Hampstead Heath’s bathing ponds are used more than twice as much as they were a decade ago, according to stats released by the City of London Corporation (CoLC).
The CoLC, which manages the Heath, also revealed that £747,000 was spent on operating the three ponds in 2019, and the ponds only brought in £67,000 in ticket sales and donations.
Heath bosses have published these figures while consulting with stakeholder groups over a "review" of swimming arrangements after it received advice from the Health and Safety Executive saying it should consider hiring more lifeguards in order to cope with record numbers of visitors.
The CoLC thinks just 3.7 per cent of pond swimmers pay the unenforced charges which currently exist - and were introduced in 2005.
Following discussions, proposals will be developed and considered at the Heath's Consultative Committee, before a decision is made by the Hampstead Heath Management Committee in March 2020.
Karina Dostalova, who chairs the CoLC's Hampstead Heath Management Committee, said: "The Heath's swimming facilities are becoming more popular every year. They are a prime space for Londoners to get outside and take time out from their busy lives.
"To be able to keep it this way, we want to make sure that we have the right resources in place for visitors to safely enjoy all the Heath has to offer."
A decision as to how to proceed, which may or may not - CoLC say - involve introducing compulsory charges.
The Hampstead Heath Swimmers' Forum is expected to discuss the issue and possible proposals later this evening (Tuesday).
Swimming groups and stakeholders - such as the United Swimmers' Association's Robert Sutherland Smith - are concerned by the speed of discussion, and worry compulsory charging will be "pushed through".
But other swimmers have welcomed discussion of how to better manage the ever-busier Men's, Ladies' and Mixed Ponds.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here