News on HS2 in Herts

Over the last 18 months works have been progressing at the South Portal site off Chalfont Lane & Tilehouse Lane. This is where the Colne Valley Viaduct and the Chiltern Tunnel will be built from. In October we will start early works, including earthworks for the tunnel portal and the creation of compound facilities.

What is happening?

The site is being prepared for our future engineering works. Between September 2019 and January 2020 we will be excavating the cutting for the tunnel portal, creating an embankment (bund) to the north of Chalfont Lane to screen the works for residents and building platforms for temporary, two storey, site facilities. This will include offices and welfare facilitates for our staff on site. Other works will include creating drainage ponds and ditches, and installing utilities and services for the buildings. We are also installing vehicle wheel washing facilities to prevent mud and dirt being taken onto local roads. Additional hoardings and fences will be installed.

How will this affect me?

Heavy goods vehicles (HGVs) will in the main use the dedicated M25 slip roads that we have built. Other traffic accessing the site will use the A412. We will do all we can to keep this traffic to a minimum. You may notice the movement of large earth-moving equipment within the site as our works progress.

You can find more information on these works in our notification .