Ofwat's £104bn water investment: what civil engineering contractors need to know about AMP8

Ofwat’s December 2024 PR24 final determinations, summarised in the CMA redetermination documents, approved £104 billion of investment in water and wastewater infrastructure for England and Wales between April 2025 and March 2030. That is Asset Management Period 8 (AMP8), close to double the investment of the previous five-year period. Here is what is actually being built, who controls the money, and what a civils contractor needs to do to get on it.

What the £104bn covers

The total expenditure allowance breaks into two parts: £60 billion of base expenditure (the routine maintenance and renewal work that keeps systems running) and £44 billion of enhancement expenditure (new or improved capacity to meet performance commitments). That split matters because the enhancement spend is where the largest civil engineering scopes sit.

Three themes dominate.

Storm overflow reduction. Almost £12 billion is allocated to cutting combined sewer overflow spills by 45% from 2021 levels by 2030. CSO remediation is civil engineering-intensive: offline storage tanks, real-time control chambers, pumping stations, upsized sewer connections, and reinstatement. Individual schemes can run from a few hundred thousand pounds for a small overflow improvement to tens of millions for a major attenuation installation in a dense urban catchment.

Pipe replacement and leakage. Ofwat is requiring a 17% reduction in leakage across the sector, with the rate of mains replacement tripled from the previous period. More than £700m is earmarked for leakage reduction directly, and £456m for replacement mains, but the physical programme of trenching, bedding, connection, and reinstatement touches almost every distribution network in England and Wales.

Strategic water resources. Around £2 billion is directed at starting the first phases of long-term strategic water resource schemes, part of a collaborative planning programme that Ofwat and Defra estimate at roughly £50 billion of investment over the coming decades. Strategic transfer pipelines, new reservoirs (the first in southern England in 30 years), and inter-regional connections all have significant civil engineering packages attached.

The CMA process is settled

Five companies (Anglian, Northumbrian, South East, Southern, and Wessex) challenged their PR24 determinations by referring to the Competition and Markets Authority. The CMA published its final decisions on 26 March 2026, granting the five companies £463 million in additional revenue (17% of what they had asked for). The allowed investment programme remained largely intact.

Thames Water took a separate path, requesting a CMA reference and then asking Ofwat to defer the formal referral while its financial restructuring continued. Thames Water is still the largest single investment programme in the sector; its capital delivery is proceeding under closer management and the CMA’s March 2026 determinations do not apply to it.

Despite the Thames exception, procurement has moved forward across AMP8.

How the money actually reaches contractors

Water companies do not buy civil engineering services through open tender. They operate through long-term capital delivery alliances and major projects frameworks with a small number of appointed tier 1 contractors, who then build regional and specialist supply chains beneath them.

The major framework appointments for AMP8 have either been made or are close to conclusion:

Thames Water launched a £4 billion Major Projects Framework spanning AMP8 and into AMP9, covering treatment plant upgrades, new pipelines, pumping stations, and associated civil engineering. The procurement opened in September 2025, with places due to be awarded in March 2026 and the appointment planned to run for up to nine years.

Anglian Water’s £1.5 billion Major Projects Framework sits within a total AMP8 programme Anglian describes as £11 billion. Since April 2025 it has already started more than 850 capital schemes, completed 127 kilometres of its Strategic Pipeline southern section, and connected more than 60% of customers to smart meters. The major projects procurement closed in early 2026 with appointments expected in summer 2026.

Wessex Water announced £3.7 billion of AMP8 delivery partners. Southern Water awarded its capital delivery frameworks in 2024, ahead of AMP8 starting.

The window for many prime framework positions has largely closed or moved into final procurement. The opportunity for civils contractors now is to get onto the supply chains of the appointed tier 1 firms before their regional subcontract books fill. That means completing registration and supply chain outreach before a specific opportunity appears.

What the civil engineering scope looks like on site

A contractor experienced in commercial groundworks will find some AMP8 scopes immediately familiar and others genuinely different.

Storm overflow schemes are often in urban areas, working within and around live sewer networks. Access is constrained, working hours are restricted, noise and reinstatement standards are more tightly policed than on greenfield sites, and coordination with drainage teams and network control rooms is continuous. Storage tanks can be large, requiring deep excavations, engineered temporary works, and accurate concrete placement in confined conditions.

Pumping station upgrades involve new wet wells, valve chambers, rising main connections, and surface reinstatement to adoptable standards. The footprint is contained but the depth and proximity to live systems make each scheme more demanding than its size suggests.

Mains replacement in the highway involves NRSWA street works permits, traffic management, reinstatement to Specification for the Reinstatement of Openings in Highways (SROH) standards, and coordination with local highway authorities. A contractor that is strong on industrial estate groundworks but has no experience of utility highway works will find the governance unfamiliar.

Strategic pipeline work involves large-diameter HDPE or ductile iron mains laid over long distances, often across agricultural land, with watercourse crossings, horizontal directional drilling or thrust boring at roads and railways, and reinstatement to agricultural standards across multiple landowner parcels. The civil scope on a single strategic pipeline can exceed £20 million.

Treatment works upgrades vary by site age and complexity. The civil scopes range from relatively contained package plant installations to multi-year programmes involving new primary settlement tanks, filter beds, sludge handling infrastructure, and extensive internal drainage. These are typically let as separate civil subcontracts within a larger engineering and process contract.

What water sector access requires

Water sector site access is more nuanced than a single card. SHEA Water is the sector’s one-day safety, health and environmental awareness scheme for operational sites, and it carries CSCS Alliance status. Clean water sites and clean water network work normally require National Water Hygiene EUSR registration as well; EUSR states that all UK water companies require it for clean water sites and restricted operations.

The EUSR card system also covers more specific competencies: confined space entry, pipeline operations, and safe digging, all of which apply directly to the civils scopes in AMP8. A civils team that leaves SHEA Water, National Water Hygiene, NRSWA, confined-space, and role-specific registrations until the first enquiry will be behind the programme. Getting that in order takes time and should happen well ahead of the first tender conversation.

Pre-qualification for supply chain positions typically requires Constructionline or CHAS membership, SSIP alignment, ISO 9001 and ISO 14001, appropriate insurance limits (water company sites often require higher limits than standard commercial work), modern slavery compliance, and a waste carrier licence. Most delivery partners run their own supply chain audits before awarding regional or specialist subcontracts.

The final requirement is experience. Delivery partners for major water programmes want to see evidence of utility or water sector work in references, not just comparable civil engineering. A strong record on logistics parks or industrial units is not sufficient on its own. If the Rospower team’s civil references are currently outside the utility sector, the practical route is to target a smaller scheme or local authority drainage work that bridges the gap, then build the water sector reference.

Where the peak work falls

AMP8 started in April 2025. Year one was dominated by scheme design, contractor onboarding, enabling works, and smaller replacement programmes. The larger capital schemes, including major overflow storage installations, strategic pipeline routes, and treatment works upgrades, typically mobilise in years two and three. That puts the peak of AMP8 construction activity in the 2026-2028 window.

For civils contractors without existing water sector supply chain positions, the current period is the right moment to build them. Tier 1 delivery partners are extending their regional subcontract books now. A contractor that completes its SHEA Water, National Water Hygiene or other EUSR registrations, supplier pre-qualification, and supply chain outreach before the larger packages mobilise will be meaningfully ahead of one that waits for the tender notice.

The £104bn figure is real investment, not pipeline aspiration. The work started in April 2025 and will continue through 2030. The scopes are civil engineering-heavy, many frameworks are decided or in final procurement, and the access route is known. What it requires is the same preparation that any utility sector entry requires: the right cards, the right compliance, and an early conversation with the right delivery partners.

Connor Lyons is commercial director at Rospower Projects, MRICS. We deliver civil engineering, groundworks, drainage, utilities, and project management for infrastructure, utility, and public-sector clients across the UK. Contact us to discuss a planned infrastructure or utility package.

Sources and further reading

• PR24 final determinations summary (CMA, March 2026)
• Water PR24 price redeterminations (CMA, GOV.UK)
• PR24 final determinations explained (CIWEM)
• Thames Water opens race for £4bn AMP8/9 framework (Construction Enquirer, September 2025)
• Anglian Water starts hunt for suppliers on £1.5bn Major Projects Framework (New Civil Engineer, February 2026)
• SHEA Water (EUSR)
• National Water Hygiene (EUSR)
• How to reinstate a road after doing street works (GOV.UK)