South East Water was the worst performing company, with an increase of 59 per cent on 2010/2011 taking it to 147.1 complaints per 10,000 connections, the highest ratio by some margin. Thames Water and Southern Water also saw increases, of 13 per cent and 4 per cent respectively.
The most improved company was Welsh Water, which received 58 per cent less complaints than the previous year. Wessex Water experienced a drop of 40 per cent and United Utilities was down 31 per cent.
Tony Smith, chief executive of the Consumer Council for Water, said: “Customer complaints have been consistently decreasing since CCWater started putting pressure on water companies and identifying poor performers. Last year complaints fell at almost three times the rate of the previous year (2010/11). However, while most companies have made clear efforts to improve their service, there are still some that need to take action to address their high complaint levels.”