The company behind Britain’s new high-speed railway has revealed how progress to recreate over 100 hectares of chalk grasslands is helping wildlife to thrive around the southern portal of its tunnel beneath the Chiltern Hills.
The tunnel, near Maple Cross, was completed in March 2024 and is the longest in the Hs2 development.
A new video shows how habitat is being created on London’s north-western edge with three million tonnes of chalk excavated during construction of the line’s 10 mile long tunnel.
Environment manager Alice Williams said: “Chalk grasslands are unique to south east England, but the area they cover has been shrinking for centuries because of reasons including population growth and farming.
“They support a wide variety of wildflowers, insects, birds and animals, and are crucial for an area’s biodiversity, so when an opportunity comes along to add to the total chalk grassland area – in this case HS2’s Chiltern Tunnel – it needs to be seized.”
The scheme, known within the HS2 programme as the Colne Valley Western Slopes project, will see 127 hectares of former agricultural land restored to biologically diverse grassland, reminiscent of the rare chalk downlands that are found in pockets across the Chiltern Hills.
Laying either side of the railway, the newly landscaped area straddles the Buckinghamshire-Hertfordshire border. It is being seeded with a variety of plants that thrive in chalky soils including kidney vetch, greater knapweed and sainfoin.
Wildlife thriving near Maple Cross. (Image: HS2)
More than 50,000 trees native to southern England will be planted. In particular, the project’s landscape architects are seeking to create new beech tree dominated woodland, which is characteristic of the Chilterns, as well planting declining native species such as box and juniper.
Now in the second year of its three-year landscape creation phase, the new habitat is developing well, supporting a wide variety of flora and fauna.
Birds including yellowhammer, skylarks, red kites and a breeding pair of little ringed plovers are regular visitors to the area.
The site is also home to at least 10 dragonfly species including the emperor and scarce chaser as well as red-eyed damselfly and rare butterfly species including the marbled white and the Essex skipper.
(Image: PA) Once the grassland and planting areas are well established, the hope is for the land to be managed with low-impact methods such as conservation cattle grazing.
Some areas, including its cycle paths, bridleways and viewing points will be open to the public to enjoy by the time HS2 is operational.
Watford area residents are set to benefit from the improvements to capacity between London and Birmingham, but commuter groups have claimed cuts to the overall project could leave locals with few material benefits.
Green Belt groups have also criticised the schemes impact on the environment.