LDA Design and Jacobs are managing a HS2 project to create a new nature reserve in the Colne Valley, restoring 127 hectares of arable land to create wood pasture, wetlands and flowered grassland using chalk from tunnelling under the Chilterns. It will use three million tonnes of chalk excavated from a 10-mile tunnel.
Simon Railton, a director at LDA Design and landscape architecture lead for the project, said that it will be a distinctive landscape the recreates local chalk ridges. There are only 800km2 of calcareous grassland left in England and this will be the largest site in the Chilterns.
“Our design team is passionate about achieving an enduring environmental legacy for the project and addressing some of the biggest issues of our time around climate change and biodiversity loss.”
The Western Slopes project will deliver new connected green spaces and new cycling, footpath and horse-riding routes. Creating an environment that will hopefully be colonised by hundreds of species of flora and fauna, including invertebrates, birds, mammals, and reptiles.
Plant species and habitats are being carefully selected to be resilient to a changing climate. Almost 65,000 trees and shrubs of 32 species will be planted together with nearly 3.5km of new hedgerows. Around 90 hectares of calcareous grasslands which once thrived on the valley slopes will be established and areas of historic woodland reinstated.
Matt Hobbs, the lead ecologist from Jacobs, said his team had been inspired by a visit to the rewilded Knepp Estate in West Sussex. “This is a rewilding project, creating diverse habitats rather than targeting species. We hope that eventually, when areas are robust enough, the local land managers will introduce nature’s best engineers – free roaming large herbivores, grazing all year round.”
The Western Slopes will help cut carbon by reusing materials and the concrete limestone aggregate used in HS2’s construction will be recycled to add to the calcareous grassland. This will minimise HS2’s carbon footprint by reducing the removal of materials by truck.