Now we know why the ‘thermals’ were in full flow!

It’s the first time l have witnessed Bath’s thermal waters visibly draining into the River Avon from the edge of Parade Gardens – but now l know the reason why it was happening!

I know this hot spring water has passed through a Roman drain that has been doing its job for two thousand years.

It’s an ancient monument which carries water from the Sacred Spring and Great Bath with branches running from the King Spring and another from the Hetling Spring. They join under York Street before passing Bog Island and under Parade Gardens.

Seems yesterday – Tuesday, March 27th – was the day they decided to empty the Great Bath. Pulling the plug on 250,000 litres of hot water was enough to create a bit of a surge.

Stephen Clews, the Manager of the Roman Baths, told me:

‘The Great Bath was drained down yesterday for routine cleaning purposes, so this does explain what you saw.

It is drained down several times a year – usually at fairly short notice – as we fit it in between evening function commitments and other out of hours operational activities. We will probably drain down again in early June and then again in September.’

The operation is carried out to deal with the growth of algae and to take out anything visitors may have thrown into the water.

A similar cleaning operation was being carried out on the King’s Bath – formerly the Sacred Spring of the Roman builders of the baths and nearby temple.

Fellow Mayor’s Guide John Cooper snatched a couple of shots while he was visiting with a group. Thanks for passing them to us also John!

Bath’s hot springs have flown through the centuries. Rainwater falling on the hills around the city percolating down to a vast underground lake two miles beneath the surface.

Superheated by the Earth’s core it returns to the surface – under great pressure – through three cracks in the strata. You could fill a bath in eight seconds!