Millions of individual houses built on clay soils have been affected by the drought. Insurers are doing their accounts: the total balance this year should exceed two billion euros in compensation. And they warn: the risk will triple by 2050.
2022 is indeed an exceptional meteorological year. The first evaluation of the drought that continues to affect the territory yields an amount of compensation for damage due to “shrinkage-swelling of clays” (RGA) that is in a range of 1,600 to 2,400 million euros according to , the organization that federates the insurance industry. We will know in the coming months if the previous record of 2003 -2,118 million euros of compensation- will be broken. France is thus experiencing a major drought for the sixth time in ten years. While 2003 still temporarily holds the record, 2018 ranks third in RGA’s annual compensation rankings, ahead of 2020 and 2017, with 2019 and 2016 ranking eighth and ninth respectively. This recurrence increases the number of disasters, gradually yielding the most resistant land to AGR due to this prolonged absence of water. In addition, these periods are getting longer. More than half of the droughts occur outside the summer period: 22.7% between April and June and 20.6% in October-November, compared to 45.2% between July and September and 11.4% between January and March.
The 2022 drought is both spring and summer. © Meteorology France
RGA, what is it? When it is very dry, the clay loses its water and shrinks. This phenomenon is attributed to its own structure: a stack of phyllosilicate particles less than two microns organized in sheets that have weak bonds. It is in these interstices that water molecules slide. When it is dry, the water disappears and the structure retracts, causing landslides that destroy the foundations of the houses and crack the walls.
More than half of French individual houses affected
The particularity of the RGA is its discretion. Hundreds of thousands of homes are affected without major incidence beyond the perimeter of the affected municipalities.[…]