This is HS2 Ltd’s report to government on the outcomes of our studies into, and recommendations for, potential line of route alignment changes to HS2 London to West Midlands in response to issues raised during consultation. We used these to develop a programme of local studies to consider options for mitigating impacts and enhancing the line of route. The ‘High speed rail: Investing in Britain’s future consultation’ was launched on 28 February 2011 with a closing date for responses of 29 July 2011. That consultation covered both the government’s strategy for high speed rail, and the proposed line of route for phase one from London to West Midlands.
Balancing engineering issues, environmental issues, costs and benefits we recommend that, if a decision is taken to proceed with HS2, the following changes be considered for inclusion in the line of route to be taken forward to preliminary design and Environmental Impact Assessment (EIA):
- increase the clearance of HS2 over the Trent and Mersey Canal near Lichfield to ensure that it remains navigable. We also recommend a slight alteration to the alignment to ensure that it would be compatible with a future extended high speed network
- move the route slightly further away from Middleton to reduce local impacts
- a shallower cutting and longer green tunnel at Burton Green to further mitigate local impacts and reduce spoil generation
- mitigation of impacts on Balsall Common
- move the route slightly further east to avoid Kenilworth Golf Club, lower it further into cutting through the National Agricultural Centre, and introduce a retained cutting through South Cubbington Wood to reduce impacts on this ancient woodland
- introduce a longer bored tunnel at Long Itchington Wood
- introduce a longer green tunnel past Chipping Warden and Aston le Walls, and to curve the route to avoid a cluster of important heritage sites at Edgcote
- lower the alignment and introduce a green tunnel past Greatworth, and a short green tunnel at Turweston
- move the route further away from Twyford
- lower the alignment past Aylesbury and Stoke Mandeville to reduce local impacts and eliminate the need for larger scale works to local roads and the Chiltern Line
- introduce a longer green tunnel to reduce impacts around Wendover, and an extension to the green tunnel at South Heath
- introduce a longer, continuous tunnel from Little Missenden to the M25 through the Chilterns AONB to reduce the need for deep cutting and to avoid an aquifer
- introduce a 2.75 mile (4.4 kilometre) bored tunnel along the Northolt corridor to reduce impacts on local communities and avoid major works to the Chiltern Line
Taken together we consider that these changes would be a considerable enhancement to the consultation route. The number of properties that would be at risk of land take, either during or after construction, would be reduced. Noise impacts would be substantially lower. It would result in a small reduction in the number of properties that would be demolished, and a much larger reduction in the number that would be at risk of land take. There would be reduced impacts on communities and the landscape of the Chilterns AONB due to an increased length of tunnelling and green tunnels, while the adoption of additional green tunnels elsewhere along the route would reduce impacts on the landscape, biodiversity and local communities. Through the Chilterns AONB this would mean that seven and a half miles would be in tunnel or green tunnel. More than three and a half miles would be hidden in deep cutting, reducing visual impacts, meaning less than two miles would be visible.
These improvements can be achieved without impacting on journey times and with an overall reduction in construction costs compared to the consultation route.
Although the studies have identified an opportunity to improve the route in a number of places at this stage, this would not be the final opportunity to refine or mitigate the route. That would finally be decided through ongoing engagement as part of the EIA and through the hybrid bill process in Parliament. If a decision is taken to proceed with HS2 along this route we would use consultation responses to support preliminary design and inform the development of mitigation measures along the length of the route.
Paragraph 4.3.11 on page 33 has been amended to clarify that the figures in the rest of the paragraph relate to the route within the Chilterns AONB, and not between Wendover and the M25 as the original report suggested. An incorrectly hyperlinked reference on the copyright page has also been corrected.
Paragraph 4.3.6 on page 31 has been amended to to clarify that the depth of the cutting has been reduced between South Heath and Wendover Dean, and not South Heath and Little Missenden as the original report suggested.