Landscape; and Water environment

Heathrow expansion provides the opportunity for positive change in the landscape around the airport. Our Landscape Strategy is driven by the ambition of Heathrow to become one of the most sustainable airports in the world, and to become a great place to live, work and travel.


To achieve this positive change, our Landscape Strategy encompasses three core themes to deliver a smarter, brighter and greener Heathrow.

Green Loop and open spaces

We are proposing a Green Loop which is a roughly 20km route around the airport, made up of existing and proposed footpaths and cycleways which join up with additional routes and landscapes.

The Green Loop connects open spaces, communities and functions as a wildlife corridor in places.

Green and blue Infrastructure

Heathrow sits between the natural floodplains of the Colne Valley and Crane Valley, which form corridors made up of woodland, meadows, wetlands and watercourses connected with the wider landscape linking the Chilterns with the River Thames.

Our proposals include reclaiming former landfill sites, increasing tree planting, providing flood storage areas and improving accessibility to the countryside. This will create enhanced, better connected and more resilient blue and green infrastructure, to improve the visual landscape and public green spaces for our local communities.

The airport boundary

Where affected by our expansion proposals, the boundary of the airport will be carefully designed to improve the overall appearance of the airport and help it integrate into the surrounding area.

To the west and south the relocated rivers will create a natural edge between the airport and the M25.

In the north, a large earth embankment may combine noise mitigation and visual screening.

To the south, the boundary will include airport supporting developments such as hotels, offices and cargo facilities.

What is green and blue infrastructure?

Green and blue infrastructure refers to the aspects of the landscape that could form a green-blue network. The green landscape is made up of aspects such as hedgerows, woodlands and fields whereas the blue landscape is linked to water such as ponds and lakes.

Water environment

The expansion of Heathrow will extend the airport into the Colne Valley, affecting the routes of a number of watercourses and areas of existing floodplain. We plan to address our effects by creating opportunities for significant enhancements.

Our proposals seek not only to protect the quality of the water environment but also ensure no increase in flood risk for local communities.

Click on the expandable sections below to find out more about each aspect.

River diversions

Several rivers and smaller streams will need to be diverted, realigned or bridged. There will be no diversions of the River Crane.

Wraysbury River, River Colne and Bigley Ditch

The Wraysbury River, River Colne and Bigley Ditch will join together north of Harmondsworth Moor and pass under the airfield in one channel through a covered river corridor to the east of the existing M25. South of Bath Road, the Wraysbury River will split from the River Colne and travel west under the existing and new M25.

The River Colne will pass under the Southern Perimeter Road before connecting back to its existing channel north of Stanwell Moor.

The Duke of Northumberland’s River and Longford River

The Duke of Northumberland’s River will be combined with the Longford River and will pass under the airfi eld in one channel through a covered river corridor parallel to the combined Colne/Wraysbury channel.

The Colne Brook

The Colne Brook will be diverted around the northern side of the Thames Water sewage treatment works and the northern and western side of the railhead/logistics centre, before returning to its existing channel north of Colnbrook village.

Flood storage

Without mitigation, expansion will result in the loss of flood plain in the catchment of the River Colne and Colne Brook. We are committed to ensuring that no homes or businesses are at greater risk of flooding because of the Project, so we will replace the lost flood storage to achieve this.

Flood defence works will also be carried out on the channels through Colnbrook village to manage the risk of flooding.

Drainage and pollution control

Flood storage and water quality treatment areas will be put in place.