Tideway, the company building London’s new super sewer, remains on track to deliver the project by 2025, following the most substantial review of the programme since 2018, according to its Interim Report and Financial Statements for the six months ended 30 September 2021 published this morning.

The Interim Operational Review for the period is for the Bazalgette Holdings Group.

The Group comprises Bazalgette Holdings Ltd, Bazalgette Tunnel Ltd (which trades under the name Tideway) and Bazalgette Finance plc. The principal activity of the Group is to design, build, commission, finance and maintain the Thames Tideway Tunnel.

The programme review, undertaken collaboratively by Tideway and key stakeholders including its main works contractors and Thames Water, looks at progress made on the project so far, taking into account the impacts of the Covid-19 pandemic, and provides an up-to-date picture of the future schedule.

The new sewer is designed to capture more than 95 per cent of the sewage spills that enter the river from London’s Victorian sewer system.

With the remaining tunnelling, secondary lining of the tunnels and shafts, and the connections to the Thames Water sewer network progressing well, the verified programme provides confidence the project will be completed in 2025.

Andy Mitchell, Tideway’s CEO, said:

“Working closely with our contractors and Thames Water has allowed us to look in detail at our progress so far and what we need to do going forward, to complete our project and start tackling sewage pollution in the River Thames as soon as possible.

“This comprehensive review has reaffirmed confidence in our programme as we reach the end of the tunnelling phases and look ahead to the testing and commissioning stage. We are fully focused on delivering the Tideway project safely, at the right quality and to best value.”

Sarah Bentley, Thames Water CEO, commented:

“This joint review of progress is a positive step forward in the delivery of the Thames Tideway Tunnel. Our teams are focused on working together to complete the project and bring the tunnel into service – so that it can do the vital job of improving the health of the river Thames and London’s environment.”

Tideway’s interim report confirms the programme review and the resulting c1 per cent increase in costs (£39 million). The project cost estimate is £4.2 billion and the estimated £20-£25 annual cost range for Thames Water bill payers remains unchanged.

Total project costs for the six-month period were £365.4 million (2020: £316.8 million), taking the total capitalised costs relating to the tunnel at 30 September 2021 to £3,596.5 million (2020: £2,910.7 million).

Key achievements in the period included the completion of shaft excavation on all sites and completion of 9.8km of tunnel secondary lining. Almost 24km of the new tunnel system has now been excavated under the River Thames.

Tideway has also started the process of handing back areas where it has finished work, with a section of land at Hammersmith Pumping Station having been successfully handed back to a residential developer.

Click here to download the Interim Report & Accounts