Group take on HS2 in dam­age lim­i­ta­tion ex­er­cise

Buckinghamshire Advertiser - - NEWS - by Tom Her­bert tom.her­bert@trin­i­tymir­ror.com Twit­ter: @TRHer­bert

A GROUP of ex­perts, lo­cal politi­cians and con­cerned neigh­bours have lob­bied HS2 Ltd for a raft of mit­i­ga­tion mea­sures to lessen the project’s im­pact.

Cam­paign­ers called for a lower tun­nel depth, the pro­tec­tion of the River Mis­bourne and the im­prove­ment of the roads on which HGV traf­fic would travel around Lit­tle Mis­senden at a House of Lords Se­lect Com­mit­tee meet­ing held on Mon­day Novem­ber 7.

Rep­re­sent­ing cam­paign group Save St Giles, Rafael McDon­nell said at the meet­ing: “The orig­i­nal route pro­posed a line by­pass­ing the cen­tre of the vil­lage by a depth of 100 me­tres, but the new route comes through the heart of the vil­lage.

“The tun­nel as it passes un­der the cen­tre of our vil­lage is at a depth of 19 me­tres which we be­lieve, due to the ge­o­log­i­cal make up of the land around Chal­font St Giles, is not suf­fi­cient. Nine­teen me­tres is not much more than the length of this room.

“We don’t be­lieve the full im­pli­ca­tions have been as­sessed in terms of when this new route was put through the heart of the vil­lage and so we’re ask­ing for two things to be con­sid­ered.

“One, the route of the tun­nel is drilled deeper un­der­neath the vil­lage and, two, the river is safe­guarded to lessen po­ten­tial im­pact on the vil­lage and the en­vi­ron­men­tal im­pact.

“We be­lieve to date a lot of the work that had been done was based on desk-based re­search.

“We feel there’s not a thor­ough un­der­stand­ing of the area, of the makeup of the soil and the sur­round­ing land in our vil­lage.

“We feel that we can­not af­ford to wait and see, that some of the dam­age could be ir­re­versible.”

Dr Ian Cloke, vice- pres­i­dent of Tul­low Oil, giv­ing ev­i­dence as a wit­ness, said that HS2 had cho­sen a route ‘with­out suf­fi­cient study’, as the tun­nel would ‘badly im­pact’ both the River Mis­bourne and Chal­font St Giles.

He ar­gued the tun­nel should be built at a min­i­mum depth of 50 me­tres un­der­ground, say­ing the cur­rently pro­posed tun­nel depth of 19 me­tres was only 3.5 me­tres be­neath rot­ten chalk.

Dr Cloke said: “It’s not un­til 16 me­tres we get into solid chalk.

“It’s a very sen­si­tive in­ter­face. It is less than the height of a door be­fore we get into weak ground.

“I would be very wor- ried about that if I was run­ning the project.”

High­light­ing the lev­els of vi­bra­tion ex­pected from a ser­vice through which 18 trains per hour would pass, he said the tun­nel was only 200 me­tres from a listed church.

He added: “Ad­di­tional tun­nel depth be­neath the Mis­bourne is essen­tial.

“If we do this, you can mit­i­gate chalk col­lapse pos­si­bil­ity, it mit­i­gates risk of re­duc­tion of flow of the Mis­bourne, it mit­i­gates shal­low frac­ture risk and dam­age to build­ings, it’s deeper in the chalk and it’s away from nod­ules and eas­ier to drill.

“In­creas­ing depth be­low the Mis­bourne is sim­ple. We be­lieve it’s em­i­nently achiev­able and the ques­tion would be, why would HS2 not do it?”

Bob Older, on be­half of the Mis­bourne River Ac­tion Group, ar­gued that the pro­posed mit­i­ga­tion of the risk of loss of flow in the river due to tunnelling and vi­bra­tion of trains is ‘in­suf­fi­cient’.

He said: “The River Mis­bourne is very spe­cial. It is one of the Chilterns’ chalk streams – glob­ally rare there are fewer chalk streams in the world than there are gi­ant pan­das, and three quar­ters of them are in the UK.”

Mr Older ar­gued the river pro­vides spe­cial habi­tats, is a ‘much loved amenity’ and helps to de­fine the vil­lage ‘as the com­mu­nity that it is’.

He also ar­gued that suf­fi­cient mea­sures should be taken to pre­vent the river from sink­ing into the ground.

He said that HS2 ac­cepts a risk ex­ists and called for the use of Ben­tomat lin­ing – a geosyn­thetic clay liner – wher­ever the line crosses un­der the Mis­bourne for

Ad­di­tional tun­nel depth be­neath the Mis­bourne is essen­tial”

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.