The organizers of the Paris Olympic Games are crossing their fingers more than ever. “The Seine will not be swimmable in a few days,” said the prefect of Ile-de-France Marc Guillaume this Wednesday on France Info. Less than a month before the start of the Games (July 26 – August 11) and the events planned for them, this is inevitably bad news. The senior official highlighted “the flow of the Seine that we have, again this morning, at more than 480 m3/second”.
This high flow, caused by precipitation at the end of a rainy spring, led to the postponement of a rehearsal of the opening ceremony, which was scheduled for Monday. It then rose to 650 m3/second.
A high flow rate “mathematically increases the speed of the boats” which would currently take “fifteen minutes less” on the route, the regional prefecture explained on Friday. The usual flow rate in summer is around 100 m3/second.
“We have not had weather conditions, for six months, which are very classic,” recalled Marc Guillaume, emphasizing that the swimming plan carried out for almost a decade by the State and the Ile-de-France communities, with 1.4 billion euros of investment to make the Seine and the Marne suitable for swimming, “is not enough if the weather is autumn or winter”.
The prefect and the mayor want to go swimming
The regional prefect intends to swim in the Seine, to set an example, “the day we can”. The mayor of Paris Anne Hidalgo, who postponed her historic dive into the Seine due to bad weather and early legislative elections, planned to swim the week of July 15 “or the week after”, that of the ceremony opening.
In an interview at West France On Wednesday, she said she was “very confident” that favorable weather would arrive in time for the Olympics.
Suspense remains over the holding of the Olympic events since the “test events” of August 2023 which had to be largely canceled due to insufficient water quality.
A plan B that isn’t really one
In the event of intense precipitation, untreated water – a mixture of rain and wastewater – can be released into the river, a phenomenon that retention works inaugurated just before the Games are intended to prevent.
Plan B consists of postponing the tests for a few days, but not changing location.