Hillingdon Council has commissioned two independent studies looking into the viability of an HS2 tunnel through the Colne Valley to reduce the impact of the high speed railway on west London.
The council has consistently asked that the whole route through the borough be tunnelled.
The council commissioned the reports from Peter Brett Associates (PBA) and Regeneris to look at the costs and benefits of tunnelling.
PBA’s report proposes a 7km tunnel between West Hyde and West Ruislip as an extension to the proposed Northolt tunnel, and argues that the junction with a spur to Heathrow can be made underground, with a total cost almost 6% greater than HS2’s current plan – an increase of around £67m.
Regeneris’ report seeks to value the economic, financial and environmental cost of HS2 on Hillingdon, and puts that between £41.9million and £157.5m.
HS2’s plan is for the trains to surface in West Ruislip and travel overground through the Colne Valley before entering the Chiltern Tunnel.
