Tideway seeks new 10-year partnership on ‘super-sewer’


Tideway is seeking a new partner to maintain its Thames Tideway Tunnel project for up to 10 years. 

Credit: Tideway.

The contract involves delivery of planned, preventative, and reactive maintenance services across 21 construction sites on London’s new ‘super-sewer’, with an estimated annual spend of around £7 million. 

“Tideway is looking for a provider to deliver […] maintenance services across the capital in accordance with maintenance plans for the ‘System Acceptance Period’ and possibly beyond,” said the company. 

Across a ten-year contract, the total value would be £70 million. 

Assets include but are not limited to: 

  • Near-surface civils  
  • MEICA equipment 
  • Building services 
  • Safety restraints  
  • Maintenance access hardware 

Deep civil elements – e.g. the main tunnel, connection tunnels and shafts – are outside of the scope of this contract. 

SCADA system and architecture and landscape are also not included. 


  • VINCI Construction Grands Projets, Bachy Soletanche, Costain (JV)  
  • Ferrovial, Laing O’Rourke (JV)  
  • Balfour Beatty, Morgan Sindall, Bam Nuttall (JV) 

Most of the construction work on the 15-mile super-sewer is now complete, the maintenance works are necessary for when the tunnel becomes operational under Thames Water, which is expected to be in the second half of 2025.   

Started in 2016, construction had been aimed for completion by next year, but was rescheduled owing to delays brought about by the pandemic.  

The major works project had, in 2014, initially been costed at around £3.5 billion.  

Credit: Tideway.

Earlier this year, however, a revised estimate revealed the cost to deliver the Thames Tideway Tunnel could now be £4.5 billion, after factoring in its remaining works programme and the cost of inflation. 

When fully operational, the new infrastructure could capture up to 95% of overflows from London’s sewerage network, improving the water quality of the Thames, and the environment. 

“Both the scope and scale of this work combined with the opportunity to work on one of the UK’s most important environmental projects represents a significant commercial opportunity to the market,” said the company. 

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