Paris 2024 plans to hold swimming events, as well as the Opening Ceremony, on the Seine could be impacted by delays over vital sewage pipe repairs ©Paris 2024

France’s €1.4 billion (£1.2 billion/$1.5 billion) plan to make the River Seine clean enough to host swimming events at the Paris 2024 Olympics could encounter problems over access to vital sewage pipe renewal.

One of the key elements of the Paris 2024 hosting is ridding the rivers that run through the capital of pollution that currently means swimming in them is banned.

Paris 2024 organisers also plan to use the Seine to stage an innovative Olympic Opening Ceremony on July 26 next year.

"Make the Seine and the Marne swimmable," tweeted the French President Emmanuel Macron.

"This is our objective for 2024. 1.4 billion euros invested, half of which by the State.

"At [500 days out], we are on track to achieve what will be one of the greatest legacies of the Paris 2024 Olympic and Paralympic Games."

However, one of the leaders of the project to clean the rivers and make them suitable to host competition, Claire Costel, has acknowledged that there may be difficulties in doing all the required work in time on outdated sewage pipes, many of them from houses and offices on the river banks, that overflow during heavy rain, as reported by the New York Times.

City authorities have set up huge infrastructure projects to create a more robust sewage and runoff system.

Plans to make the River Seine clean enough to swim in are part of an overall legacy target of the Paris Mayor Anne Hidalgo ©Getty Images
Plans to make the River Seine clean enough to swim in are part of an overall legacy target of the Paris Mayor Anne Hidalgo ©Getty Images

But that involves going door-to-door and convincing thousands of owners to let crews overhaul their sewage pipes.

Although the Government is offering to subsidise such work, Costel admits: "It’s delicate.

"We can’t force them to open their doors."

Even if officials manage to get pollution down to acceptable levels there are fears that heavy rain during the Games could undermine their efforts.

Paris 2024 officials regard the cleansing of the rivers as an important investment to transform the city well beyond the Olympic Games.

Anne Hidalgo, the Mayor of Paris, has also included reducing cars in the city centre and improving air quality as key parts of her agenda, and she is hoping that the Seine will eventually be open for public swimming in 2025.

According to reports, the city and region of Paris want to build 23 sites along the Seine, including five in the city and 18 in suburban zones, which would provide protected swimming areas.

If officials succeed in their cleansing efforts it would re-establish a tradition of swimming in the Seine that was ended by a formal ban in 1923.