London’s super sewer Thames Tideway Tunnel facing cost pressures

The construction of London’s super sewer has hit cost problems due to a catalogue of engineering challenges, the project’s holding company has confirmed.

Several cost pressures have been identified on the Thames Tideway Tunnel project, with total project costs for the six months to the end of September hitting £325.3m and bringing the total cost so far to £1.48bn.

Holding company Bazalgette said: “Following significant progress on the project and now having mobilised on 20 of our 21 sites, Tideway has identified several cost pressures in the programme…to mitigate the cost pressures Tideway has begun to implement cost saving measures in partnership with our contractors and remains focussed on achieving the baseline target.”

Saving measures outlined in the firm’s half-year results include eliminating overlap, taking measures to increase productivity, value engineering and delivering overhead savings.

The areas causing problems are engineering challenges at Blackfriars, construction at King Edward Memorial Park and Albert Embankment and challenges in shafts at east area sites.

The 25km tunnel, which is expected to be completed by 2023, is budgeted to cost £4.2bn overall.

It was given planning permission in 2014 and has been designed to help the capital cope with the demand of its growing population.

Running from Acton, west London, the tunnel will run underneath London and transfer waste to the east at Beckton Sewage Treatment works.