(Paris) Anxious countdown for organizers: the Seine carried too much water and bacteria one month before the opening of the Paris Olympic Games (July 26–August 11), reinforcing doubts about the good performance of the events in open water and the opening ceremony.
In Île-de-France, the gloomy spring gave way to an early summer worthy of the name, dry and sunny. But the precipitation of recent weeks still has serious hydrological consequences.
The river quality analysis reports published Friday by the town hall and the regional prefecture, covering the week of June 17 to 23, showed concentrations of fecal bacteria sharply increasing compared to the previous two weeks.
The content of Escherichia coli and enterococci must not exceed 1000 and 400 colony forming units (CFU)/100 ml respectively for the tests to be authorized.
While E. coli concentrations were generally between 1000 and 5000 CFU/100 ml in the first half of June, they fluctuated between 2000 and 10,000 – with a peak at 13,000 – at the start of the third week, between 2000 and 6000 at the end of the week.
As for enterococci, with values generally between 100 and 500 CFU/100 ml in the first half of June, they rose above the 1000 or even 2000 mark for several days.
“Water quality remains degraded due to an unfavorable hydrological context: rain, high flow, little sunshine, temperatures below seasonal standards and pollution from upstream,” summarize the town hall and the prefecture.
“We expect things to improve this week given the weather,” commented the regional prefecture to AFP.
On Wednesday, prefect Marc Guillaume warned that the river would not be swimmable at the beginning of July.
The moment of truth is approaching for the organizers: after the opening ceremony, the Seine must host the triathlon events (July 30 and 31, August 5), swimming-marathon (August 8 and 9) and paratriathlon (1 and 2 september).
In the event of intense precipitation, untreated water –– a mixture of rain and wastewater – can be released into the river, a phenomenon that retention structures inaugurated before the Games are intended to prevent.
Town hall and prefecture also emphasize that the rains of June 17 and 18 allowed the Austerlitz basin, inaugurated at the beginning of May, to operate for the first time.
If these works prove insufficient in the event of heavy rain, plan B consists of postponing the tests for a few days, but not changing the location.
But attention is now focused more on the flow of the Seine, “six times higher” than usual during the week observed: it was 666 cubic meters/second on Sunday, while it is normally 100 to 150 cubic meters in this period.
The rehearsal of the opening ceremony scheduled for Monday was postponed because of the excessive flow.
Although it has since fallen again, it has stagnated since Thursday at a plateau of around 430 m3/s.
Not only does a high flow threaten the safety of swimmers, it is also problematic for the nautical parade of the opening ceremony, because it increases the speed of the boats, and therefore disrupts the passage times of a carefully timed show.
After the return of rain expected in the first week of July, Météo France indicates that “no scenario” emerges for the last three weeks until the Olympics.
The president of the Olympic organizing committee, Tony Estanguet, estimated Wednesday on France Inter that we “will see more clearly in mid-July”.
“We are still confident about the progress of the competitions in the Seine and the opening ceremony,” he assured the day before.
Paris Mayor Anne Hidalgo, who postponed her historic plunge into the Seine due to bad weather and early legislative elections, now plans to take a dip the week of July 15.
