Thames Water has gone out to tender this weekend for the construction of its £4.2 billion Tideway Tunnel contract. Full tender documentation is available to download from the waterbriefing website - see below for details.

The works and services to be provided will be undertaken in London across circa 21 sites from Acton in the West to Abbey Mills in the East, along and underneath the River Thames and connecting with Lee Tunnel (currently under construction).

The contract(s) are for the design, construction, commissioning and (during the caretaker period) maintenance of the Thames Tideway Tunnel and are separated into 3 Lots of 3 separate Contracts as follows:

Main Works - West –main tunnel drive including shafts and connections – Carnwath Road Riverside to Acton Storm Water Tanks and long connection tunnel drive – Frogmore;

Main Works - Central - main tunnel drives including shafts and connections –Kirtling Street to Carnwath Road Riverside (West) and Kirtling Street to Chambers Wharf (East); and

Main Works - East –main tunnel drive including shafts and connections - Chambers Wharf to Abbey Mills Pumping Station and long connection tunnel drive – Greenwich Pumping Station to Chambers Wharf.

The estimated indicative range value of each Lot (excluding VAT) is:

1. Main Works – West - £300 million - £500 million
2. Main Works – Central - £600 million - £950 million
3. Main Works – East - £500 million - £800 million

The Thames Tideway Tunnel Project comprises:

• wastewater sewers and tunnels;
• design, construction, commissioning, operation, financing and maintenance of the main tunnel and connection tunnels;
• CSO drop shafts, short connection tunnels and associated development to intercept flows and divert them into the main tunnel or connection tunnels;
• works to modify Thames Water's existing pumping stations and sewers;
• associated development to facilitate construction of the tunnels and shafts; and
• any other works and/or services deemed necessary to deliver the Thames Tideway Tunnel Project

The 6.5-7.2 m-diameter, 25 km-long main tunnel between Thames Water's existing operational sites at Acton Storm Tanks and Abbey Mills Pumping Station would control untreated sewage from 34 CSOs identified as ‘unsatisfactory' by the Environment Agency. Sewage flows captured in the Thames Tideway Tunnel are intended to be transferred down the Thames Tideway Tunnel route for pumping out and treatment at Beckton Sewage Treatment Works via the Lee Tunnel.

The long connection tunnels are known as the Frogmore connection tunnel (2.6m-diameter and 1.1 km-long) and the Greenwich connection tunnel (5m-diameter and 4.6 km-long)

Contractors will be required to design, build and/or procure equipment including tunnel boring machines and diaphragm walling equipment to construct the relevant sections of the Tunnel.

Key objectives for the delivery of the Tideway Tunnel include ensuring highest quality construction, current best practice with regards to the safety regime and full consideration for whole life maintenance costs in selection of materials and construction techniques.

The tender documents also state that applicants should also be aware that a key aspect of the Project is to ensure that the Contracting Entity's legacy strategy is implemented. The new Water Industry (Specified Infrastructure Projects) (English Undertakers) Regulations which came into force on 27th June 2013 enable the Secretary of State or industry regulator Ofwat to specify by notice when a significant infrastructure project would require a separate Ofwat-regulated infrastructure provider to finance and deliver the project. The key themes in the legacy strategy and the legacy requirements are described in the Pre-Qualification Pack.

The scope of the works and services to be carried under the contract includes the following:

• design works;
• enabling works;
• temporary works;
• construction works;
• tunnelling and spoil removal;
• marine transportation and logistics;
• ground stabilisation and treatment works;
• utilities diversions;
• MEICA;
• SCADA;
• structural engineering works;
• civil engineering works;
• protection of third party assets;
• access control and security services;
• occupational health services;
• connections to the Lee Tunnel (East Lot only); and
• such other works and/or services as are necessary to deliver the Project including (but not limited to) obtaining and maintaining all necessary post-DCO consents, undertaking works and services to implement agreed legacy strategy and stakeholder management.

Applicants will be able to express their interest in one, two or all three Lots. However, Thames Water says that the Contracting Entity iwill not award any Tenderer (Contractor/Consortium/Relevant Organisation) more than one Lot unless Exceptional Circumstances apply due to the following reasons:

• complexity of the works required to successfully deliver each of the Lots
• the capital value of each of the Lots
• the requirement for resilience and security
• the need to manage and mitigate the risks associated with the delivery of the whole programme within the scheduled project completion date
• the need to ensure overall deliverability of the Project.

The rationale for this strategy is that (i) it will maximise competition, improve resilience of the Project to the default or insolvency of one of the Contractors, avoid over dominance of one Contractor, bringing benefits to the overall delivery programme and cost efficiency; and ensure the applicability and workability of the alliancing mechanisms and incentivisation mechanics.

Thames Water has also set out in detail the circumstances in which it reserves the right to award more than one Lot/Contract to a Tenderer, the right not to invite any Applicants to tender for the West or East Lot and to abort the procurement of the West or East Lot and subsequently re-procure it or to incorporate the West or East Lot within the Central Lot.

Starting date for the contract is 13.5.2015 with a completion date of 28.3.2023. Both single entities or consortia will be able to submit expressions of interest and tenders. 

Time limit for receipt of requests for documents or for accessing documents is midday on 12.9.2013 and the time limit for receipt of tenders or requests to participate is 13.9.2013.

The Contracting Entity also reserves the right to amend dates and deadlines and to update the procurement timetable. Thames Water is holding an industry day in August 2013 to share information about the Project – all applicants who want to attend the industry day must register their interest by emailing This e-mail address is being protected from spambots. You need JavaScript enabled to view it by no later than 13 August 2013. Attendance will be restricted to two people from each organisation. A recording of the event and materials presented will then be made available on the Project website from 6 September 2013 at http://www.thamestidewaytunnel.co.uk.

 Click here to download the tender documentation in full - available to registered readers who are logged in. Registration on Waterbriefing is free - sign up now.