The mysterious hole which opened up on a street in Tring has been filled and there is ‘relief’ it did not turn out to be more dangerous.
Nick Hollinghurst, Herts County Councillor for Tring, was travelling past Bunyan Close when he noticed work being done to explore a potential swallow hole.
Ringway engineers were called in to carry out a survey and decided that the two-metre wide hole was safe to be filled with concrete foam.
As photos spread, residents expressed their concerns on social media but the cul-de-sac was resurfaced and reopened to cars on Monday.
The county council said Thames Water is finalising its report but it appears the collapse was caused by ‘water under the road’.
“We’re all very relieved,” Mr Hollinghurst said. “I was very worried that it was going to turn out to be one of those sink holes, or swallow holes as they call them.
“But it became quite clear that this one was on a much smaller scale.
“It doesn’t have the same mechanism as a sink hole.
“A survey was carried out, with cameras, to find out what exactly happened.
“I don’t know what the results were but they were obviously results they were happy with because it was decided that it was safe enough to refill it.”
He added: “There hasn’t been one like this before, to my knowledge.
“But we have to remember that the geology here means we have surface clay with chalk underneath and chalk can dissolve to form a cavity.
“This happens to be a very minor problem.”
The hole was identified on Friday and Ringway engineers were on site to investigate.
Thames Water workers arrived at 1pm with specialist equipment for surveying pipework and underground cavities.
But Mr Hollinghurst was disappointed that there was a ‘near five-hour delay’ before arriving with the necessary specialised surveying equipment.
A spokesman for the county council said: “The work has now all been completed and the road has been reopened.
“Thames Water did a survey and found the sewer was in tact but some water had got under the road and part of the road had collapsed.
“Foam concrete was used to back-fill the hole and the road was resurfaced before it reopened on Monday.”