A “particularly strong” performance in the UK water sector has boosted RSK’s construction revenue, according to the environmental, engineering and technical services conglomerate’s latest accounts.
It said “continued investment” in water frameworks had delivered substantial work for its UK construction businesses, with more expected to follow.
RSK’s construction activities delivered turnover of £639.2m in the year to 6 April 2025, up from £511.9m the year before.
The accounts did not state how much of that work was done in the UK, and nor did they give a pre-tax profit figure for RSK’s construction-specific work.
But group managing director Alasdair Ryder said its UK performance was driven “primarily [by] the design and delivery of large-scale assets in the water sector, including water and wastewater treatment works and reservoirs”.
He added: “Performance in the UK water sector, a core strength in RSK, was particularly strong with the group benefiting from continued investment through [Asset Management Plan] AMP7.”
The AMP7 regulated investment cycle began in 2020 and ended in March this year.
The future outlook for UK water also looked positive, Ryder said, “as record investment levels have been announced for AMP8 [until 2030]”.
RSK construction subsidiaries such as MWH Treatment and WGM Engineering had already secured spots on AMP8 frameworks, he added.
RSK Group acquired MWH Treatment in 2021. In its most recent results, for the year to 31 March 2024, MWH Treatment made a revenue of £346.2m and a pre-tax profit of £7.5m.
Despite the impressive performance in the water sector, Ryder said that RSK had been hit by “continued pressure on project costs” within the UK and elsewhere.
“To support improvement in this year, the group has doubled down on efforts to maximise the use of internal subcontractors, where practical, and has also launched a pricing programme which, in part, considers pass through project costs,” he added.
The group’s principal projects in the UK include a MWH Treatment project to develop the Witches Oak Water Treatment Works in Derbyshire (pictured), and a carbon capture and storage project in Liverpool Bay with RSK Environment.
Work outside the construction sector makes up the majority of RSK’s profile, as the group posted revenue of £2.2bn in the year, up from £1.9bn in 2023/24. The vast majority of its work – £1.8bn worth – was in the UK.
But it made a pre-tax loss of £124.5m, down from £132m the year prior. Cash was up to £176.8m from £132.2m, and the group paid out dividends of £5m.
The group owed £72.1m in bank loans and borrowings within 12 months, up from £60.6m the year before. But its long-term repayable bank debt was reduced from £1.13bn to £838.6m.
RSK employed 14,953 staff worldwide and its annual wage bill rose from £641.3m to £750.9m.
Since the year-end, RSK made a single construction acquisition in the UK, when it bought Glasgow-based AJ Engineering & Construction Services for £6.1m in June.
The firm, which delivers steel fabrication and cladding services, made a pre-tax profit of £1.9m from turnover of £20.5m in the year to 30 March 2024.
“Acquisitions remain an important element of our growth strategy, expanding the breadth and geographical coverage of our services to meet growing client demand for solutions that will drive sustainable growth and business resilience,” Ryder said.