The HS2 route in the Chilterns and the Colne Valley

High Speed Two (HS2) N North Portal Rd Intervention Shaft Vent Shaft Vent Shaft In design development In design development In design development In design development is the new high speed Next event Next event This event Next event North Portal – Design Event, Chesham Road Intervention Shaft - Little Missenden ‘You Said, Amersham – ‘You Said, We Did’, railway for Britain. Summer 2021 Design event, Summer 2021 We Did’, May 2021 Summer 2021

Chesham

What we are doing Align are working on behalf of HS2 Ltd Chilterns Area to build 22 kilometres of the high speed of Outstanding Amersham rail line, running between the Colne Natural Beauty Valley and the Chilterns. It includes the 3.4 kilometre long Colne Valley High Viaduct and the Chiltern tunnel with Chalfont Wycombe four ventilation (vent) shafts to regulate St Giles airflow, one intervention shaft and the shaft headhouses which contain electrical equipment. GREATER Our main works programme is now Colne Valley underway and we are holding regular Regional Park information events to share details Old Oak Euston on the progress of the designs, seek Common Station views and respond to feedback. Due to Station Covid-19 we have postponed all public face-to-face engagement events and Vent Shaft Chalfont St Peter Vent Shaft Colne Valley Viaduct South Portal/Western Valley slopes meetings, but we will continue to find Next event Next event Next event Next event Chalfont St Giles Vent Shaft - Chalfont St Peter Vent Shaft - Colne Valley Viaduct Western Valley Slopes new ways to involve the community. ‘Construction Update, ‘Construction Update, ‘Construction update, ‘Construction update, Summer 2021 Summer 2021 Summer 2021 Summer 2021 Introduction

Welcome to our ‘You HS2 route through the Chilterns

Said, We Did’ event for the Little Missenden vent shaft A413 Chesham Road Keepers Lane Intervention Shaft

Little Missenden In November 2020 we held an event to Vent Shaft share our plans for the Little Missenden vent shaft, the construction processes, Little Missenden Lane traffic management plans and the early Vent Shaft plans for the design of the headhouse. Now we would like to: Amersham Vent Shaft Chalfont St Giles N HS2 Tunnel • Show you the feedback that we have Vent Shaft received during design development, which has influenced our approach Chalfont St Peter The Little Missenden vent shaft will • Share the final designs we will be Vent Shaft provide air ventilation and access for seeking consent on from your local emergency services. It is located off the authority A413 to the east of Little Missenden. • Provide information on the construction of the vent shaft and headhouse • Show you how we plan to reduce the impact of our work on residents.

N 0 1 2 4km Public feedback

In November 2020, we held a public engagement event and you gave us feedback on four topics about our design. We asked you to rank our objectives in order of priority and provide comments. Your ranking of these objectives are shown below:

Landscape Ecology Design of the headhouse Construction • Respond to the character of the site • Protect existing wildlife species on the • Design a structure that blends into the • Return the wider construction site to and surrounding landscape site during construction landscape how it was before construction started • Use existing trees, hedgerows and new • Keep as many existing trees and • Reduce visibility of buildings • Reduce noise and vibration on the planting to conceal structures as far as hedgerows as possible • Keep the overall footprint (area) of the construction site possible • Restore the area using planting or compound as small as possible • Reduce HGV movements • Replace lost trees which must seeding of native and indigenous • Maintain a familiar scale and form to • Let people know when noisy works are be removed during construction, species local farm buildings occurring and keep residents regularly wherever possible • Create habitats that support as many • Reduce the operational impact of the updated • Consider the long term management species as possible (biodiverse) proposed structure • Minimise any visible impact of of the site and appearance of the new • Create habitats that are typical of construction landscape • Choose materials and detailing inspired the area but rare and declining – for by the local landscape • Minimise carbon footprint and reduce • Consider ways to enhance public example, chalk grassland the noise and air pollution across experience in places where people get • Create habitats that are integrated with construction fleet close to the site (for example from the the surrounding area diverted public footpath) Landscape

You said: “Respond to the character of the site and surrounding landscape” Landscape proposals Keeper’s Wood Public “Use existing trees, hedgerows and new planting to conceal Retained vegetation screens footpath structures as far as possible” views from the A413

We did: A413 Section A-A Maintain landscape character Screen buildings and compound

The landscape will be shaped to We will retain as much of the existing integrate with the profile of the valley vegetation along the A413 as possible, 6 edge, whilst woodland and shrub whilst planting substantial areas of native 2 planting and chalk grasslands will tree and shrub species to screen the 4 reinforce the rural setting. buildings and structures.

Key A N 1 Proposed woodland edge and 2 6 scrub planting areas 7 5 4 2 Chalk grassland 1 3 Temporary water body 5 7 4 Agricultural style fencing 3 1 compliments rural character A413 of the site 1 A 3

1 5 Profile of chalk valley retained Key A413 6 Reinstatement of public footpath Existing trees retained Proposed trees and vegetation 7 Site access from A413 Public footpath reinstatement

Landscape plan Illustrative view of the site Ecology

You said: “Consider the long-term management of site” “Restore the area using planting or seeding of native and indigenous species” 5

We did:

Propose new contextual habitats and prepare management plans

6 We will create connected habitats using 1 c native plants and seeds to enhance the biodiversity value of the site. HS2 will undertake long-term management of land in its ownership guided by b b a Habitat Management Plan for the lifespan of HS2. Our plans include: Creation of calcareous grassland habitat 1 3 1 2 reflective of Chilterns grassland Calcareous grassland (target habitat) 2 Retention and protection of existing habitat 6 a connectivity

New woodland edge and scrub planting used 2 3 Subsoil cap A413 4 to connect habitats, encouraging animal 3 foraging and movement Stones, branches, logs

4 Incorporation of habitat features such as: Gravel drainage layer a Hibernaculum Entrance points Key b Reptile Egg Laying Heaps Existing trees retained c Reptile and Invertebrate / Basking Bank Proposed trees and vegetation 5 Protection of Keeper’s Wood (ancient a Public footpath reinstatement woodland) - this will not be impacted by HS2 and is outside our site boundary Section - Typical hibernaculum Habitat creation proposals Headhouse design

You said: “The vent shaft should blend into the Chilterns landscape as far as Gently raised land possible to minimise the impact on our countryside” Agricultural courtyard arrangement We did: Agricultural fence and gate Arrange buildings in an agricultural compound layout Headhouse compound fence The arrangement of the buildings is 1 Central courtyard for access and based on an agricultural courtyard manoeuvring Above Ground Permanent access road layout, with the overall footprint of the 2 Doors accessed from the courtyard Infiltration basin compound kept to a minimum. 3 Primary elevation of each building faces into courtyard Existing trees retained 4 Ancillary structures kept low to reduce visual A413 clutter

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2 Basement box 2 Below Ground 1 3 Ventilation shaft 4 3 North and South running tunnels

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3D diagram - Building arrangement 3D diagram - Overall site arrangement Headhouse design

You said: “The proposed buildings must be sensitive to the environment and look to blend in with existing houses, farm dwellings“

We did: Took inspiration from the local historic and industrial agricultural buildings Pitched roofs wrap around the buildings, recessed and treated in a different creating simple agricultural barn forms. material, providing greater articulation to Buildings are orientated to reduce their the buildings. The louvred screen breaks perceived scale from key viewpoints. up the overall form and hides visual Door and ventilation openings are clutter associated with plant equipment.

3D diagram - Form and scale

Visualisation - Aerial view 3D diagram - Louvred openings Headhouse design

View looking west from lane through the trees

Key Plan - Location of view point

Visualisation - View from east (Year 1) Visualisation - View from east of site looking west (Year 15) Headhouse design

You said: “Can you reflect local building materials?”

We did: Use a simple palette of robust materials that blend in The zinc, painted steel and engineering The building colour and detail has been brick will be durable and designed to designed to blend into the landscape, age gracefully over time without losing using a simple palette of materials robustness and quality. Dark, neutral inspired by local agricultural and colours will ensure the buildings are industrial buildings. concealed as much as possible.

South east elevation

North east elevation Headhouse design

View looking north west from the A413

Key Plan - Location of view point

Visualisation - View from A413 (Year 1) Visualisation - View from A413 looking north west (Year 15) Headhouse design

You said: “The proposal needs to blend in with its surroundings” Visualisations

We did: Screen views of the building from the public footpath Where possible the compound has been 1 concealed from sight using planting and landscape earthworks. 2 3 Along the A413 and the public footpath, Key Plan - Location of view point Visualisation - View from public footpath (Year 1) existing and proposed trees conceal 4 most of the compound with topography partially screening the compound in distant views.

1 2

3 4

Sketches - Visibility sequence Visualisation - View from public footpath looking south (Year 15) Headhouse design

Family of headhouses

This headhouse is one of four which are located on rural farm sites within the Chilterns. These headhouses and the ancillary structures have been designed to blend into the existing landscape and form part of a common family of buildings. The buildings are distinguished by the colour of the painted horizontal Visualisation - Chalfont St Peter headhouse (Year 15) Visualisation - Chalfont St Giles headhouse (Year 15) Visualisation - Chesham Road headhouse (Year 15) louvres, selected to reflect the specific features of each site.

Chesham Rd

Little Missenden

Amersham Chalfont St Giles Chalfont St Peter

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Headhouse location map Visualisation - Little Missenden headhouse (Year 15) Headhouse design

Visualisation - Aerial view looking north west (Year 15) Traffic management and planning

We recognise that there are concerns regarding Little Missenden Vent Shaft Heavy Goods Vehicles using the A413 not only for Signalised junction Amersham Align but from our adjacent main works contractor, EKFB. The routes to each site are carefully planned A413 to reduce our impact on local communities. Holmer Amersham Green Vent Shaft You said: “Do not build a roundabout” “No impact on A413” Coleshill

Chalfont St Giles Winchmore Vent Shaft We did: Hill

During stages of high activity on site, such as D-walling, shaft excavation, ground A355 treatment and piling works, there will be an increase in Heavy Goods Vehicles (HGV) Chalfont movements from the site. There will also be periods where the need for HGVs will St GIles be lower. We are continuing to work with local stakeholders and share information about our trafc management strategies during construction.

We are: Seer Chalfont Green St Peter • Building a signalised junction to allow HGVs to safely access our site • Minimising the number of HGV movements by reducing the size of the vent shaft Beaconsfield excavation • Creating a Construction Consolidation Centre at the South Portal to act as a central A40 hub to manage all the deliveries out to our sites, cutting down the number of M40 vehicle trips made • Planning our HGV movements to avoid peak time wherever possible and holding them back so that only a certain number are on our logistics route at any one time. Map showing HGVs route to Little Missenden vent shaft site Construction site map

We will build the vent shaft as quickly and Keepers Lane safely as possible, and HS2 tunnels minimise our impact on Earthworks stockpiles Temporary construction the local community. fence (2.4 metre high)

Farmers access

Car park You said: “Return the construction Diverted public footpath site to how it was before Staff welfare block it started” and ofces Vent shaft and headhouse Security We did: Site main gate HGV wheel wash Material excavated from the site will Re-routed public foothpath be reused in the landscaping and Signalised junction restoration of the vent shaft site. The Trees removed for area around the vent shaft will be construction purposes landscaped to blend in with the contours of the existing area. Attenuation pond Once construction is complete all internal roads will be removed, apart from the access road to the head house A413 and the other buildings on the site. The signalised junction will be removed. Little Missenden Construction Programme

To minimise our impact on the local community, we will build the vent shaft and headhouse as quickly and safely as possible. Below is an indicative timeline of construction activities. We have highlighted those which may be more noticeable to local residents.

April 2021 July 2021 September 2021 March 2022 April 2022 June 2022 June 2023 April 2024 Site set up with Site preparation D-wall construction. Excavation of vent Shaft base slab. Construction of Tunnel Boring Construction of the internal haul roads, for Diaphragm Wall shaft. internal vent shaft Machines arrive headhouse and Visual impact: Noise impact: site accommodation (D-wall) construction. structures (floors and underneath the vent surface structures. Cranes, cutters, and Creation of vent shaft Short periods of and groundworks. access). shaft and connection Traffic impact: D-wall rigs may be connection with percussive piling will Electrical outfitting is established. Low. visible on site. tunnel prior to Tunnel occur. Earthworks and machinery Boring Machines and stockpiling installation. Noise impact: Traffic impact: arrival. activities. Extended Extended working This will be one of Landscaping. working hours may hours will be required. the busiest periods Noise impact: be required on some for site traffic with Short periods of days and weekends. increased HGV percussive piling will movements to and occur. Earthworks April 2025 from site for D-walling and stockpiling Construction concrete pours. activities. Extended complete. working hours may Noise impact: be required on some Earthworks and days and weekends. stockpiling activities at surface and D-walling concrete pours. Thank you

Thank you for viewing our online exhibition.

Next steps We will continue engagement with the local community to provide regular updates on the progress of construction.

Information events As part of our commitment to keeping you informed, we will be holding exhibitions and events for local residents. Due to the Covid-19 pandemic we are not currently able to hold face-to-face public events, to share information about the design and construction of the Little Missenden vent shaft. For more information and to find out how to receive regular updates, please visit: www.hs2inbucksandox.org.uk If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email [email protected] Little Missenden visualisation - Aerial view looking north west (Year 15)