned. The Plan outlines procedures for managing flooding caused by discharge operations and the eventual collapse of the dam.

Municipal Civil Protection Plans acknowledge the information in the Dam Emergency Plans and include the areas at risk of flooding.

Near the watercourses downstream of the dams, signs generally indicate the areas most affected by the danger of flooding, including flash floods, due to spillway operations. Each dam is also equipped with an acoustic siren activated during discharge operations to warn people who may be in the area of the approaching flood.