On April 1, water bills in England and Wales, increased by an average of six per cent. And, while the market is privatised, it is not open to competition, meaning you cannot switch provider. There is, however, one main way in which you can save money. You can opt to fit a water meter, which ties your bill to your consumption. It also recalculates the sewerage bill. If there are more bedrooms in your house than people, it is likely that a water meter will save you money, because the water rates are based upon the rentable value of your home; ie: the bigger your home is, the more you pay, whereas the water meter is based on usage. Thus, if there are only a limited number of people in the house, the usage is likely to be lower.
For a quick calculation, you can use the websites uswitch.com or consumercouncil.org.uk. Annual savings can be as much as £200.