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The criticality of this section was known: when the great flood occurred, a leak in extremis was prevented at the same point
the case
Francesco Dondi
Daniele montanari
It was January 19, 2014 and the bank of the river Secchia, in San Matteo, gave way, flooding Bastiglia and Bomporto, lapping up the Bassa. But few know that in those dramatic hours another flood was avoided at the last minute and precisely in the area of via Tronco where the embankment was sold on Sunday. The reconstruction of this dramatic rescue is related in the “Technical-scientific report on the causes of the collapse of the banks of the Secchia River”, prepared by the scholars who investigated the natural disaster. And also in the Panaro embankment, the responsibility was attributed to the animals, oblivious to the disaster that led the Prosecutor’s Office – prosecutor Pasquale Mazzei- to request the closure of the investigation without sparing harsh criticism of the control system and the responsibilities of the chain. I send. For now, the investigations have not yet been opened, but the Modena Prosecutor’s Office awaits reports and complaints from the parties to initiate an investigation file: “culprit disaster”, suggested Forza Italia senator Enrico Aimi.
But to understand what happened in the afternoon of 2014 in Gaggio it is enough to reread the documents. This collapse was repaired thanks to the timely intervention of a group of technicians and volunteers who are part of the Municipal Civil Protection Group of the Municipality of Castelfranco Emilia led by the Mayor in Charge, some technicians from Aipo and the Cooperativa Modena Edilterrazzieri with mechanical means and men . Among them are Mr. Daniele Caretti, who is also Coadjutor of the Provincial Police – Wildlife Office – and Mr. Giovanni Molinari ».
Caretti, contacted yesterday morning, chose not to comment on the incident, but admitted the salvific intervention. And it is precisely the curate of Nonantola who is among the greatest experts in embankments, including that of via Tronco where numerous risks were identified due to the burrows dug by the animals.
“This stretch of the embankment – the report continues – was monitored with special attention for having been affected by dens of wild animals such as, in particular, the porcupine, which had been observed and closed in the past. The landslide produced a local descent of the summit of about 3 meters. The collapsed land would have been affected by seepage and erosion phenomena if it had not been quickly compacted with a bulldozer that intervened on the site.
Therefore, the Via Tronco embankment has been sensitive to the presence of wild animals for some time and, at least until 2014, burrows were identified and marked. But obviously something has changed if Aipo now says that he has not received any reports on that short stretch of the embankment.
“A recent or very recent problem must have arisen – underlines the engineer Luigi Mille, director of Aipo – something foreign to the knowledge possessed by the designers who drew up the plans for the works on the Panaro embankments which, having already reached an advanced stage It will be completed in 2021. Among the areas to intervene, it is not considered because there was no criticality. There were no problems reported even by volunteers (always invaluable in their contribution) monitoring foster animals such as otters, foxes, porcupines, and badgers. In recent days the presence of animals has been reported in other sections, but not in that one. It must also be said that its detection is not easy even with the latest equipment.
Aipo has recently acquired 18 drones equipped with infrared detectors capable of recognizing heat sources even at night. “We take them first to detect discharges in rivers, thinking in particular of the situation of the Seveso in Milan – he explains – but they can also be useful to identify the presence of animals. In the case of fossils, however, the action is conditioned by the fact that, as foxes show, they are usually outside the burrow. Then it can happen that the drone passes over an embankment with holes in a burrow but does not detect them because the animal is not present at that time.
Underlining full harmony with the analysis of the situation so far carried out by the regional councilor Irene Priolo, Mille points out the “height” of the embankment: “The” hydraulic free “, which is the difference between the water level and the one after which Leakage occurs – he explains – it remained a meter and a half even at the breaking point: there was no overflow, in fact there was still a margin of rise much higher than one meter. There something happened that we have not yet explained. ”
In cases like this, one sometimes wonders if a river dredging, that is, a digging operation at the bottom of the river to remove sand, gravel and debris would not have been useful. But the director is peremptory: «Dredging should only be done in areas where over-accumulation is created, identified in consultation with the Basin Authority, and this was not indicated. The utmost care should be taken when performing these operations: careless dredging does not solve problems, but creates them because increasing water velocity can increase erosion action. The cause of what happened is certainly not the lack of dredging. –
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