LDA Design and Jacobs are leading a HS2 project to create a new nature reserve in the Colne Valley, rewilding 127 hectares of arable land to create wood pasture, wetlands and flower-rich grassland using chalk taken from tunnelling under the Chilterns. The wildlife haven will use all 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, says that that it will be a distinctive landscape that replicates local chalk ridges. There are only 800 sq km of calcareous grassland left in England and this will be the largest site in the Chilterns.
“We aim to create a place for people to explore and connect with nature,” he said. “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 provide new connected green spaces and new footpath, cycling and horse-riding routes. It will create the kind of immersive and colourful environment that is special to chalk grasslands. It will potentially be colonised by hundreds of species of flora and fauna, including invertebrates, birds, mammals, reptiles and amphibians.
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.”
Finding the optimum soil profiles to support resilient, biodiverse grasslands is being researched in a study with Cranfield University and Tim O’Hare Associates.
The Western Slopes will sequester carbon and the concrete and limestone aggregate used in HS2’s construction will be recycled to add to the calcareous grassland, minimising HS2’s carbon footprint by reducing the removal of materials by truck.
Read Patrick Barkham’s article ‘Unique opportunity’ in The Guardian.
Image: Colne Valley Western Slopes – Grimshaw/Align
LDA Design and Jacobs are part of Align JV.