Wild swimming children under 8 London

[Londonbabyland]

Looking for pointers to wild swimming locations for primary schoolers (under 8) in London (within 1 hr cycling from Central London). Has to be safe (probably only non tidal in Thames unless designated?) but not too shallow (1m or so depth). Lots online about adult wild swimming but little on kids. Royal Docks was a carnage in a designated kids section and so far only Hyde Park Lido came up in search.

Would appreciate recommendations!

Stoke Newington reservoir maybe?

Lee Valley has ‘open water swimming’ - not sure if that’s quite what you’re looking for. https://www.better.org.uk/leisure-centre/lee-valley/white-water-centre/activities

Under 8? Once 8, the Hampstead ponds. Parliament hill lido is lovely but not wild. Beckenham Place park?

The Serpentine in Hyde Park. Just checked. Kids from age 3.

Not checked whether they allow kids, but the Hampstead ponds?

Thank you for your replies!

Stoke Newington is from 14, Hampstead from 8.

Hyde Park is on the list, it's pretty adventurous though with all the duck muck.

Parliament Hill also on the list, although queues there usually stretch for miles (for timed sessions!)

Beckenham looks great, though it's 8 years min too except for school groups (6+).

Lee Valley looks good too,though from 14...

Water quality is not great for wild swimming in Lee Valley,

Maybe some spots between Teddington and Hampton Court if anyone is familiar with the area? Thanks!

Brockwell Park Lido (outdoor but not wild), Herne Hill/Brixton, allows children from ages 4-7 on a 1:1 audit:child ratio, and over 7 on a 1: 2 adult:child ratio.