For the first time since weekly testing began, the River Seine was suitable for swimming for several consecutive days in late June, according to bacterial analyses released on Thursday, just four weeks prior to the Olympic events planned in the river.
The positive results were achieved despite the river’s flow being “four to six times” higher than the “usual summer rate,” Paris City Hall and the regional prefecture note in their weekly report. This improvement is largely due to sunny weather in the early days of summer.
The Paris Olympics' organisers are not deterred by the Seine’s unusually high flow. According to Thierry Reboul, Director of Ceremonies in the organising committee, the opening ceremony can be adapted to accommodate up to 500 cubic metres per second (m3/sec).
Due to persistent heavy rainfall in the Spring and from the start of June, the Seine’s flow sat above 300 m3/sec for most of the month. This is roughly two to three times the typical summer rate, which is usually between 100 and 150 m3/sec. At times, the flow even exceeded 600 m3/sec.
However, Reboul explained that the flow could cause issues with the speed and manoeuvrability of the boats during the opening ceremony.
He stressed it was vital to avoid flow rates over 500 m3/sec because the boats would not just move at 9 km/hr, but at 12 km/hr. Since the artistic showcase will primarily take place on the quays, bridges, and roofs and is synchronised with the river parade, any changes in flow rate would “disrupt the entire timing.”
