It is 2:20 p.m. on Monday afternoon when the bottle of champagne, thrown by the mayor of Paris, Anne Hidalgo (PS), smashes on the tungsten carbide teeth of the tunnel boring machine of the Austerlitz basin (XIIIe) .
Symbolically baptized with the name of Sequana, goddess of Gallic Celtic mythology representing the Seine, the micro-tunnelling machine, piloted remotely from a station on the surface, will be able to begin its work next week.
To know how to dig a tunnel 30 meters deep under the Seine connecting between them a well located on the right bank, next to the forensic institute (12th century), another well, on the left bank, near the Gare d'Austerlitz, and a storage basin which will be dug from September under the former Square Marie-Curie (13th century), still near the station.
Objective: swimming in the Seine in 2025
"This basin, a cylinder 50 meters in diameter and more than 30 meters deep, will store more than 50,000 m3 of water (the equivalent of twenty Olympic swimming pools) in order to avoid, as is the case today, the discharge of waste water into the Seine in the event of heavy rain.
Then, this excess water will flow quietly into the sewer network to be treated, ”explains Colombe Brossel (PS), assistant in charge of the cleanliness of the public space.
Objective of this project for which the City is the contracting authority and which is due to be completed in May 2024: to drastically reduce the discharge of polluted water into the Seine so that the athletes of the 2024 Olympic Games can swim there, before the opening of several public bathing sites in 2025.
In total, the construction of the tunnel, the storage basin and the two wells will cost 80 million euros, including 30 million financed by the State and 13 million by the Siaap (interdepartmental union for the sanitation of the Paris agglomeration) , the rest being paid for by the City.
To François-Marie Didier, president of Siaap, who recalled that “bathing in the Seine was a promise of Jacques Chirac”, Anne Hidalgo, seizing the ball, replied: “And me, I will have achieved it!
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