Coppermills

The Coppermills programme forms a critical part of Thames Water’s long-term resilience strategy, involving the installation of a new 700 Mld High Lift Pumping Station and a 256 Mld Slow Sand Filter Recirculation system. The objective is to increase treatment capacity and resilience, improving clean water supply to approximately 400,000 customers across London.

Significant effort was invested during the pre-construction phase to de-risk the programme. This included intrusive surveys, groundwater monitoring, and progression of the planning application, alongside early delivery of enabling works. These works comprised major power upgrades, ICA system enhancements, service diversions within a highly congested site, and refurbishment or replacement of penstocks to facilitate critical outages aligned to an OFWAT-linked outage plan.

Given the scale, complexity, and risk profile of the programme, extensive time was dedicated to developing an appropriate procurement strategy. A collaborative approach with early contractor involvement was adopted, marking a strategic shift in Thames Water’s procurement model and setting a benchmark for future major projects. The project is currently at the final stages of tender following detailed negotiations to ensure value for money ahead of contract award.

Phoenix Consulting delivered:

• Commercial and contract management support across enabling and D&B works
• Development of procurement and contracting strategy
• Commercial input into self-delivered enabling works
• Tender evaluation and commercial negotiations
• Cost, risk, and value-for-money assessments
• Support through pre-construction and contract award

The pre-construction and enabling works phase has delivered measurable commercial benefits and significantly reduced downstream delivery risk. Self-delivery of selected works has resulted in savings of approximately £3.15m, driven by the avoidance of D&B contractor management fees, with further scope reductions anticipated post-contract award.

Through extensive commercial negotiations with the preferred bidder, the D&B contractor’s pricing has been reduced by approximately £75m following the first revision and a further £20m after the second. An additional £5m reduction is anticipated prior to contract award, subject to final review of insurance provisions already covered under Thames Water’s project insurance.

Collectively, the early commercial strategy, de-risking activities, and procurement approach have positioned the programme for successful delivery during the design and construction phases, with improved cost certainty, reduced risk exposure, and stronger value for money.