The Western Slopes rewilding project, located on land beside the HS2 high-speed railway in the Chilterns, is already attracting a variety of wildlife. The site, which is completely artificial and four years old, is due to open to the public next year.
The 127-hectare site, once a wheatfield, has been transformed into wildlife-rich grasslands, wet meadows, ponds, and small woods. It has seen the arrival of hedgehog clover, not recorded in Hertfordshire since 1878, alongside water voles, lesser emperor dragonflies, and pyramidal orchids.
The project has reused 10m cubic metres of chalk, topsoil, and subsoils excavated from the Chilterns tunnel. This approach has reduced CO2 emissions and construction traffic that would have resulted from dumping the material elsewhere. HS2 calculations suggest these grasslands could sequester 7% of the carbon impact of the entire high-speed line's construction.
The landscape has been sculpted into rolling “downs” using the excavated chalk, creating varied topsoils for a mosaic of habitats. Four cattle-grids have been installed, believed to be the first in Hertfordshire, to allow free-roaming cattle to graze within four separate compartments, a technique inspired by other rewilding sites.