Thames Tideway Tunnel: procurement and programme management

The Thames Tideway Tunnel project is a deep tunnel system for combined sewer overflow (CSO) control in London, UK. It transfers flows to Beckton Sewage Treatment Works for treatment by way of the Lee Tunnel, which was officially opened in 2016. The needs and scope of the project are covered by Grant and Bailey (2025) and Fricker et al. (2025), respectively in this issue. The former provides an overview of the need for the project, technical solution, delivery model, financing and the non-statutory compensation scheme. The latter describes the scope distribution, design responsibilities, pre-contract design phases, some of the pre-contract system-wide design challenges and various contract design aspects.

Thames Water was the client for the whole project – from the feasibility phase, during the application for development consent through to the procurement of contractors and the project’s infrastructure provider. The Development Consent Order (DCO) was granted in September 2014 (HMG, 2014). The procurement culminated in three main works contracts and one system integrator contract being awarded on 1 September 2015, soon after Bazalgette Tunnel Limited (known as Tideway) became the infrastructure provider in August 2025 (Grant and Bailey, 2025).

The delivery of the project was split between Tideway and Thames Water, as shown in Figure 1 and described by Fricker et al. (2025). This paper concentrates on the procurement and the programme management of the portion of the project that Tideway was responsible for delivering. Thames Water was the client during the procurement phase and Tideway was the client during the delivery phase.

NEC3 Contracts were used for the three main works contracts (Option C) (NEC, 2013a), the system integrator contract (Option E) (NEC, 2013b) and the programme management contract (Professional Services) (NEC, 2013c). NEC3 is not an acronym, but the name of the conditions of the contracts used. Earlier editions were known as New Engineering Contracts. The following terms in this paper are capitalised as they are NEC3-defined terms: Employer, Project Manager, Works Information and Supervisor.

Thames Water’s vision, the project team organisation and operating model were structured to efficiently manage the project and to suit the needs and challenges in each phase. Tideway’s operating model followed the same high-level organisational principles, giving clarity to roles and responsibilities for those working on the project. In the delivery phase, these essentially fell into three broad areas.

• The client (Tideway) was ultimately accountable for the successful delivery of Tideway’s elements of the project. Tideway set the vision, strategy and objectives of the organisation and acted as the Employer under the NEC3 Contracts.

• The primary role of the programme manager (Jacobs) was to ensure integration, consistency and coordination of the works across the programme and provide assurance that Tideway’s objectives were delivered, including health, safety and wellbeing, environment, quality, cost, risk and schedule. The programme manager also acted as the Project Manager under the NEC3 Contracts.

• The primary role of the contracting organisations was to deliver the works according to the Works Information and to work collaboratively with the other contracting organisations, Tideway and the programme manager as an alliance.

Figure 2 provides a snapshot of Tideway’s operating model during the delivery phase of the project and Figure 3 shows the key roles of the leadership team.

A procurement strategy was developed that set out the approach to the procurement of all construction and associated works for the delivery of the project. The works were initially classified into three discrete categories.

• Category 1. Infrastructure provider works to be delivered by Tideway (known as Tideway’s works; see Figure 1). This covered all works associated with the interception of 18 CSOs and the tunnel system to transfer diverted flows for treatment (comprising 21 sites and 13 tunnels, with the main tunnel built in 4 individual drives), marine logistics (such as temporary cofferdams, temporary slipway, temporary jetty and, at Blackfriars Bridge Foreshore, the replacement of the Millenium Pier) and boat relocation works (including Battersea Barge, Tattershall Castle and a number of house boats).

• Category 2. Enabling works to be delivered by Thames Water prior to the award of the main works contracts. These included the power supply enhancement works required to drive the tunnel boring machines (TBMs), site investigations and surveys, utility strengthening/diversion works and the detailed design of boat relocation works. It was decided to deliver these works as early as possible to allow the main works contractors (MWCs) to start their works as soon as possible once the DCO was granted and contracts were awarded.

• Category 3. System works to be delivered by Thames Water (known as Thames Water’s works; see Figure 1): these included the control of two CSOs by locally modifying the sewer network and works at Beckton Sewage Treatment Works.

The procurement strategy for Tideway’s works had to establish the right environment for delivery and was prepared using learning from other major programmes delivered in the UK, such as the Olympic Delivery Authority (ODA) procurement, Crossrail procurement and Thames Water’s Lee Tunnel procurement (route shown in Figure 1). The procurement strategy took a similar approach to those of the ODA and Lee Tunnel, but it took a different approach to procuring marine logistics and transportation to Crossrail by putting that responsibility into the main works contracts as opposed to a client-led and managed delivery solution (Figure 4). Other learning that was adopted included the following.

• The most appropriate allocation of risk ownership, with risks allocated to the party best able to manage them to prevent them occurring in the first place, but also to manage mitigation if prevention was not possible. For example, the majority of the DCO obligations and local planning requirements were assigned to the contractors as they were best placed to manage and mitigate the associated risks with the relevant stakeholders; geotechnical risks were apportioned between the client and the contractors in a balanced way that protected the client to a level that was reasonable but also kept the contract tender values within an acceptable cost.

• Interfaces were a major risk, so they were simplified with interdependencies minimised, and the interface management and ownership clearly identified.

• The individual contracts were carefully designed to align objectives and to allow contractors to focus on performance (health, safety, wellbeing, schedule, cost) through incentivisation of outcome delivery. The alignment of project goals was a critical success factor.

Above all, the contract model, organisation and behaviours were designed to promote teamwork, collaboration and driving ‘best-for-project’ solutions.

For the three main works contracts and the system integrator contract, NEC3 Contracts were used. The MWCs were engaged through an Option C target price contract. For the system integrator contractor (SIC), an Option E cost-reimbursable form of contract was used, with an annually agreed cost plan. This allowed the flexibility required by the SIC to manage its interfaces with the MWCs.

The main works contracts were packaged geographically such that there would be a section of the main tunnel in each contract (west, central and east (as shown in Figure 1)), with tenderers able to bid for any number of packages, but only able to win one package.

These were design and construct contracts to encourage delivery of the optimum solution. Prior to tender, the project team developed a reference design with a set of requirements based on a performance specification and the requirements of the DCO. This formed the basis of the invitation to tender, together with a narrative setting out any other requirements and constraints that would form the basis of the NEC3 Contracts. This approach allowed sufficient design information to ensure quality, robust, competitive and deliverable tender bids to be received on an equal basis to secure value for money.

The procurement started with an industry day in late spring of 2013 and concluded, in parallel with the procurement of the new infrastructure provider, with the award of the final contracts on 1 September 2015. The infrastructure provider (Bazalgette Tunnel Ltd (Tideway)) was awarded their licence on 24 August 2015. There was significant interest in the three main works contract packages from national and international companies due to the size and complexity of the works, which led to multiple joint venture contracting partnerships submitting bids. There were four tenderers for each of the three main works contracts with each joint venture choosing to tender for either one, two or three packages.

The tender appraisal process for Tideway’s works was split between technical evaluation, commercial evaluation and behavioural assessment, with an evaluation weighting of 60%, 30% and 10%, respectively.

The technical evaluation focused on elements that were critical to the successful delivery of the contract. These included

• design management proposals

• delivery leadership and organisational structure, including the quality of management roles

• technical proposals and methodology for specific elements of the scheme

• legacy proposals

• health, safety, wellbeing and security initiatives

• quality, environmental and delivery execution plans

• risk management proposals

• interface and stakeholder management proposals

• other specific proposals for delivering the contract.

The commercial evaluation examined the tendered ‘total of the prices’, inclusions for risk and fee, as well as any adjustments (e.g. contractual qualifications). The commercial scoring model was comprehensively tested through a sensitivity analysis to ensure it was fit for purpose and encouraged the desired open and collaborative behaviours from the tenderers in line with programme objectives. The evaluation assessed the content of the commercial submissions to ensure that

• pricing was complete, comprehensive and correct with no omissions or errors

• pricing was robust, realistic and deliverable

• tenderers had based their bid on the same assumptions so that bids could be scored on an equal ‘like for like’ basis

• the commercial and technical submissions aligned with each other

• submissions did not contain any unacceptable qualifications, changes or options

• areas for potential negotiation were identified

• the bids were not abnormally low.

The final tender evaluation category was the behavioural assessment. Behavioural assessment (‘soft skills’) workshops were used as part of the evaluation process to assess the tenderers’ team behaviours in practice. These included team tasks designed to assess the tenderers’ ability to interact within their own team and with the project team. Areas assessed included

• leadership – demonstration of effective leadership behaviours and know-how

• change management – the demonstration, understanding and application of effective change management and problem solving strategies and practice

• working collaboratively with stakeholders – the demonstration of a willingness and ability to adopt a collaborative approach to working with all stakeholders

• innovation and continuous improvement – the application of behaviours that promote innovative thinking and continuous improvement

• culture fit and shared values – acknowledgement of the importance of organisational values and culture and developing plans to ensure fit

• health and safety – the demonstration of commitment to achieving and maintaining excellence in health and safety

• working together (trust) – the demonstration of working together to promote trust between people.

The behavioural assessments were conducted by a team that was completely separate to the technical and commercial assessments in order to avoid any bias. Since it was expected that the tender teams would be coached, the scenarios were devised to take this into account with the anticipation that any pretence could not be sustained over the whole duration.

Following completion of the evaluation, a process of moderation was undertaken to ensure the agreed provisional scoring was appropriate before an evaluation assurance exercise was completed to finalise the contract award recommendations. Through this process, the system integrator contract was awarded to Amey. The three main works contracts were awarded as follows.

• West section: joint venture of Bam Nuttall, Morgan Sindall and Balfour Beatty (BMB).

• Central section: joint venture of Ferrovial Construction and Laing O’Rourke (Flo).

• East section: joint venture of Costain, Vinci Construction Grands Projets and Bachy Soletanche (CVB).

More details are provided in Figure 5.

Over the NEC3 contractual framework, a bespoke alliance agreement was set up with the SIC and the three MWCs, the client (Tideway) and Thames Water, who will ultimately operate the system and own the permanent works other than the tunnels and shafts. Through this agreement, shared incentives, aligned to programme cost and schedule, were used to foster a best-for-project approach when faced with interface and programme-wide decisions. To oversee and implement the agreement, two monthly forums were established: the Alliance Board and the Alliance Management Team.

The Alliance Board was a forum of senior leaders from the alliance organisations to raise and resolve issues arising from, or which may arise from, the interfaces between the works being delivered by their respective organisations. The Alliance Management Team was a forum for strategic discussion regarding the day-to-day execution of the project and to resolve issues arising during the design, construction, commissioning and acceptance of the Thames Tideway Tunnel. It also reviewed and proposed amendments to the integrated project master programme such that best-for-project decisions could be made.

The alliance was very effective in driving transformational health, safety and wellbeing excellence, standardising designs (especially for mechanical and electrical equipment) and sharing best practice and lessons learned.

This commercial and contractual approach enabled

• early contractor engagement to drive design and programme efficiencies

• close collaboration between all to ensure best-for-project outcomes to issues as they arose (e.g. when the alliance agreed which contract had priority over others during periods when the limit on barge movements was reached)

• end user/asset owner involvement from a very early stage to ensure smooth progress and handover.

However, through unforeseen circumstances, such as the Covid pandemic, the alliance incentives became unachievable and, consequently, supplementary agreements were implemented to continue to incentivise each of the contractors to achieve key programme objectives (milestones, quality certification and documentation, readiness for commissioning).

As a result, the alliance continued to be a key management tool for delivery, coordination and oversight. The alliance met more regularly as the construction neared completion when closer coordination was required for shared resources and the self-contained construction sites became part of a wider operational system, with the change in risks this brought.

To support delivery of the project, Jacobs was appointed as programme manager through a project management contract, based on NEC3 (NEC, 2013c), to provide programme management, NEC project management and assurance services. Various task orders under the contract were instructed to support the management and assurance of the four contracts and their delivery. To deliver these services, an organisation was formed of the following.

• Delivery teams, responsible for the delivery of the main works contracts and the system integrator contract. Each area delivery manager fulfilled the role of the independent Project Manager under the NEC3 Contracts.

• A programme management team, responsible for the system-wide assurance of works in accordance with the specification, ensuring integration, coordination and consistency across the contracts and assuring the delivery of health, safety, wellbeing, consents, quality and environmental objectives. This team was also responsible for the integrated reporting of schedule, cost, quality and risk.

One particular area of success was the constructive tension created by the independence and separation between the programme manager’s area delivery teams (led by the NEC Project Managers) and the design and quality assurance functions, ensuring compliance with Tideway’s design requirements and quality standards. This was achieved by having dual reporting lines for the NEC Supervisors and the Design Authority to the Chief Technical Officer and to the Programme Director (see Figure 3).

The programme and project management teams comprised a mix of permanent Jacobs and Tideway staff, but also subcontract and framework resources to undertake specific roles. These resource numbers and competencies evolved continuously to meet the demands of the project. One of the key success factors was the continuity of the team through the lifecycle of the project, allowing continuity of knowledge from project development and the DCO process into delivery. It was not unusual to find team members within the delivery supply chain with more than ten years’ experience on the project. Along with continuity, the team was able to adapt to the changing needs of the project and the client.

The programme manager (Jacobs) implemented integrated project controls, with a deep focus on risk management playing a crucial role in the delivery framework. Risk-based reporting and ranging were placed at the heart of project controls, recognising that complex major programmes are inherently risky. Annual risk-based baselines were established, and quarterly risk-based and monthly target updates were undertaken, all supported by early-sight meetings between the programme management team and the client to ensure key assumptions, exclusions and constraints were discussed and agreed. These annual risk-based baselines underpinned the client’s yearly forecasts and targets, providing confidence to the Tideway Board and the stakeholders. This approach ensured a no-surprise culture, allowing smooth project execution and stakeholder satisfaction.

To supplement this approach, the programme manager was incentivised through flexible key performance indicators (KPIs) to enable a strategic focus, initially set as part of the annual business planning process but reviewed quarterly to ensure they remained relevant to the demands of the project. These KPIs were predominantly focused on the timely provision of key reporting data, the delivery of programme-wide assurance and the retention of key staff, but could also include more subjective matters to suit the needs of the client.

The team reporting on schedule, cost and quality to the programme manager was the PMO, while that reporting to the client was the PAO. The structure of the PMO, and its approach to reporting, evolved through the lifecycle of the project. Initially, the use of the programme manager as a trusted partner allowed for an internal independent view of the schedule and cost of the integrated programme based on the programme manager’s view of the contractual position of Tideway’s works. The client’s PAO was then able to give a strategic view of the PMO’s view of the data for onward reporting. This approach allowed for early visibility and constructive challenge of the potential impact of project issues and how they would be reported to wider stakeholders.

This approach resulted in some key programme/project controls achievements.

• Strategic target baseline. An early challenge to the four contractors to reduce the programme by 2 years (17 months was achieved) enabled the project to start on site earlier, find and resolve obstructions earlier and therefore de-risk the schedule.

• Resolution of the tunnel/contract interfaces between the west–central and east–central areas (see Lewis et al. (2025) on this issue). Using best-for-project scenario modelling, significant risk, cost and programme savings were achieved.

• Risk-based reporting and Covid assessments. This led to stakeholder confidence and client engagement through early sight of the schedule and associated stable reporting. This allowed for transparent top-down challenges on a ‘whole-team’ bottom-up assessment.

• Integrated programme controls. There was a robust programme breakdown structure, aligning across schedule, cost, risk and change. This hierarchy of schedule, cost and risk allowed integration/audit trail from the contractors to the ultimate reported position.

The key deliverable for the PMO was the integrated project master programme – a consolidated view of the four contracts to give a programme view of progress and key interface milestones for Thames Water. This was used to report the programme managers’ mitigated position to moderate the MWCs’ commercial view of the schedule, to provide a stable reported position. Although the schedule and cost positions were updated on a monthly basis by the PMO, a risk-based position was only reported to the Tideway Board and external stakeholders on a quarterly basis by the PAO to allow a smoothing of the month-on-month changes and avoid the fluctuations of schedule and cost data that are inevitable on a major programme.

Figure 6 shows an example of the main tunnel construction progress report, using a time/chainage format, that formed part of the PMO’s quarterly report.

As below-ground works neared completion and the major construction interfaces had been resolved, the programme manager’s PMO and the client’s PAO combined to form an integrated PMO (IPMO) to align reported data and messaging, with resulting reductions in the amount of reporting and associated resources. This combined approach was based on a number of different inputs and outputs

• Reduced programme manager delivery reports, separate from Tideway’s report, maintaining an independent position

• Integrated schedule and risk continued to be produced by the area delivery teams

• Cost reporting produced by the IPMO based on inputs from the area delivery teams and integrated schedule.

The programme manager’s assurance strategy throughout the project was based on the following eight principles.

• A clear hierarchy of documentation and cascade of requirements.

• Progressive submission, review and feedback of deliverables throughout the project.

• Identification of priority areas of focus, which included health, safety, wellbeing, environment, security, marine, consents and quality.

• Monitoring and completion of assurance activities in accordance with the three lines of defence model (further described in Section 3.2.2) and an assurance framework that was developed by the programme manager and agreed in advance with the client team.

• Evaluating the outcome of assurance activities to establish emerging trends.

• Identification of actions to prevent and correct emerging trends and ensure lessons were learned across the whole programme.

• Effective and transparent reporting to the client organisation.

• Harnessing learning from across the industry and disseminating that learning across the programme.

Progressive assurance was a key part of the programme manager’s assurance principles. This began with a clear hierarchy of documentation to ensure that the aims, objectives and constraints of the project flowed into, and became embedded within, the contract requirements. The DCO, granted in 2014, with its supporting documents such as the River Transport Strategy, identified various constraints and conditions for works. An interface agreement between Thames Water and Tideway to facilitate the delivery of works also contained constraints and conditions. The Works Information in the three main works contracts and the system integrator contract was written to incorporate the requirements of the above documents and required the design to be developed accordingly. This cascade of requirements is illustrated on the left-hand side of Figure 7.

The Works Information required the development and submission of various management plans that explained how works would be delivered in compliance with the contract requirements, and consequently the Interface Agreement and the DCO. These management plans were reviewed by the area delivery teams and implemented by the four contractors. One such plan was the design management plan, which demonstrated how each contractor would develop their detailed designs within the structure of a gate review process (see Fricker et al. (2025) in this issue).

A ‘three lines of defence’ model was adopted to ensure that management systems and designs, developed and accepted to be compliant with the Works Information, and consequently the requirements and principles of the Interface Agreement and DCO, were implemented as planned.

• The first line of defence was through the procurement of competent contractors to deliver all scopes of work. All the MWCs and the SIC, as well as any supporting contractors managed directly by Tideway (such as archaeology), were required to demonstrate compliance with the requirements of ISO 9001:2015 (ISO, 2015). Contractors were responsible for day-to-day oversight of project works and encouraged to report issues relating to health, safety, wellbeing, environment, security and quality (including non-compliance) in a no-blame culture. This facilitated open dialogue about the root cause of issues and the ability to identify and address trends as they emerged. Within six months of the contract start date, the contractors were also required to develop and implement an ISO 9001:2015-compliant quality management system with self-certification of contractual requirements. This ensured clear responsibility and ownership of the requirements. Each of the three MWCs used one of their parent company’s quality management systems and compliance was confirmed prior to commencement of construction.

• The second line of defence was provided by subject matter experts within the programme management team, the Design Authority and the NEC3-appointed Supervisor. The programme management team developed an assurance strategy that included site inspections, surveillance activities and shadowing of contractor-led audits by experts within each of the priority areas of focus stated above. Following discussion with site teams, positive observations and non-compliances were recorded by the programme management team on a shared reporting platform alongside the contractors’ own findings to ensure clear and visible responsibility and tracking of actions, and to help facilitate the identification and sharing of trends and best practice across the programme. The second line of defence also included the establishment of the Design Authority team, whose role was identified during development of the Interface Agreement to provide assurance for the detailed design undertaken by the contractors, and the use of independent Supervisors under the NEC3 Contracts who were required to impartially test and inspect on behalf of the client that the works provided by the contractors were compliant with the requirements of the contract. The Design Authority and Supervisors provided regular reports to the senior leadership of both the programme manager and client teams, such as through the regular technical assurance group, which was chaired by Tideway’s Chief Technical Officer and attended by the Programme Director.

• The third line of defence was provided by the client team’s internal audit function and external entities, which were contracted to conduct targeted assessments and audits proportionate to risk. This function was mandated by Tideway’s Board and Audit Committee, and focused on assuring that internal control processes were robust and effective in mitigating key risks.

Throughout the project, reports from all three lines of defence were collated and presented to Tideway’s Compliance and Review Group, a group led by the Chief Executive Officer and focused on reviewing the appropriateness and compliance of the company’s activities, both as the client and through the programme manager and the contractors.

The contract defined various completion milestones, culminating in completion of the whole of the works, which required the three MWCs and SIC to self-certify that all Works Information requirements applicable to a particular milestone had been achieved as works progressed. The certificates used by the contractors to demonstrate the achievement of each milestone were based on a contractor-led structure of sub-construction, construction and completion certificates. While this contractor-led approach ensured that responsibility clearly rested with each contractor, there were examples of certificate groupings that were inconsistent between the three MWCs. Certificate groupings could have benefitted from an overarching framework led by the Project Manager to ensure a level of consistency by, for example, grouping construction certificates by agreed work types, and then by site.

The completion milestones were closely linked to the final design gate (gate 6), which required the submission of as-constructed records and other documentation needed to facilitate commissioning and takeover of the works. Information on the design gates used on this project is provided by Fricker et al. (2025). The three lines of defence model continued to review these submissions, assure the self-certification of works and consequently assure the project’s compliance with the Works Information, the Interface Agreement and the DCO.

Interfaces across the project were reviewed early in the application for development consent, and there was a focus to reduce the number of interface points as much as possible given the inherent risk of managing and controlling interfaces on such a large-scale programme. The physical interfaces were limited to the following.

• The main tunnel interface points between the three main works contracts (west–central (Figure 8) and central–east) and between the east section and the Lee Tunnel (which was delivered by Thames Water).

• Connection of the CSO interception structures with the existing Thames Water sewerage network.

• The system integrator works, interfaced with each of the three main works contracts, as well as Thames Water’s supervisory control and data acquisition system.

These interfaces were managed through regular coordination meetings. The programme management team played a key role in managing the interfaces by holding regular readiness reviews to ensure risks were identified and mitigation plans put in place before proceeding with the next stage of work. Details of the interfaces were captured in interface control documents, which were used to document control measures and provide assurance that risks were being appropriately managed. The programme management team also played a role in resolving clashes at the interface points by assessing various options and recommending best-for-project approaches to the client for approval and implementation through the contracts.

Stakeholder management involved identifying, engaging and managing the various groups and individuals having an interest or stake in the project’s success. Tideway’s engagement strategy aimed to build trust, mitigate risks and foster collaboration. It involved public consultations, meetings and transparent reporting on the project’s progress. Particular attention was given to minimising disruptions to communities and the environment while ensuring that the project met its schedule and objectives.

During the application for development consent phase, stakeholder engagement played a critical role in securing regulatory approval and addressing the concerns of a wide range of parties impacted by the project. This involved extensive consultation with key stakeholders, including local authorities, environmental groups, residents and businesses.

Tideway’s strategy continued throughout the delivery phase and much of the project’s success can be attributed to the proactive and inclusive approach to stakeholder engagement, which helped address potential conflicts early and ensured increasingly broad support for the project as it progressed through to completion.

Key learnings and best practice included the following.

• Setting up an early presence on site with establishment of information centres at key sites that were staffed by local members of the project team. The information centres were open regularly during the week and made available to members of the public who had questions or concerns about the project.

• Community liaison working groups (CLWGs) were established early in the project. In these meetings, the project team would provide regular face-to-face updates to local communities of upcoming works and measures taken to reduce impacts on the surrounding community. The CLWGs were chaired by an independent party to provide confidence to the local community that the meetings were impartial.

• Weekly update emails were sent to local community groups and residents, providing information on upcoming works to provide transparency and avoid surprises.

• Regular engagement with Tideway’s strategic relevant authorities, including the Environment Agency, Transport for London, the Port of London Authority and local authorities, ensured Tideway complied with its statutory requirements but also helped to achieve a smoother path through required approvals and consents.

• The Thames Tideway Tunnel forum was a regular forum chaired by an independent party that was established during delivery to ensure effective communication and collaboration between Tideway senior management and key stakeholders. It played a key role in maintaining positive relationships with due regard for the concerns and interests of those affected.

• Key stakeholders and local authorities were funded by Tideway and co-located in many instances. Additionally, stakeholders and consents resources were embedded within the site teams, which proved effective in gaining timely approvals and resolution of concerns when raised.

The Thames Tideway Tunnel project teams developed new thinking around procurement and programme management for major projects, while adopting best practice and learnings from previous major projects, to ensure successful project delivery. This success was underpinned by several key factors, including an increased emphasis on collaboration and alignment of vision and values, a simplification and clear ownership of interfaces, a deep focus on risk management and a continuity of resources.

Learning from predecessor major programmes, the procurement and programme management structure and culture was established early on – shown through its contract model, programme management organisation, collaborative internal culture and proactive external stakeholder engagement – to ensure the best possible chance of success.

The increased emphasis on best-for-project collaboration, in both contractual frameworks and in delivery through the Tideway alliance setup, was not a completely unique approach, but it delivered major benefits in terms of effectively managing risks and delivering consistently high standards.

A fresh approach to these best practice structures was introduced in key areas, for example the dual reporting lines for the NEC Supervisor and Design Authority to the Chief Technical Officer as well as the Programme Director.

This was all overlaid by the alignment of project goals, initially set by Thames Water to inform the selection of the contracting and infrastructure provider organisations and then reinforced by Tideway to set roles and responsibilities of the client and programme management team. It was supported by a continuity of key resources within the project and programme management teams through the project lifecycle, allowing a ‘golden thread’ of knowledge through project development and the DCO process into delivery.

A special mention is given to Deniz Lowe, whose contributions as a senior project manager were vital over many years. He sadly died before seeing the project completed.