HS2: Little Missenden residents' concerns at hole above tunnel

The mayor of Amersham said he thought the hole that opened up in the ground could be up to 10m (32ft) deep

People living and working near a large hole that opened up above a tunnel built for the HS2 high-speed rail line said they were "very anxious".

The opening beside Shardeloes Lake, close to Little Missenden in Buckinghamshire, appeared on Saturday above part of the Chiltern tunnel.

Mark Roberts, mayor of nearby Amersham, said people were "very concerned".

HS2 Ltd said the site had been sealed off and there was "no risk to the public".

The 10-mile (16km) Chiltern tunnel is the longest on the HS2 project, which is designed to improve links between London, Birmingham and the north of England.

The hole was likely linked to "pre-existing ground conditions", said the railway company

Mr Roberts said he thought the hole was about 6m (20ft) in diameter and at least 6m deep.

"It could be as much as 10m (32ft) deep... it's a big old chunk of soil that has collapsed into the ground," he said.

"Locals are very concerned... it's been of concern to people for years because underneath here is the Chiltern aquifer that supplies our drinking water.

"We've also got the River Misbourne that is a rare chalk stream and the lake. People have been concerned about the impact on those for years and this really ignites those concerns.

"It's a very popular walking area... the field itself is a public footpath and is also used by a farmer for exercising horses... what about if there were people there at the time?"

He said councillors had a scheduled meeting with HS2 next week, but he had asked for an immediate report on the situation.

Sanela Bejdic, from KoKo's cafe, said she felt "very anxious and worried"

Sanela Bejdic, who runs KoKo's cafe about 500 yards (457m) from where the hole opened up, said there was a lot of activity in the area on Saturday morning, but no-one would tell her what the problem was.

"I actually feel very anxious and worried that another sinkhole might appear," she said.

"[Both] residents and businesses, everybody is really worried about it.

"We would like HS2 to be transparent and let us all know exactly what is going on."

HS2 said the site had been sealed off and there was "no risk to the public"

The owner of Stepping Stones nursery, which is at the bottom of the footpath leading to the lake, said children aged two to five were walked to the area on a weekly basis.

Parvinder Jaspal said she had to reassure "very anxious parents" that the lake would "obviously be out of bounds" for the foreseeable.

"We go up to the lake a lot, it's a big part of what we do as not only is it a beautiful spot but the learning opportunities there are endless," she said.

"It's a shame and a worry for the parents that it's so close... could it happen nearer?

"Today we're thinking how is this going to affect the nursery - will it put parents off in the future?"

HS2 Ltd said the hole had appeared above part of the Chiltern tunnel

Buckinghamshire Council's Conservative leader, Martin Tett, said he had held an urgent meeting with senior HS2 directors to discuss the cause of the hole.

"I have said that we need complete transparency of the reasons and what learning has occurred as a result of this incident," he said.

"HS2 anticipate that the sinkhole will be 'remediated' within one to two weeks with backfill material and restored to farmland. We will obviously be watching this very closely."

'Full disclosure'

Sarah Green, Liberal Democrat MP for Chesham and Amersham, said that for years campaigners and local residents had "raised concerns about an event like this happening".

"It is vital that the Environment Agency and HS2 Ltd provide full disclosure as soon as possible, not just about this incident but about the steps they are taking to prevent any risk to the public and the environment," she said.

HS2 Ltd said it was engaging with the landowner and had notified the Environment Agency.

A spokesman added that investigations were ongoing, but it was likely linked to "pre-existing ground conditions".

Giant tunnelling machines have been excavating the high-speed rail project's route under the Chilterns in Buckinghamshire for the past 21 months.

The two tunnels, which are between the M25 and South Heath, have five shafts for emergency access and/or ventilation near Chalfont St Peter, Chalfont St Giles, Amersham, Little Missenden and Chesham Road.

They are part of the first phase of the route between London and the West Midlands, expected to begin operating between 2029 and 2033.