Around 4 p.m., this Wednesday, December 29, the RD 524 between Gières and Uriage had to be cut, following a mudslide and ice jams, in this place which is also called the Combe de Gières.
Part of these jams – trees and shrubs – fell into the Sonner River, which crosses the town of Gières. These woods were transported to a deposit beach, which is located in a district of the town where about 150 people live.
The backup plan triggered
At around 7 p.m., this deposit range filled up to 50% of its capacity. The mayor, Pierre Verri, then decided to trigger the PCS, the municipal safeguard plan. “We informed the population who live below this reservoir that there could be a _risk of overflow at night_, if the rainy episode did not abate. So cellars and ground floors could have been flooded. We would then have been ready to welcome these people to shelter them in a communal room. “
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Surveillance in place all night
But the situation stabilized around 11 p.m. “_The tank for 20 hours is no longer filling_“ explains the mayor, Pierre Verri. “The water is draining towards the Isère, but surveillance will be maintained all night. Every half hour there are municipal staff on the ground to check the water level.“
Upcoming work
Such an episode had already occurred in the town three years ago. To limit the phenomenon in the future, dThe work will be undertaken in 2022 upstream from the entrance to Gières, with the help of Grenoble Alpes Métropole.