Scotland’s water regulator has reported growing delays in Scottish Water’s infrastructure commitments, even though the publicly owned utility continues to deliver high customer satisfaction and spending remains broadly in line with its financial plan.
The Water Industry Commission for Scotland (WICS) published its assessment of Scottish Water’s 2025–26 performance on Wednesday, 4 November. It found that the number of investment output areas behind schedule had increased from 22 to 32 during the year, while risks had grown around environmental and climate-related commitments.
Across the first five years of the current six-year regulatory period, Scottish Water invested £3.636 billion in maintaining and improving water and wastewater services. That was only £10 million below the total assumed when customer charges for the period were set. The regulator’s concern is therefore not simply the total amount spent: it is whether that expenditure is producing the planned improvements on time.
WICS found that routine service performance remained among the strongest recorded in the current regulatory period and that customer satisfaction was high. Nevertheless, leakage performance narrowly missed the target range, despite an increase in the number of leaks repaired, and compliance at wastewater treatment works declined compared with the previous year.
The assessment also warned that Scottish Water remains behind its interim target for reducing operational carbon emissions. There is a risk, according to the regulator, that the utility will not meet its commitments under its Improving Urban Waters Routemap, which addresses the performance and environmental effects of wastewater systems.
These findings matter because Scotland’s water infrastructure consists of long-lived assets whose condition is not always apparent to households receiving a normal service. Water-treatment facilities, pumping stations, underground pipes and wastewater works require maintenance and renewal long before failures become visible. A programme can remain close to its spending budget while individual upgrades or environmental improvements fall behind their intended delivery dates.
Scottish Water disputed any suggestion that the picture was predominantly one of underperformance. In its response to the new assessment, chief executive Alex Plant emphasised strong customer service, high drinking-water quality and continuing investment. He said some longer-term outputs were behind schedule while others were ahead, reflecting changes in priorities during delivery. The company expressed confidence that it would complete its commitments.
The utility’s own annual report, published in August, described 2025–26 as its second-best operational year and reported £1.13 billion of investment in new works, repairs and upgrades. It also reported drinking-water quality compliance of 99.92 per cent and two serious pollution incidents, its lowest annual figure. Those figures provide important context, but they do not overturn the regulator’s separate findings about missed milestones and environmental risks.
The distinction between service quality today and investment delivery for the future is central to the regulator’s assessment. Customers can experience reliable drinking water and sewage services while parts of the capital programme intended to sustain or improve those services still require attention. The pressure is intensified by ageing assets, extreme weather and changing demand across Scotland.
WICS says it will pay particular attention during 2026–27 to the areas that are behind plan and to the steps Scottish Water takes to recover delivery. The regulator is also due to publish its Final Determination for 2027–33 on 12 November, establishing the framework for future charges, investment expectations and performance obligations. That decision will be an important next test of how Scotland intends to fund and manage its water network in the coming years.
Sources
Scottish Water’s 2025–26 Performance, Water Industry Commission for Scotland, 4 November 2026.
https://www.wics.scot/latest/scottish-waters-2025-26-performance
Scottish Water Response to WICS Performance Report, Scottish Water, 4 November 2026.
Scottish Water Delivers Second Best Year Despite Extreme Weather, Scottish Water, 13 August 2026.
https://www.scottishwater.co.uk/about-us/news-and-views/2026/08/120826-scottish-water-annual-report
