Thames Tideway Tunnel

The Thames Tideway Tunnel set out to tackle one of London’s oldest challenges: keeping the River Thames clean as the city grows.

It brought together deep tunnelling, major upgrades and construction across busy urban sites, all within a single, complex programme.

Building the programme around clarity and control

This was one of the largest infrastructure projects London has seen in generations. Getting the structure right from the start was critical.

We provided project and programme support across the lifecycle of the scheme, helping to set up the Programme Management Office and establish practical ways to manage risk and schedules. We also worked closely with commercial, legal and technical teams, reviewing contracts, shaping schedule clauses and supporting the Development Consent Order process.

A key part of our role was developing an integrated programme schedule. This gave teams a clear view of how everything linked together, from tunnelling works through to treatment plant upgrades.

Managing complexity across a busy city

The programme spanned 24 sites, many along active stretches of the Thames, each with its own constraints.

We coordinated work across contractors, third-party infrastructure teams and local stakeholders. By aligning schedules and testing interfaces early, we resolved clashes before they reached site.

Our team collaborated with contractors to review and refine their programmes, making sure plans reflected real construction conditions and approvals. When COVID-19 disrupted delivery, we assessed the impact and worked with teams to plan a safe return to site.

Supporting better decisions throughout

Our long-term involvement brought continuity to a complex and evolving scheme. We supported strategic planning throughout, giving programme leaders a clear view of progress, risks and opportunities. By tracking interdependencies across the works, we kept sight of how each part affected the whole.

Regular updates to senior leaders, regulators and ratings agencies meant decisions could be made with clarity and confidence. We also shared lessons from other major infrastructure projects, strengthening the programme’s ability to respond as challenges emerged.

A cleaner river for the future

The Thames Tideway Tunnel will transform how London manages its wastewater, reducing pollution and improving the health of the river.

It’s a major step forward for the city’s infrastructure, designed to support future growth.
Behind it sits a programme built on clear planning and a strong understanding of how every part fits together.