Work starts to 'save' Roman Baths in city of Bath
Work has begun in Bath to stop hot springs bursting to the surface and causing its Roman Baths to run dry.
Unless work is done, a geyser up to 26ft (7.9m) high may erupt, diverting water away from the Baths.
Rusting pipe work in an old borehole, which taps into Bath's springs, has resulted in underground water levels rising close to street-level.
A new borehole will be dug 246ft (75m) below ground to replace the old pipe work and safeguard the springs.
The water levels are normally three feet below the surface but have now risen up to three inches below the surface and the city council has said the area is in a "period of risk".
David Lawrence, from Bath and North East Somerset Council, said: "We've been working with our partners Wessex Water to sink a new borehole, the present Hetling borehole casing drills directly down into the soft material in which the water gathers.
"The difficulty with that is the well head is not secure in that material, with this solution we will be bedding the headgear into rock."
The borehole will be drilled at Hot Bath Street, at an angle of 13 degrees, so it intercepts the base of the Hetling Spring.
"The water that's coming up now fell on the Mendips 4,000 years ago, you don't just turn it off like a tap," said Mr Lawrence.
"We want to make sure we don't lose the hydraulic pressure [of the hot springs] because that feeds the King's Spring in the Roman Baths, it also feeds the Cross Springs and the Thermae Baths over the road here."
The new pipe is due to be installed later in the month with the project expected to be finished by early December.