The Mayor of London, Sir Sadiq Khan, has been cautioned that his ambitious pledge to create “swimmable rivers” in the capital by 2034 must prioritise safety messaging to avoid encouraging swimming in hazardous parts of the Thames.
The warning comes from the Port of London Authority (PLA), which manages the tidal section of the river. Currently, swimming in the Thames east of Putney Bridge is strictly prohibited due to the dangers posed by strong tides and busy water traffic.
Speaking at a City Hall environment committee meeting on Thursday, Grace Rawnsley, the PLA’s director of sustainability, highlighted the risks associated with the tidal Thames. “Every year, people die by going into the water. In 2023, there were 31 deaths, and in 2022, 109 rescues took place,” she stated. Rawnsley emphasised the need for public awareness, adding, “Headlines like ‘swimmable Thames’ can give the impression it’s safe to swim anywhere, which isn’t the case.”
The challenges of the tidal thames
The Thames is tidal for most of its course through London, only becoming non-tidal at Teddington Lock. Between Teddington Lock and Putney Bridge, swimming is allowed but not actively encouraged. East of Putney Bridge, swimming is banned entirely due to several dangers:
- Strong Currents: Tides running at around five miles an hour can overpower even the strongest swimmers.
- Waterway Traffic: The Thames is the UK’s busiest inland waterway, with over 20,000 ship movements and 400 events annually.
- Pollution: While efforts are ongoing to improve water quality, certain stretches remain unsafe for human contact.
Safety and awareness
In response to the PLA’s concerns, a spokeswoman for Sir Sadiq said: “The Thames and its tributaries are the lifeblood of London, which the mayor is committed to cleaning up and protecting so that all Londoners can safely enjoy the benefits of nature – including swimming where safe to do so.
“The tidal part of the Thames will never be safe to swim in, but the Port of London Authority is responsible for ensuring this water is more generally safe and accessible to the public. The mayor was delighted that the Port of London Authority joined him in pledging to turn the tide on our neglected waterways.”
In September, City Hall released a map identifying safe locations for wild swimming, such as Hampstead Ponds, the Serpentine in Hyde Park, and the Royal Docks near City Hall. The map explicitly states that the tidal Thames is unsafe for swimming, with potential future swimmable locations, such as Teddington and Albany Reach near Hampton Court Palace, currently deemed too polluted and unsupervised.
Cleaning up London’s rivers
Central to Sir Sadiq’s plan is improving the ecological health of London’s rivers, enabling them to support more wildlife and eventually become safe for recreational use. His team outlined several strategies to achieve this:
- Addressing sewage spills: Continuing pressure on Thames Water to reduce damaging discharges into the river.
- Sustainable drainage systems (SuDS): Expanding these systems to reduce pollution from urban runoff.
- Fixing sewer misconnections: Tackling domestic and industrial waste improperly connected to stormwater drains.
- Reedbeds and natural filters: Funding projects to install vegetation that naturally cleanses water.
Balancing ambition with reality
Despite the mayor’s environmental goals, the PLA remains concerned about the implications of public messaging. Rawnsley stressed the importance of managing expectations: “We’ve worked hard to reduce fatalities in the Thames over the last 15 years. It’s critical that the messaging supports our ongoing efforts to ensure safety.”
A vision for the future
Sir Sadiq’s vision for swimmable rivers extends beyond recreation. By tackling pollution and promoting biodiversity, his administration hopes to reconnect Londoners with their waterways while setting an example for urban river restoration globally.
However, experts warn that achieving these goals will require a careful balance of ambition and caution. As City Hall pushes forward, it must ensure that Londoners understand where and how they can safely enjoy the rivers – without putting themselves at risk.
