There is no doubt that the famous River Seine, which runs through the centre of the French capital, will play a leading role in Paris 2024, but it will be that of a blessing or a curse.

Much will depend, as in so many aspects of life, on the results achieved. At the moment, these are hard to come by, although the organisers are confident that they will be turned around for the Games, as part of a process that will culminate in the grand celebrations on the Seine, the swimming events and the mayor's dip in its waters.

Like the works of the French Impressionist master Claude Monet, which captured a variety of perspectives, the Seine offers a variety of views.

Throughout history, it has seen it all, from the Vikings to D-Day, from revolutions to the first celebrations of freedom after the Covid-19 pandemic. Singers such as Marianne Faithfull, Hollywood stars such as Doris Day and even Queen Elizabeth II herself were treated to a cruise on the Seine during her first state visit to France after her accession to the throne.

So much has happened there that it has been neglected for decades. From being a fashionable place to swim naked in the 17th century to being banned for health reasons in the last 100 years.

These Paris Games brought a new challenge, not only to show France's greatness in trying to be environmentally sustainable, but to reclaim France's most famous river!

The European Union's second-largest economy has spent €1.4 billion to clean up the Seine, eliminating the faecal and other pollution that plagues the river with five projects to store and purify water. All will be operational in the coming weeks, giving organisers peace of mind.

The open-water swimming and triathlon events are scheduled to take place at the Pont Alexandre III, a marvel of 19th-century engineering at the foot of the Champs-Élysées, with the iconic Eiffel Tower looming in the background.

I deliberately used the word "planned" to emphasise that they are currently scheduled to take place there, but they may not if the water studies do not yield positive results. In other words, if they continue to show results that endanger people who come into contact with the water, including athletes.

Last August, just one year before the thirty-third Olympic Games of the modern era, the marathon swimming trials were cancelled because the water was too dirty, as were the swimming legs on two of the four days of the triathlon and paratriathlon trials.

The course for the men's and women's 10-kilometre events will start from the iconic Pont Alexandre III bridge and, with the Paralympics in the background, the Eiffel Tower, and will continue one kilometre downstream past other famous landmarks, including the Musée d'Orsay and the Grand Palais.

Perhaps fittingly, it passes the recently renovated Paris Sewerage Museum before looping back. The triathlon swims are shorter and return earlier. These routes have been chosen to showcase the beauty of Paris.

Cleaning up the river is also political, as swimming has been banned since 1923, despite promises by successive Paris mayors to open it up. In 1990, when he was mayor before becoming French president, Jacques Chirac promised that the river would soon be "clean enough to swim in" and that he would celebrate by taking a dip. He never did.

The current mayor, Anne Hidalgo, a strong proponent of green initiatives, made the same promise, as did President Emmanuel Macron some time ago. City officials argue that water quality has improved, but none of the samples taken between June and September 2023 met European standards for minimum water quality for swimming.

In early April, the Surfrider Foundation claimed to have analysed laboratory tests and concluded that the water of the Seine, which stretches almost 800 kilometres across France, remains contaminated and potentially dangerous in the Paris area, where the Olympic swimming events will be held.

The big problem is faecal matter. Bacteria in the water spike when heavy rains wash rubbish and untreated sewage from the banks and overflowing drains and sewers into the river.

The city tests the water at 14 points. In 2022, the water quality was considered "sufficient" at three of them, but it had deteriorated last summer. Last August's open-water swimming was cancelled after heavy rains - the worst in nearly six decades, according to officials - raised E. coli levels to six times the target set by the International Swimming Federation.

While some blamed the unpredictable weather for the Paris Games, others admitted that the failed tests for the team triathlon and, two weeks later, the para-triathlon swimming were due not to rain but to a "faulty valve" in the Paris sewer system. Something that could have been foreseen or at least taken into account to prevent it from happening in 2024.

The weather remains the "main risk", officials admit, and the main fear is "exceptional rainfall". But if the new water treatment and storage projects had been completed, "we wouldn't have had any problems during the test events last August," insisted the city's deputy mayor, Pierre Rabadan.

The only contingency plan for the swimming events is to postpone them for a few days. "There is no option to move the event, the triathlon and open water swimming will take place in the Seine next year," said Tony Estanguet, head of the Paris 2024 organising committee, after the cancellations last August.

It was also said, but in relation to the Opening Ceremony, that there was no Plan B and that it would go ahead exactly as the original plan, with the procession on barges along the Seine in front of a crowd that had to be reduced by half.

A few weeks ago, President Macron himself admitted that there was not only a Plan B, but even a Plan C for the party that will inaugurate the third Olympic Games to be held in France.

Opinions are divided as to whether or not it is appropriate to go ahead with the test despite the pollution of the Seine. "Even if the water is dirty, I would rather swim in an electric atmosphere in the centre of Paris than in an anonymous stretch of water," Italian double world champion Gregorio Paltrinieri told the Italian media last January.

After winning the silver medal at the World Championships in Qatar in February, France's Marc-Antoine Olivier said: "People may be afraid of what's in the water, but swimming in a historic place is going to be incredible."

"Of course a lot of people will try to make a fuss about the conditions, but if we can swim, there's no problem. They won't run the risk of us swimming and someone catching something," added Olivier. However, if the worst comes to the worst, triathlons could become "duathlons" by removing the swim leg, as happened at some of the test events in Paris in 2023.

"It would be a shame, but we are adapting to a duathlon," said Britain's Beth Potter, who won the individual test event. In conclusion, with just 90 days to go until the Paris 2024 Games, it is not known how Mother Nature will behave, whether it will rain or not, and how much it will rain before the Games to complicate the situation or not. Nor is it certain that the clean-up work, which has cost the public purse so much, has been resolved.

The only thing that is known is that the Paris organisation will try to play its best card until the last moment: its spectacular Seine as host. It will be up to them to be an angel or a demon in this novel.