What everyone is talking about this week: Would you swim in the River Thames?

Well, would you? Probably not in its present, deleterious state, but what if it were safe? Now, perhaps?

For a month, the people of Paris, France, have been enjoying something akin to Highgate Ponds with a view of the Eiffel Tower, an experience made possible by a €1.4 billion clean-up initiated for last year’s Olympics. Although it may be tempting to picture rat-infested waters in the city that gave us Ratatouille, the project has not been half-hearted. Parisians are ecstatic. Londoners — and Britons — are jealous.

Demand for Thames swimming in urban areas is high. Freshwater bathing in the UK has exploded in popularity post-pandemic, despite the deterioration of our rivers through sewage spills and poor maintenance. Copenhagen in Denmark and Vienna in Austria, which regularly top the Economist Intelligence Unit’s index of the world’s most liveable cities, offer in the Harbour and the Danube waterways that are popular with citizens in search of a healthy, refreshing pastime.

People over here want the same. Last year, London Mayor Sadiq Khan pledged to ‘clean up our waterways too and build a plan to make rivers swimmable again within 10 years’. Yet the Port of London Authority insists that the tidal Thames, which flows from Teddington Lock out to the North Sea, will never be safe to swim in. Some have thrown caution to the wind (so-called ‘guerilla swimmers’ regularly team up for laps between Kew and Hammersmith Bridges), but goodwill alone won’t cut it. A clean-up is needed and will come at a heavy cost. The Thames is grislier than the Seine, which is quainter, narrower and easier to tame

The tidal Thames has welcomed lidos before: from 1875–85, people could take a dip in an indoor pool along Victoria Embankment. A 2021 study by architectural practice Studio Octopi showed how a Thames Baths pipedream could become reality, with modular pools opposite Old City Hall that could rise and fall with the tide and use reedbeds to filter out junk. Progress has been hampered by chronic under-investment and massive debt (Thames Water owes a staggering £19 billion). Many will write off the situation as Kafkaesque, but some in politics believe there’s a clear solution: bringing water companies back into public ownership. With such demand for swimming in the Thames, this is a landmark proposition.