Search site
Chiltern District Council
Search site

HS2 - Campaigners launch their case for 'Going Underground' to preserve AONB

A new study launched on Friday 25 April proves the viability of a 24.7km tunnel, which would preserve the protected Chilterns Area of Outstanding Natural Beauty.

The study, produced by Peter Brett Associates, has been commissioned by Chiltern District Council, in association with Aylesbury Vale District Council, Buckinghamshire County Council and the Chilterns Conservation Board.

It proposes a revised Green Route, all in tunnel, which goes under the River Misbourne at Chalfont St Giles as far as the A404.

The route then follows a line east of Little Kingshill and west of Little Missenden to cross under the River Misbourne, Chiltern Line and A413. It then runs parallel to the A413 passing to the east of Great Missenden with an intervention gap close to the A413 south of Bowood Lane. This is close to existing transport routes, lessening the effect of this open section. Access to the required gap for emergency purposes is accessible from the A413 and will be entirely underground.

The government's current proposed route takes HS2 through the widest part of the Chilterns AONB, which the report states will 'militate rather than mitigate the impact'.

Benefits of this new proposed Green Route include:

  • Significantly less impact on the environment and communities in the Chilterns AONB
  • The route offers better operational alignment and passes through better and more consistent ground conditions below the water table
  • With a gradient of less than one per cent, energy requirements and wear on the tracks would be reduced. The government's current proposed route has a gradient of three per cent
  • The Green Route avoids Bacombe Hill, near Wendover, which is the area of greatest slope instability
  • Logistically, tunnelling could start at both ends of the tunnel with worksites located at either end minimising disruption to exiting transport infrastructure
  • Chalk slurry from boring can be transported long distances by pipeline before treatment and reuse, reducing cost and impact of transportation
  • Chalk spoil from open excavations could be used as construction fill material

The cost of the Green Route is estimated at £1.85bn, representing 1.5-2 per cent of the overall construction cost of HS2 Phase One; however, this should be viewed with the considerable mitigation of the effects of the route on the Chilterns AONB and would avoid extensive compensation costs, which have not been factored in at this stage.

Permanent and irretrievable loss of environment on the government's current proposed route is rated 'very high' - and as this latest report demonstrates, is avoidable. As the report states, the technology is available, engineering solutions exist. The question now is whether a small additional financial cost at construction stage, set against savings across the project's whole life, is worth preserving a beautiful and unique part of the countryside.

In a recent poll in Countryfile News, 93 per cent of respondents said HS2 should not be built.

In the recent responses to the Environmental Statement, a continuous tunnel was the most preferred mitigation measure.

Those whose livelihoods and communities are threatened by HS2 are in no doubt. The Chilterns AONB is priceless, and if the project does go ahead £1.85bn is a small price to pay to preserve this unique landscape, in a scheme likely to exceed £50bn.

Rt Hon Cheryl Gillan, MP for Chesham and Amersham, said: "If HS2 is to go ahead, any government responsible for this project should provide the maximum protection for the AONB through a full tunnel. This special environment is valuable for future generations and should not be destroyed where extra tunnelling could provide a solution to its safeguarding."

Leader of Chiltern District Council, Nick Rose: "HS2 would create a huge and ugly scar through parts of the AONB. Our proposal represents a huge improvement over the existing government proposed scheme and avoids the reckless damage that the rail line would cause."

Steve Rodrick, Chief Officer at the Chilterns Conservation Board said: "The Chilterns AONB is natural heritage and we expect those responsible for designing the HS2 railway to protect this special place. A long bored tunnel is the only acceptable solution."

Martin Tett, Leader of Buckinghamshire County Council, said: "The Chilterns are a nationally-designated Area of Outstanding Natural Beauty and a treasure for the whole country. Protecting and enhancing them is one of our key responsibilities we owe to future generations."

Councillor Neil Blake, Leader of AVDC, said: "While we accept that investment in our rail infrastructure is required, I don't feel that the proposed HS2 project is the best use of public money, nor is the cost of damaging irreplaceable natural heritage acceptable. However, if the project is to go forward, I urge the government to consider our alternative tunnel options that help to avoid permanent environmental damage."

Final Report of High Speed Rail in the Chilterns Tunnelling Options and associated maps and drawings

pdf icon Final report of High Speed Rail in the Chilterns Tunnelling Options [1Mb]

Tunnel Maps

1.pdf icon Tunnel map 1 - long sections [114kb]

2.pdf icon Tunnel map 2 - route alternatives [215kb]

3.pdf icon Tunnel map 3 - route plans [229kb] (recommended route)

4.pdf icon Tunnel map 4 - intervention gap locations [192kb]

5.pdf icon Tunnel map 5 - Northern portal locations [178kb]

pdf icon 30067_001_011B [24Mb]

pdf icon 30067_001_012 [1Mb]

pdf icon 30067_001_013 [451kb]

pdf icon 30067_001_014 [299kb]

pdf icon 30067_001_015 [12Mb]

pdf icon 30067_001_016 [286kb]

pdf icon 30067_001_021 [1Mb]

pdf icon 30067_001_022 [1Mb]


The Bill provides that the railway will be constructed within the Chilterns AONB from its southerly border, to the north of Chalfont St Giles, up to the border between Chiltern and Aylesbury Vale Districts. The AONB is an area of considerable sensitivity and where the railway is above ground it would dissect areas of ancient woodland and high quality landscape leaving a permanent feature upon one of the most attractive areas in Buckinghamshire.

If you would like to support the Chiltern District Council petition for the alternative tunnel option, use of the following wording is suggested:

[Add a sentence or two about why the AONB is special to you]

"Your petitioner respectfully requests that your honourable House should pay special attention to the proposals in the Bill so far as they affect the AONB in order to determine whether due regard has been paid to this highly sensitive area and whether the proposed railway is appropriate in light of its adverse impact on the area and its residents and businesses.

Your petitioner supports the Chiltern District Council's proposals for an extended bored tunnel throughout the AONB, which in your Petitioner's opinion would alleviate the detrimental impact that the proposed railway will otherwise have on the AONB."