Olympic athletes in urban rivers: is it in-Seine?
With the eyes of the world on the French capital, we unpack the Olympic mission to make the Seine swimmable again.
05/08/24
Blog
As the Olympic Games approach their denouement, there has been no shortage of headlines so far. We have watched in shock, awe, and admiration as global superstar Simone Biles cements her legacy, swimmer Léon Marchand has become the most beloved man in France, and Sir Andy Murray ended his tennis career with a typically heroic fight to the end. We also cheered on particularly enthusiastically as our ambassador, rower Imogen Grant, stormed to gold in the women’s lightweight double sculls. But another of the big talking points since the soggy-or-spectacular opening ceremony has been the water quality in the River Seine.
The relentless wet weather on the opening weekend led to intense speculation over whether the triathlon event would go ahead as planned, so few were surprised at the announcement that the men’s race, originally set for Tuesday, was postponed. On Tuesday afternoon, we were told there was a 60% chance that the men’s and women’s races would happen on Wednesday – a tense wait for organisers and athletes alike.
Even as we woke up in the UK to the news that the triathlon was on, conditions remained precarious throughout the women’s event as the athletes had to negotiate the strong river current as well as a toe-curling number of crashes in the cycling segment. When they eventually got going, the men enjoyed easier conditions despite the rising temperature.
What brought us to this point?
In the UK, we hear a lot about the Victorian infrastructure that contributes to unacceptable levels of sewage pollution. The French equivalent is ‘Napoleonic’ infrastructure which, like ours, is a network built in the 19th Century that combines wastewater and stormwater. We know that when this system is overwhelmed, untreated sewage can be discharged directly into waterways to prevent it from backing up into homes or businesses.
More than €1.4bn has been spent to upgrade Paris’ sewage system and build new underground water storage facilities to achieve the dream of making the Seine safe to swim in. Those involved were no doubt inspired by the success story of what is largely acknowledged as the world’s leading water management city, Copenhagen, where locals have enjoyed city-centre swimming locations known as harbour baths since 2002.
Copenhagen’s cleanup effort amounted to a $440m investment to reroute wastewater, build overflow barriers and increase underground water storage. The city’s swimming sites are just one element of a wider national effort to prioritise water that started back in the 1970s. Now, drinking water is sourced solely from protected groundwater reserves where only aeration, pH balancing, and filtration treatment methods are required. The Danes are also known for their water efficiency, using far less water per person per day than most other European countries – the highest water rates in Europe help to incentivise this thrift.
Even then, there are rare occasions when rainfall is high and therefore water quality in Copenhagen is not up to standard and that’s where the other branch of Denmark’s water transformation comes in. Investment in technology has led to the development of a sophisticated alert system, run by a private company, which uses factors like the weather forecast, existing water levels, and tide tables to predict when the water will not be safe to bathe in and issue mobile phone alerts to locals.
France’s effort to achieve bathing water quality in the heart of its capital has different challenges to Denmark. For instance, Paris’ metropolitan area has a population roughly six times greater than Copenhagen’s, and has a far greater geographical span.
Why didn’t the cleanup effort work?
While the foremost risk factor for bacterial water pollution identified by World Triathlon is human and animal faecal matter, namely sewage, there are other contributors. Those include the presence of rodents or bird colonies, industrial features, or eutrophication, where the presence of blue-green algae is proliferated by the presence of nutritious matter which is often washed off agricultural land.
As the eyes of the world have been on Paris, this story demonstrates the scale and complexity of the challenge to make rivers fit to swim in. Rivers are among the most delicate ecosystems of all, and water quality standards for sports competitions are stringently policed by sports federations such as World Triathlon.
Despite water quality tests in the week before the Games started suggesting the river would be safe to swim in, the drenching of the city during the opening weekend led discussion about the viability of the triathlon event to build rapidly. However, all that rain only filled the new water storage tank beneath the streets of Paris up to 20% capacity[i], suggesting the high levels of bacteria detected ahead of the postponed men’s triathlon are not likely to have been caused by sewage spills in the city centre, but from pollution further upstream.
What have we learnt from the mission to make the Seine swimmable?
At The Rivers Trust we talk a lot about the need to take a catchment-based approach to water quality concerns; the situation in Paris illustrates exactly why we champion this approach. Although a lot of water quality monitoring and investment for designated bathing water sites is focussed on CSOs and sewage treatment immediately upstream of them, what happens on the land and further up a river and its tributaries is equally, if not more, important .
Events in Paris also serve as a reminder of the far-reaching impacts of extreme weather, which is an ever-more likely occurrence as a result of climate change. While heavy rain causes pollution one month, a period of hot, dry weather and increasing demand for abstraction can have equally devastating impacts as pollutants are at a higher concentration.
The Paris 2024 organisers have been resolutely ambitious in their plans to make Paris itself, and the river it was founded upon, the centrepiece of these Games. Once they have ended, plans to open up to 26 public pools along the river will contribute to the buzziest of Olympic buzzwords: legacy.
All of this might be well received in outdoor swimming circles but has been controversial locally. Some Parisiens even threatened to defecate directly into the river in protest at the cost of cleaning it up, which they see as being at the expense of remedying other social issues. Although the races finally went ahead and delivered a great spectacle, the jury is still out on whether the master plan was worth it. Was the event planned with athletes and spectators in mind, or Parisien officials? Was it a genuinely transformative plan to make Paris a more liveable, resilient city, or just political grandstanding?
Ultimately, no-one can offer objective, definitive answers to these questions – and certainly not now. Illness has been reported amongst the athletes who have swum in the river has not been widely reported, but did prevent the Belgian team from participating in the mixed triathlon relay. In the coming years, it will be interesting to see how many public pools do open along the banks of the Seine, and whether they do make Paris a more enjoyable place to live, in the face of increasing summer temperatures. But, as we strive to for wild, healthy, natural rivers, valued by all, we can certainly applaud the attempt.
