Scottish Water has recorded its second best operational year since the publicly owned utility was created in 2002 despite some of Scotland’s most challenging weather conditions in decades.
Its 2025 to 2026 annual report shows a record £1.13 billion was invested in water and wastewater infrastructure as services faced Scotland’s driest start to a year since 1964 followed by periods of intense rainfall and flooding.
Customer satisfaction reached its highest level on record, while Scottish Water recorded the highest trust score of any UK water and wastewater company.
Drinking water quality compliance remained at 99.92 per cent.
Serious environmental pollution incidents also fell to their lowest recorded level, with two during the year, although Scottish Water’s target remains zero.
The utility achieved 98 per cent of its investment milestones, with major projects completed around two months ahead of schedule on average.
Among the largest was the completion of 100 miles of pipeline connecting the Greater Glasgow and Ayrshire water supply zones.
The project is the biggest capital development in Scottish Water’s history and is designed to strengthen the resilience of water supplies.
More than 1,100 smart water monitors were also installed as part of a pilot programme aimed at tackling leakage, improving awareness and helping the network respond to problems more quickly.
Scottish Water completed 50 energy projects during the year, delivering 4.51GWh of energy efficiency improvements and saving 10,300 tonnes of carbon dioxide equivalent.
The annual carbon benefit delivered since 2021 has now reached around 49,000 tonnes.
Chief Executive Alex Plant said:
“This was a year that really tested us.
“We experienced Scotland’s driest start to a year since 1964, followed by periods of intense rainfall and flooding.
“However, every single day our teams and delivery partners kept water flowing, treated wastewater, protected the environment and supported communities across the country.
“I’m incredibly proud that we delivered another very strong performance while achieving record customer satisfaction and reducing serious environmental pollution incidents to their lowest level ever.
“We’re also determined to be open about where we need to improve.
“Leakage remains one of our biggest challenges and, while drinking water quality remains very high at 99.92% compliance, warmer, drier weather, ageing infrastructure and changing raw water quality are increasing the pressure on our services.
“That is why we must keep investing, innovating and improving.”
Those pressures are shaping plans for considerably greater investment in the years ahead.
Scottish Water is developing a proposed £13.4 billion programme covering 2027 to 2033 following input from more than 25,000 customers and stakeholders.
The programme would renew ageing infrastructure, improve water quality, reduce sewer flooding and further protect Scotland’s rivers and coastlines.
Scottish Water currently provides water and wastewater services to around 2.6 million households and more than 150,000 business premises through a network containing more than 60,000 miles of water and sewer pipes.
Plant said the extreme weather experienced during the year is increasingly becoming the new normal.
For a network carrying something Scotland rarely thinks about until it stops coming out of the tap, resilience is becoming an increasingly expensive business.
