Customer pressing smiley face emoticon on wood cube, Service rating, satisfaction concept.

Our annual Water Mark assessment of water company performance

This is the sixth year of our Water Mark assessment of how well companies are performing on everything from satisfaction with service and value for money to complaint handling and sewer flooding.

We compare and grade each company using customers’ views, complaints data and operational performance (excel), based on our methodology to show how well each company has performed.

The latest annual wave of performance data shows almost 2 million struggling households are now receiving lower water bills through water companies’ social tariff schemes. This marks a 22% increase compared to the previous year, while customers receiving support through the WaterSure scheme increased by 13%.

Other key findings include:

  • Supply interruptions increased across the industry by 58% compared to 2023-24  – rising to an average of 22 minutes 39 seconds, against the target of 5 minutes for 2024-25.
  • Internal flooding of properties with sewage fell by 19% with only one company marginally increasing. External sewer flooding incidents decreased by 5%.
  • The average amount of water lost through leakage across the industry fell by 3% to 2,865 Ml/d from 2,963 Ml/d. That is the equivalent of 105 litres per property per day, compared with 109 litres per property, per day in 2023-24.
  • The number of customers in vulnerable circumstances receiving additional help through Priority Service Registers rose significantly to 3,941,386 households – up 27%.
Download Water Mark 2025 (pdf – 36 KB)
Download Data appendices 2024-25 (xlsx – 1 MB)