Outlook on Games’ opening ceremony in Seine remains murky. GETTY IMAGES

The Paris 2024 plans for a grandiose inauguration on its famed inner-city river have yet to receive the official green light, as town hall officials deemed its water "too dirty" to compete in and postponed an Olympic rehearsal on Monday due to strong flow.

The latest test results from 16 June revealed that the triathlon and open-water swimming events are not compatible with the quality of water, officials said. "Samples from the Seine do not meet the standards we will have this summer," Paris region prefect Marc Guillaume admitted on Friday after online public analysis showed concentrations of E. Coli significantly higher than the recommended limit in four locations of the river from 10 June to 16 June.

The expected symbol of the 2024 Games is once again under threat of being reconsidered, this time due to concerns within. Along with a recent warning for expected heatwave in August, the incessant rain is currently the biggest weather-related concern for organisers, as regular downpours in May and June have led to these unusually strong currents and subsequent poor water quality.

The weekly report from the Paris region claimed that unseasonably rainy weather was the main reason for the high levels of two types of faecal bacteria, including E. Coli. "Water quality remains poor due to... rain, high flows, little sunshine (and) temperatures below the norm," it said. The Seine is currently registering a level five times stronger than its normal summer reading, meaning it would be impossible to "draw the most relevant lessons" from a rehearsal, city authorities and Olympics organisers explained.

A rehearsal for the inauguration that was scheduled for Monday was also postponed because of the rising flow, according to officials, and weather forecasts from the public agency Météo France for the next two weeks aren’t looking great either, with rainy weather expected until 5 July.

Paris mayor Anne Hidalgo already had to partially walk back her promise that she would take a Sunday 23 June dip in the river, which has been cleaned up in preparation for the Games and announced a new approximate date for her swim: the week of 15 July, after elections are held in France.

New infrastructure to absorb heavy rainfall, including the 50,000m3 Austerlitz reservoir, was expected to help reduce undesirable levels of bacteria that can cause serious health problems for competitors and the general public. However, this is so far proving to not be enough, despite an estimated investment of €1.4 billion, funded by the national government and the capital's authorities.

Paris mayor Anne Hidalgo posponed her swim in the Seine. GETTY IMAGES
Paris mayor Anne Hidalgo posponed her swim in the Seine. GETTY IMAGES

A cleaned-up Seine, available for swimming, was expected to be one of Paris 2024’s lasting legacies but —like other Olympics have proven before— it’s way easier to talk the hopeful, would-be talk than walk the sanitised, non-polluted walk.

"If the flow is too high, it will be a serious problem for the ceremony," hydrologist Jean-Marie Mouchel told AFP. While the Organising Committee of the Olympic Games (OCOG) insisted it was not worried, city officials said the water level made it impossible to "draw the most relevant lessons" from the now postponed rehearsal, which was to involve some 90 barges to transport teams to the opening parade.

In August last year, the swimming marathon test events were cancelled because the water was too dirty, as were the swimming legs on two of the four days of triathlon and para-triathlon tests.

The plan for Paris 2024 was to stand out as the first Games in history to celebrate their opening ceremony outside the Olympic stadium. So far, it’s standing out for additional headaches for the organising team, despite huge efforts to make the dream come to fruition.