"La grande mulette" has just resumed service on the Charente.
This dredger is at the heart of a devastation site started in 2019 and completely unprecedented in France in terms of its scale.
By 2027, 12 km of the river will be cured on either side of the Saint-Savinien dam, a town north of Saintes.
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Objective: to reduce flooding between this sub-prefecture of Charente-Maritime and Rochefort and limit the effects of ten-year and one-year floods.
Usually, only ports and estuaries are dredged on a regular basis.
But the presence of a dam commissioned in 1968 led to the creation of a “mud plug”.
The operation, estimated at 7 million euros, thus consists of removing 600,000 m3 of silt.
“It is imperative to maintain the uses of the river.
The mud has even solidified, we will have to hit hard, ”summarizes Jean-Claude Godineau, the mayor of Saint-Savinien and departmental advisor in charge of this file.
Lower the floods by 10 to 15 cm
Equipped with a sort of "rotary cutter", the dredge is thus entering its third campaign after a first experiment and a second season slowed down by the floods.
“Last year, 50,000 m3 were exported,” explains Sarah Rouger-Ristord, project manager for aquatic environments with the Department.
The sludge is transported by pipelines to several settling basins specially built for the occasion.
Nearly 28 hectares have been bought or rented to build them.
After settling, the silt is then spread on agricultural land as part of a partnership with local farmers.
Tests have confirmed their good composition and usefulness for crops.
“More than 10,000 m3 were spread this summer,” says Sarah Rouger-Ristord.
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According to Jean-Claude Godineau, this operation will "lower the floods by 10 to 15 centimeters and protect 1,400 homes and 800 additional businesses".
Another challenge for the site: re-establishing ecological continuity and restoring the habitat of the large mussel, a freshwater mussel threatened with extinction.
This large mussel can measure up to twenty centimeters.