Although most of the 1,000 people questioned said that they were happy with the services they received, three out of five thought that they were getting less value for money than they were five years ago.
Nearly half of all consumers have not recognised any improvements in service in the last few years and 70 per cent think shareholders have benefited more than customers from privatisation.
Since privatisation of the water industry in 1989, water and sewerage prices have increased by almost 40 per cent in real terms - a higher percentage than other privatised utilities.
Water companies have faced repeated criticism over giving their shareholders large dividends instead of spending money on improving the service.
One of the biggest areas of dissatisfaction uncovered by the Consumers' Association Which? report was water restrictions such as hosepipe bans which 70 per cent of people blamed on company leaks. Consumers in the North West, Severn Trent, Southern, South West Water and Yorkshire areas were the most likely to have experienced these.
Nearly a third of respondents believed that water companies have not done enough to keep public areas of water clean and almost a third felt their water company did not keep them informed, with customers of North West Water feeling particularly left in the dark.
However, 80 per cent of consumers are satisfied with the safety and appearance of their water, and 66 per cent say their water had either always tasted good or had improved.
Customers of South West Water, which has the highest water bills in the country - an average of pounds 355 unmetered - were the least happy, complaining about overall service, value for money and environmental policies.
Thames Water customers, whose average bill is the lowest at pounds 200, also reported areas of dissatisfaction, along with Anglian Water households who pay an average of pounds 325. Northumbrian water customers, paying an average of pounds 235 a year, were the happiest in the survey of 1,000 people, scoring the highest ratings.
Helen Parker, editor of Which? said the survey showed widespread customer dissatisfaction. She called on the regulator Ofwat to introduce a one- off price cut for households.