HS2 has announced a new "ambitious" scheme designed to enhance the environment near two major tunnels it is constructing.

Bosses of the multibillion pound high speed railway say they want to create 127 hectares of new chalk grassland, woodland, wood pasture and wetland habitats.

Labelled the Colne Valley Western Slopes project, HS2 says the scheme is the "biggest single landscape and habitat creation project within HS2’s Green Corridor programme".

The plans near West Hyde on the Hertfordshire and Buckinghamshire border includes the planting of almost 65,000 trees and shrubs of 32 species, with nearly 3.5km of new hedgerows.

Around 90 hectares of chalk grassland will be established, along with new green spaces, and around 4.5km of new footpaths, cycling routes, and horse-riding routes.

CGI of a viewing point of the Colne Valley Western Slopes

CGI of a viewing point of the Colne Valley Western Slopes

Colne Valley Western Slopes Tilehouse Lane Viewing Point. Credit: HS2

Colne Valley Western Slopes Tilehouse Lane Viewing Point. Credit: HS2

HS2 says land that is initially needed for a major works compound to construct the Colne Valley Viaduct and ten mile Chiltern Tunnels will be transformed through the re-use of existing soils and recycling of three million m3 of chalk taken from the tunnel excavation, as well as concrete and limestone materials used in the construction process.

The project is being designed and delivered by HS2’s civils contractor Align, with full plans shared with the community later this month.

Colne Valley Western Slopes. Credit: HS2

Colne Valley Western Slopes. Credit: HS2

HS2’s environment director, Peter Miller, said: "This project forms a major part of HS2’s Green Corridor programme to establish better connected, sustainable and biodiverse landscapes along the route of the new railway that will contribute substantially to HS2’s carbon reduction target.

"It demonstrates HS2’s approach to addressing many of the complex issues surrounding climate change and which are central to protecting our environment, and is a great example of how good design and planning can mitigate the effects of climate change."

Colne Valley Western Slopes. Credit: HS2

Colne Valley Western Slopes. Credit: HS2

New walking and cycling routes are proposed within the Colne Valley. Credit: HS2

New walking and cycling routes are proposed within the Colne Valley. Credit: HS2

Daniel Altier, project director from Align, added: "This innovative, multi-discipline project is designed to create a huge expanse of new grassland, connected woodland and wood pasture in the Colne Valley, helping to preserve declining or rare flora and fauna in the area, and providing a lasting legacy for biodiversity and local people.

"We are pleased to be collaborating on the design with Natural England, Hertfordshire and Middlesex Wildlife Trust, the Colne Valley Regional Park Panel, local authorities, and specialist soils experts."

Two webinars detailing the final plans are set to take place at 12.30pm on March 23 and at 6.30pm on March 25.

Members of the public can register for the webinar on Eventbrite here.