Organisers of the Paris Olympics, who are praying for fine weather during this year’s Games, said on Wednesday they had delayed plans for a rehearsal of the opening ceremony on the Seine for the second time because of the river’s high water levels.

Following a stormy month of May that has seen regular downpours in the French capital, a rehearsal scheduled for May 27 has been cancelled – as was a previous one on April 8.

“It will take place when the weather conditions allow for it,” officials in the Olympics ministry and the local organising committee told AFP.

The Paris Games are set to open on July 26 with a boat parade on the Seine – the first time a Summer Olympics has begun outside the athletics stadium – under plans that are widely seen as high-risk.

The Seine is also set to host the open-water swimming and triathlon during the July 26-August 11 Games, providing that pollution can be reduced to safe levels by the time athletes arrive in just over 60 days.

Officials have consistently warned that heavy rainstorms before or during the Games could overwhelm the Paris sewerage system, leading to discharges of untreated fecal matter into the waterway.

The latest available data – as collected by water charity Surfrider in the middle of May – showed levels of the E.Coli bacteria more than four times the authorised level.

E.Coli is a key indicator of the presence of human waste.

Paris authorities and Olympic organisers insist that new infrastructure, including a wastewater treatment plant and a rainwater storage facility, will be in operation by the time the Olympics begin.

Cleaning up the river Seine is seen as one of the key legacy achievements of the Paris Games, with mayor Anne Hidalgo promising three public bathing spots for locals next year.

A new poll released on Tuesday delivered more worrying news for organisers, with the percentage of French people who say they plan to follow the Games falling significantly.

Only 51 percent of people surveyed told pollster Toluna Harris Interactive that they planned to follow the sport – down eight points since January and a far lower rate than in other parts of the world.

A total of 71 percent of respondents in Japan and South Korea said they would watch, while 68 percent of Americans and the same number of fellow Europeans intend to enjoy it.

Paris 2024 organisers insist that last-minute nerves and negative media coverage are typical in each Olympic host country before the Games.

They remain confident that the “iconic” locations being used for the sport around the French capital, as well as some domestic sporting success, will help generate enthusiasm and national pride once the event begins.