A few things to reply to from the comments: - Re water quality: the PLA (despite having the powers to do so) have never once prosecuted a water company for illegal sewage discharge. Indeed, they make money from such discharges by charging for the right to discharge water into the Thames. Their harbour master has stated publicly that they PLA don’t accept they have any duty to stop rowers getting sick as a result of contact with sewage. - Re currents & the strength of the river. Different activities could happen on different parts of the river. No one is proposing a paddling pool next to the London Gateway Port! However, swimming in the river is eminently possible on the upper tidal reaches (say around Richmond). There was also a proposal for a magnificent floating lido in central London, which would have been an amazing addition to the city, but which was sadly vetoed by the PLA. - Cost: the PLA extracts money from the Thames, which could fund a swimmable Thames, but currently spends it on inflated salaries & pensions for its completely unaccountable quango-crat managers. I believe that Londoners should have some say on where they money generated from our river is spent, but there is currently absolutely no such accountability for the PLA.

A reminder that we cannot have this in London, not only because the Thames is too polluted, but also because we have left the tidal Thames in the sole hands of an unaccountable legacy organisation founded in 1908 called the Port of London Authority (@LondonPortAuth) which basically exists to pay its own inflated salaries whilst pretending that London is still the greatest port of the Empire. This organisation is generally useless, but quite effective at blocking both nature restoration on the Thames & the river actually being used by the people of London.