“It’s probable that the sinkhole is due to a burst water main flushing out weak unconsolidated sands from beneath the road over a period of time, creating a cavity which then collapsed when it got big enough,” Farrant said.
A leaking pipe could have weakened the rock and led to the collapse of a mine, if one extended under the road, though it’s possible that a mine roof collapsed and broke the water main.
That could happen if someone dug a large hole below the local water table, or if there was heavy rainfall, flooding or a sudden ingress of water from a burst pipe.
“The high pressure water from the damaged pipe likely ‘boiled’ the sandy soil beneath the surface, creating cavities that led to the ground collapsing,” he said.
Maps published in 1872 reveal an entrance to an old sand mine very close to the site of the Godstone sinkhole, Farrant said.
