The company that builds the HS2 high-speed rail line has confirmed it is investigating the occurrence of a sinkhole near a Buckinghamshire river, which has been identified as “quite sizeable” in correspondence seen by The Guardian.
The sinkhole is near Lake Shardeloes, near Amersham, and an email sent to local residents by an official from HS2 Ltd contractor Align on Saturday night said: “It is quite large – around six meters in diameter and five meters deep. These are approximate measurements.”
The sinkhole is at Bazzards Field, southwest of the lake. It is near a public right-of-way and has been fenced off.
The email adds: “Owners have been informed and cattle have been moved to safety.”
HS2 Ltd sources said the area is over a completed tunnel section so tunneling operations are continuing. They said the Environment Agency had been notified and that HS2 was engaging with the owner.
The drain is the latest problem to affect the construction work of HS2. There were three separate incidents involving “bubbling pools” between February and April and other issues at Ruislip.
The Birmingham to Crewe section of track has been delayed and project costs are skyrocketing.
Paul Jennings of the River Chess Association, which oversees HS2’s work and campaigns for clean water, said he had contacted the Environment Agency after the sinkhole appeared and urged it to halt any further work. until it has been investigated. He said he had also contacted Thames Water and asked them to stop supplying water to HS2 in the area until an investigation was carried out.
“We’ve been predicting something like this would happen for the last 10 years,” Jennings said. “We’ve been giving a consistent message to HS2: ‘Don’t tunnel through the chalk, it’s unstable.'”
After images of the sinkhole surfaced on social media, anti-HS2 activists have been Messenger service HS2 on Twitter saying “Time to stop digging”.
An HS2 spokesperson said: “We are aware of a small area of earthwork within a field above the Chiltern Tunnels. Investigations are ongoing, but this is likely related to pre-existing ground conditions above the tunnels. The site has been sealed and there is no risk to the public.”